Well, what a year 2011 turned out to be! As I write this it will be six months since I learned that I have incurable brain cancer.
Let me tell you, nothing prepares you for the shock of being told you have a terminal illness. One day I was a reasonably fit 58-year-old who had never been seriously ill in my life, enjoyed long walks in the outdoors, didn't eat junk food, never smoked and drank only in moderation. I fully expected to live until my 80s - the average expectancy of people in Britain.
A week later and our world had been turned upside down. Within hours of being referred to hospital after complaining of a persistent slight headache and fuzzy vision I had been give a CT scan and told that there was something in my brain that shouldn't be there, something that might be a tumour.
Then I was told that whatever it was, I would need brain surgery, and asked to sign a form to show it had been explained to me that I might never recover from the operation, I might be left in a coma, or unable to speak or recognize my wife. The thought of brain surgery was scary but with no time to even think about alternatives I signed. A couple of hours after that and I was being whisked by ambulance across the breadth of the country in the middle of the night to the Royal Victoria Infirmary in Newcastle. There, they made an MRI scan and then performed the brain surgery to remove as much as they could of the tumour without harming normal brain function.
A few days later I was recovering in hospital from the operation, feeling better by the day and fully expecting that I would be home soon and in a few weeks life would get back to normal. Then a grave-faced hospital registrar accompanied by a nurse drew the curtains round my bed, sat down and informed us that the material taken from my brain had been analyzed. It was a brain tumour, and not just any old brain tumour but the worst sort possible (glioblastoma multiforme grade 4) that only one in 40,000 people are unlucky enough to get. I'd hit the brain tumour jackpot. The prognosis was from a few months to a year, but I would receive treatment to "prolong quality of life as far as possible."
The news was like being punched in the stomach. Nothing in our life would ever be the same from that moment on. And Olga and I, stunned and numb, were left to find our way home to Cockermouth from Newcastle.
Since then, we have been through a whole gamut of emotions. At first, I felt that nothing I did before I knew I had a tumour mattered as much as making the best of whatever time was left to myself and Olga. In that frame of mind I felt that ham radio was a fairly pointless activity and posted in this blog what I thought would be The Final Over.
But I soon came to realize that life wasn't over yet. Because of the need for rest and treatment, Olga and I couldn't just take ourselves off on a world cruise anyway. I needed to be available to see the doctors and go to the hospital. So I regained my interest in my hobby and was soon very thankful for it as gave me something to do during the weeks spent at home, something that took my mind off the darker thoughts I often had.
Learning that I had a brain tumour and that my life was likely to be shorter than I had hitherto expected has made me a different person. I now live from day to day and try to be grateful for whatever each day brings me. I used to be the archetypal "grumpy old man" ranting about the government or other people. I haven't altered my opinions about bankers, politicians and the EU but now I don't waste precious time grumbling about things I can't change.
After I began writing my brain tumour diary one or two people pointed out that it wasn't just me, we are all mortal and we all die eventually. Some people go off to work and die in car accidents or suddenly drop dead of a heart attack giving their loved ones no opportunity even to say goodbye to them. Others die after long and painful illnesses with months in hospital. We don't know for how long the treatment will keep my tumour at bay. At the moment I'm feeling no pain, just frustration sometimes at not being able to do things I could when I was fit. But I'm at home with my wife and expecting that I will eventually get back to something more akin to normal.
The realization that time is precious means that Olga and I will do things that we otherwise would probably never have got around to. I am lucky that I have been able to give up work and devote my energy exclusively to recovery and recreation. We are both savers not borrowers so we are fortunate not to have money worries - well, not apart from the possibility of a world economic collapse making all of our savings worthless! Being diagnosed with a terminal illness has even allowed me to fulfil a goal I thought I never would - that of retiring before I was 60. Every cloud has a silver lining.
Most of all, I am so fortunate to be married to my wife and soulmate Olga. She has never once complained about the stresses and strains of suddenly finding her husband has brain cancer. She is always there for me, making sure I take all the right pills at the right time and helping me keep my strength up with lots of tasty home-cooked food, fruit and vegetables.
My situation has been harder for Olga to bear than for me. I have always had a bit of a fatalistic view of life - that what will be will be - and a tendency to look for dark humour in a situation. But I only have to imagine how I would feel if the situation was reversed to know how Olga must be feeling. I would be heartbroken to lose her and it won't be easy for her if she loses me.
For Olga, even more than for myself, I need to beat this tumour. I need to prove the doctors wrong and show that you can survive a glioblastoma. I'm optimistic about it. So my one and only resolution for 2012 is to beat the bugger and still be here in a year's time to write about all the things we have done despite my having a brain tumour.
Thank you for reading my blog and for all the messages and cards of support sent by many of you. They have all made a difference and helped us both to feel better about the situation. I hope that 2012 will be a great year for you and not spring any nasty surprises like 2011 did for us.
Friday, December 30, 2011
Simple keyer trouble
It should have been simple. I needed a basic CW keyer that would allow me to use a paddle with my homebrew QRP / QRPP rigs because my shaky hands make sending Morse with a straight key too difficult at the moment. I also needed to be able to record a message and play it once or repeatedly until I heard someone reply or was spotted on the reverse beacon network.
A couple of years ago I built a DC20B QRP transceiver. I didn't like it very much and eventually sold it on eBay but I did like the keyer built into it which used an ATTiny13 microcontroller. One day, I thought, I would build a keyer using this chip. I got two of the Atmel chips and Steve Weber KD1JV sent me the hex file so I could program them but I never got around to doing anything more until a couple of days ago.
The simple keyer circuit uses only a handful of components but due to my condition it took a lot longer than it would have done pre-tumour to work out a perf board layout and build it. So you can imagine that I was a bit upset when after all that effort the keyer didn't work. It responded to the dash key and the function button, but not the dot key. Also the sidetone was very high pitched and the Morse speed was about 100wpm!
Thinking I had made a mistake programming the clock setting in the chip I tried programming the other one. This ended up just the same. Unfortunately with the simple keyer program you have to disable the reset pin that is used by the programmer so you only get one chance to write the code to the EPROM. But as I don't have the source code and so can't try modifying it that shouldn't have been a problem. If I hadn't sold the DC20B I could have tried the keyer chip from that, but now I am now stuck with no idea what to try next.
I have the code for another keyer that uses a PIC12F509A - the K9 from K1EL's freeware page. But I'd have to start over with the circuit board as the pinouts of the Atmel and Microchip microcontrollers are not compatible. The functionality of the K1EL keyer program is not what I was after either, so I don't feel much like trying it at the moment.
A couple of years ago I built a DC20B QRP transceiver. I didn't like it very much and eventually sold it on eBay but I did like the keyer built into it which used an ATTiny13 microcontroller. One day, I thought, I would build a keyer using this chip. I got two of the Atmel chips and Steve Weber KD1JV sent me the hex file so I could program them but I never got around to doing anything more until a couple of days ago.
The simple keyer circuit uses only a handful of components but due to my condition it took a lot longer than it would have done pre-tumour to work out a perf board layout and build it. So you can imagine that I was a bit upset when after all that effort the keyer didn't work. It responded to the dash key and the function button, but not the dot key. Also the sidetone was very high pitched and the Morse speed was about 100wpm!
Thinking I had made a mistake programming the clock setting in the chip I tried programming the other one. This ended up just the same. Unfortunately with the simple keyer program you have to disable the reset pin that is used by the programmer so you only get one chance to write the code to the EPROM. But as I don't have the source code and so can't try modifying it that shouldn't have been a problem. If I hadn't sold the DC20B I could have tried the keyer chip from that, but now I am now stuck with no idea what to try next.
I have the code for another keyer that uses a PIC12F509A - the K9 from K1EL's freeware page. But I'd have to start over with the circuit board as the pinouts of the Atmel and Microchip microcontrollers are not compatible. The functionality of the K1EL keyer program is not what I was after either, so I don't feel much like trying it at the moment.
Thursday, December 22, 2011
Season's Greetings
Olga and I send our best wishes for the festive season and New Year 2012
to all of our readers and well-wishers.
Tuesday, December 20, 2011
Latest QSLs
A batch of QSLs just arrived from the RSGB Bureau. Here are a few of the more attractive ones. Enjoy!
Sunday, December 18, 2011
More EU madness
I'm not the first blogger to mention this item of news but it is certainly one topic that I could not allow to pass by without comment. According to the IARU Region 1 website, the EU Commission will be revising the EMC Directive and removing the exemption of amateur radio kits and modified equipment from its provisions. Products that are currently exempted would be subject to inspection and certification, a process which would make the production of kits hopelessly uneconomic. It would also potentially spell the end of home building and modification and prevent the importation of kits from the USA and other havens of relative sanity. No, this isn't one of my April 1st spoof stories released from the Drafts folder by mistake!
I would hope that the IARU, the RSGB and other European amateur radio societies will make urgent representations to the EC to stop this proposal. But this is just one scary example of why I and many other like-minded people feel that we in the UK would be better off out of the European Union.
In fact, most of Europe would be better off without it in my opinion. Could somebody explain why, at a time when European governments are supposed to be cutting back on public expenditure, they continue contributing billions every year (only recently having voted an increase - the UK alone contributes £51 million per day) in order to fund this unelected and unaccountable Commission to employ people who live in cloud cuckoo land to produce unwanted, unnecessary and unasked-for legislation?
I would hope that the IARU, the RSGB and other European amateur radio societies will make urgent representations to the EC to stop this proposal. But this is just one scary example of why I and many other like-minded people feel that we in the UK would be better off out of the European Union.
In fact, most of Europe would be better off without it in my opinion. Could somebody explain why, at a time when European governments are supposed to be cutting back on public expenditure, they continue contributing billions every year (only recently having voted an increase - the UK alone contributes £51 million per day) in order to fund this unelected and unaccountable Commission to employ people who live in cloud cuckoo land to produce unwanted, unnecessary and unasked-for legislation?
Are you ready for Doomsday?
One of the blogs I read this morning contained a link to this article in the Mail Online "Stocking up for Doomsday." The scenario it describes might seem to many of you a bit far-fetched but there are quite a few Americans who wouldn't think so. You don't have to look far to find web forums where people discuss survival plans. These people have guns to defend their families and their food and fuel store. They will use ham radios to communicate when the phones and internet are down.
This Doomsday picture doesn't seem so far-fetched to my wife Olga. Few people in the West even know about this as it received hardly any coverage in the media at the time but in 1992 after the collapse of the Soviet Union Ukraine went bankrupt. Ukrainians who had money in the bank lost it all (and most have still never been compensated for it.) Food disappeared from the shops - not that there was much to start with. People stood on station platforms and begged for food from trains travelling through to Moscow. For years Olga suffered from stomach problems as a legacy from that period when she almost starved. Yes, this happened in a developed country that is right next door to Europe.
The Ukraine government allocated plots of land so people could create kitchen gardens and grow their own food but these were usually a long way from where people lived and anything you did manage to grow got stolen. Olga and her mother avoided complete starvation only because her mother had food coupons as a war veteran which entitled her to obtain military rations.
It's easy to think "it couldn't happen here" but the number of economists who are starting to predict a complete economic collapse is enough to make you start wondering if that is just being complacent. Most of us older people who have savings for our retirement have already experienced anxiety about the security of those savings. We naively trust that the British government will honour its promises to guarantee the first £50,000 of individual savings held in British banks but how do we know it could afford to? And how long would it be before we received that compensation? We'd have starved long before, I'm sure of it.
And what about businesses, whose deposits are not guaranteed: businesses that we imagine would provide the food and services that we would need but which wouldn't have the money to keep trading? Panic buying will have long since emptied the shops of food. What would we do then? Make soup out of five pound notes?
Happy New Year? I wonder.
This Doomsday picture doesn't seem so far-fetched to my wife Olga. Few people in the West even know about this as it received hardly any coverage in the media at the time but in 1992 after the collapse of the Soviet Union Ukraine went bankrupt. Ukrainians who had money in the bank lost it all (and most have still never been compensated for it.) Food disappeared from the shops - not that there was much to start with. People stood on station platforms and begged for food from trains travelling through to Moscow. For years Olga suffered from stomach problems as a legacy from that period when she almost starved. Yes, this happened in a developed country that is right next door to Europe.
The Ukraine government allocated plots of land so people could create kitchen gardens and grow their own food but these were usually a long way from where people lived and anything you did manage to grow got stolen. Olga and her mother avoided complete starvation only because her mother had food coupons as a war veteran which entitled her to obtain military rations.
It's easy to think "it couldn't happen here" but the number of economists who are starting to predict a complete economic collapse is enough to make you start wondering if that is just being complacent. Most of us older people who have savings for our retirement have already experienced anxiety about the security of those savings. We naively trust that the British government will honour its promises to guarantee the first £50,000 of individual savings held in British banks but how do we know it could afford to? And how long would it be before we received that compensation? We'd have starved long before, I'm sure of it.
And what about businesses, whose deposits are not guaranteed: businesses that we imagine would provide the food and services that we would need but which wouldn't have the money to keep trading? Panic buying will have long since emptied the shops of food. What would we do then? Make soup out of five pound notes?
Happy New Year? I wonder.
Friday, December 16, 2011
Snow!
This was the scene that greeted me when I looked outside this morning! Nothing to what folks in the USA get, of course. But considering that it used to be unusual to have any snow at all during the winter here in West Cumbria it's still noteworthy.
I hope we don't get any more, though. Apart from the hassle factor of slushy slippery pavements, a thick layer of snow on the roof won't help my attic antennas to get out.
Thursday, December 15, 2011
VOAProp and WWV
A couple of days ago I received an email from Mirek, OK1DUB, to let me know that, due to a small change in the format of the Geophysical Alert from WWV (http://www.swpc.noaa.gov/ftpdir/latest/wwv.txt) VOAProp is no longer able to process it, reporting that the format is invalid.
Mirek has written a PHP script to run on his server (http://ok1dub.cz/ham/) which reads the original WWV file every 5 minutes and creates a new version using the old format. This file can be accessed at http://ok1dub.cz/wwv/wwv.txt . When I first tried it, the server was very slow to respond and I was afraid that it might not be able to handle the hundreds of daily requests made by the tens of thousands of copies of VOAProp that are out there. But this was apparently only a temporary problem. I have tried the file again today and it loads quickly. Mirek says he is happy to allow public usage.
A page explaining what Mirek has done (and disclaiming responsibility for any error) is here.
What you need to do is:
Mirek has written a PHP script to run on his server (http://ok1dub.cz/ham/) which reads the original WWV file every 5 minutes and creates a new version using the old format. This file can be accessed at http://ok1dub.cz/wwv/wwv.txt . When I first tried it, the server was very slow to respond and I was afraid that it might not be able to handle the hundreds of daily requests made by the tens of thousands of copies of VOAProp that are out there. But this was apparently only a temporary problem. I have tried the file again today and it loads quickly. Mirek says he is happy to allow public usage.
A page explaining what Mirek has done (and disclaiming responsibility for any error) is here.
What you need to do is:
- In VOAProp, click the Solar Data button to open the window that displays the WWV file.
- In the Data URL field, enter the address of the replacement file which is http://ok1dub.cz/wwv/wwv.txt .
Wednesday, December 14, 2011
SDR Radio
An early Christmas present to myself is this SDR-4 HF receiver from Cross Country Wireless. Actually, it wasn't intended to be a Christmas present. I decided to get one a couple of months ago when I first found out about it.
I think the SDR-4 is the lowest cost ready built HF bands software defined radio on the market (£150 or about $250 US). Unless you know different, of course. However it seems that a lot of other people thought so too, as there is a waiting list - people are ordering them faster than the designer Chris G4HYG can make them!
The SDR-4 works with the usual free SDR applications. But it also works with the free version of Simon Brown HB9DRV's SDR-Radio.com application. This is the best SDR software by a mile, though due to all the treatment and medication I am receiving for my brain tumour my mind is a bit slow at the moment and I find figuring out how to do what I want with it a bit challenging.
As you might expect from the author of Ham Radio Deluxe, SDR-Radio.com has built-in support for decoding digital modes. Unfortunately I haven't managed to work out yet how to get the digital decoder waterfall to be a reasonable size: At the moment it's a small window on the left hand side which is trying to display 15kHz worth of spectrum and although I'm hearing PSK31 I can't find a trace to click on! I'm also still trying to discover if there is a PSK Browser in the program that sends reports to the PSK Reporter reverse beacon site. Hopefully someone will enlighten me.
I'm sure I'll be writing more about the SDR-4 receiver and SDR-Radio.com in due course, but in the meantime if you want more information or to ask questions about the receiver there is a Cross Country Wireless Yahoo! group. You can even try an SDR-4 out over the Internet if you follow the instructions posted by Chris. I did and it worked perfectly - and it was so nice to hear the amateur bands without the awful frying noise I have to endure here.
Yahoo! is also the place to go for information and support of SDR-Radio.com (the software.) I look forward to seeing some comments and experiences of any of my readers who are tempted into trying this software defined radio.
I think the SDR-4 is the lowest cost ready built HF bands software defined radio on the market (£150 or about $250 US). Unless you know different, of course. However it seems that a lot of other people thought so too, as there is a waiting list - people are ordering them faster than the designer Chris G4HYG can make them!
The SDR-4 works with the usual free SDR applications. But it also works with the free version of Simon Brown HB9DRV's SDR-Radio.com application. This is the best SDR software by a mile, though due to all the treatment and medication I am receiving for my brain tumour my mind is a bit slow at the moment and I find figuring out how to do what I want with it a bit challenging.
As you might expect from the author of Ham Radio Deluxe, SDR-Radio.com has built-in support for decoding digital modes. Unfortunately I haven't managed to work out yet how to get the digital decoder waterfall to be a reasonable size: At the moment it's a small window on the left hand side which is trying to display 15kHz worth of spectrum and although I'm hearing PSK31 I can't find a trace to click on! I'm also still trying to discover if there is a PSK Browser in the program that sends reports to the PSK Reporter reverse beacon site. Hopefully someone will enlighten me.
I'm sure I'll be writing more about the SDR-4 receiver and SDR-Radio.com in due course, but in the meantime if you want more information or to ask questions about the receiver there is a Cross Country Wireless Yahoo! group. You can even try an SDR-4 out over the Internet if you follow the instructions posted by Chris. I did and it worked perfectly - and it was so nice to hear the amateur bands without the awful frying noise I have to endure here.
Yahoo! is also the place to go for information and support of SDR-Radio.com (the software.) I look forward to seeing some comments and experiences of any of my readers who are tempted into trying this software defined radio.
Tuesday, December 13, 2011
Link between radio use and brain tumours?
A news item in the December 2011 CQ magazine caught my attention yesterday. It reported that a Danish study of more than 350,000 people found no evidence of a link between cellphone use and cancer. Cancer rates have not increased during the time that cellphone use has become widespread. "That's good news" I thought.
However, some websites that reported the story carried the additional information that the Danish researchers found a hint of a link between heavy phone use and the rare but usually fatal glioma brain tumours - exactly the bugger I have. Not such good news after all, then.
Another study by Swedish researchers found an increase in cancer in areas of the brain exposed to microwave energy during a mobile phone call. Most of this data was from users of older analogue phones which run higher power and cause three times the exposure of newer digital systems. However that would still apply to use of VHF and UHF FM hand-helds which are typically operated at a power of 5 watts.
I think you would have to be an extremely active ham radio operator to expose yourself to as much RF as a heavy mobile phone user. But most hams are using much lower frequencies - though potentially higher power levels. Are the frequencies commonly used by hams more or less likely to cause cancer? I don't think anyone definitively knows the answer to that.
But it is certainly food for thought. I'd be more inclined now to use my HTs on low power or with a speaker mic so as to get the antenna further from the head. And if you must use indoor or stealth antennas that can only be sited a few feet from the operating position, life's too short for QRO!
However, some websites that reported the story carried the additional information that the Danish researchers found a hint of a link between heavy phone use and the rare but usually fatal glioma brain tumours - exactly the bugger I have. Not such good news after all, then.
Another study by Swedish researchers found an increase in cancer in areas of the brain exposed to microwave energy during a mobile phone call. Most of this data was from users of older analogue phones which run higher power and cause three times the exposure of newer digital systems. However that would still apply to use of VHF and UHF FM hand-helds which are typically operated at a power of 5 watts.
I think you would have to be an extremely active ham radio operator to expose yourself to as much RF as a heavy mobile phone user. But most hams are using much lower frequencies - though potentially higher power levels. Are the frequencies commonly used by hams more or less likely to cause cancer? I don't think anyone definitively knows the answer to that.
But it is certainly food for thought. I'd be more inclined now to use my HTs on low power or with a speaker mic so as to get the antenna further from the head. And if you must use indoor or stealth antennas that can only be sited a few feet from the operating position, life's too short for QRO!
Wednesday, December 07, 2011
Still alive and kicking (just!)
It has been a while since my last posting to this blog, which has caused a couple of readers to express concern about my current state of health. I'm glad to say that reports of my demise are exaggerated, but less happy that the intensive chemotherapy regime has left me feeling pretty lousy and afflicted with a severe lethargy that nothing less than the arrival of Santa Claus bearing a shiny new Elecraft KX3 could kick me out of. Even reports that 10 metres is wide open have not given me the energy to haul my ass into the shack and see for myself. Hence the lack of posts.
I don't see things getting much better for the next 4 months when the chemotherapy will be over as although I do detect an improvement in how I feel as I get towards the end of a cycle I am quickly back to square one after starting the next one. There is not enough change in how I feel from day to day to warrant more frequent postings to One Foot in the Grave. My days seem to merge together so that most of the time I couldn't even tell you what day of the week it is!
Despite what I have just written I will not actually be one of the people feverishly refreshing the Elecraft order page in order to secure a place near the top of the list for KX3 orders. Though I don't doubt that the KX3 is a seriously cool piece of radio equipment that will be a big success for Elecraft, I have come to the decision that my FT-817ND meets all my current needs of a portable ham radio. I also can still remember my frustration at the length of time I had to wait to receive my K3 (and the even longer wait until the firmware actually worked and it all performed as expected.) I don't wish to cause myself the stress of wondering whether I will live long enough to receive my KX3!
That's not to say I don't see an Elecraft KX3 in my life (and my shack) at any point. I can envisage a situation where a new toy to play with could make life seem a lot more cheerful. One day it will be possible to order a KX3 and get instant gratification. But until then I'll content myself with reading the experiences of the early adopters and watching their YouTube videos.
Sunday, November 20, 2011
Flummoxed!
In the APRS world a new piece of software has been creating some excitement. It is a soundcard modem for packet radio by UZ7HO. It runs under Windows and emulates the AGW Packet Engine so that it can be used by any program that is designed to work with it. The reason for the excitement is that this packet modem can decode several packet signals on slightly different frequencies in parallel, resulting in many more decodes on HF where it is quite common for stations to be 50Hz or more off-frequency.
Unfortunately I haven't been able to try the new packet engine as the PTT won't key my Elecraft K2 and I don't know why. My K2 CAT cable has a transistor switch on the DTR line which goes to a 3.5mm jack plug that plugs in the K2 key socket. This was originally used for computer Morse keying using software like MixW, but it can also be used for PTT with digital mode software as the key and PTT lines are common. Using fldigi and even using a serial port test program I am able to activate the DTR line on COM2 and the K2 will respond by switching to transmit. But if I use this software modem no PTT ever occurs so although the audio is generated the packet signal is never transmitted. If I was using a SignalLink or other device such as my homebrew USBlink with fast audio derived VOX then this wouldn't matter but as I have a PTT connection on this serial port I'd really prefer to make use of it.
If I change the serial port to COM3 then the program will key my Elecraft K3, which uses a different serial cable but still uses DTR for PTT. I tried the original AGW Packet Engine, both free and paid-for Pro versions but that won't key the K2 either. So the problem must be something to do with my K2 CAT cable. But my poor old brain has been having rather a tough time recently with all the treatment making me feel like a bit of a zombie and I'm finding it rather difficult to think things through logically and find the solution which is probably staring me in the face!
Unfortunately I haven't been able to try the new packet engine as the PTT won't key my Elecraft K2 and I don't know why. My K2 CAT cable has a transistor switch on the DTR line which goes to a 3.5mm jack plug that plugs in the K2 key socket. This was originally used for computer Morse keying using software like MixW, but it can also be used for PTT with digital mode software as the key and PTT lines are common. Using fldigi and even using a serial port test program I am able to activate the DTR line on COM2 and the K2 will respond by switching to transmit. But if I use this software modem no PTT ever occurs so although the audio is generated the packet signal is never transmitted. If I was using a SignalLink or other device such as my homebrew USBlink with fast audio derived VOX then this wouldn't matter but as I have a PTT connection on this serial port I'd really prefer to make use of it.
If I change the serial port to COM3 then the program will key my Elecraft K3, which uses a different serial cable but still uses DTR for PTT. I tried the original AGW Packet Engine, both free and paid-for Pro versions but that won't key the K2 either. So the problem must be something to do with my K2 CAT cable. But my poor old brain has been having rather a tough time recently with all the treatment making me feel like a bit of a zombie and I'm finding it rather difficult to think things through logically and find the solution which is probably staring me in the face!
Friday, November 11, 2011
Not so chirpy
Yesterday I attempted to have a QSO using the XBM-10-2 two transistor "Chirpy" transceiver for 10m. I asked Jim, G3XPD, who is about 8km south of G4ILO to listen out for me. Jim could hear the distinctive sound of my 100mW transmission, but I could not hear Jim, not even when he called using 100W.
I know the Chirpy receiver works because I can receive a locally generated signal such as my antenna analyzer. But I guess even that is a big signal compared to one received off the air. I need to find a way to improve the receive sensitivity if it is to be possible to make a real two-way contact using this simple transceiver circuit.
I have tried adjusting C2 for maximum noise in the earpiece rather than maximum output when the key is down, to see if that gives some improvement. If nothing else it seems to have tamed the chirp a bit.
I know the Chirpy receiver works because I can receive a locally generated signal such as my antenna analyzer. But I guess even that is a big signal compared to one received off the air. I need to find a way to improve the receive sensitivity if it is to be possible to make a real two-way contact using this simple transceiver circuit.
I have tried adjusting C2 for maximum noise in the earpiece rather than maximum output when the key is down, to see if that gives some improvement. If nothing else it seems to have tamed the chirp a bit.
Wednesday, November 09, 2011
Feeling chirpy
Not without some difficulty due to my shaking hands, I managed to modify my copy of Roger G3XBM's XBM-10-2 two transistor transceiver for 10m to his latest version. It is now named the "Chirpy" for reasons that will become obvious when you hear one on the air.
My version is exactly the same as Roger's except that R3 is a trimpot not a fixed resistor. This allows me to adjust the power output to what I want. I am getting 150mW output on a 13.8V supply, this drops to 50mW with a 9V power source.
So far I have yet to make a contact with the little rig. I have called CQ on 28.060 many times but my signal is yet to be spotted on the Reverse Beacon Network. I don't know if that is because my signal is too weak or too chirpy for decoding by the skimmer stations. Or perhaps the skimmers don't receive that far up the 10m band. I will probably have to arrange a sked with a local station who is near enough to hear me.
My version is exactly the same as Roger's except that R3 is a trimpot not a fixed resistor. This allows me to adjust the power output to what I want. I am getting 150mW output on a 13.8V supply, this drops to 50mW with a 9V power source.
So far I have yet to make a contact with the little rig. I have called CQ on 28.060 many times but my signal is yet to be spotted on the Reverse Beacon Network. I don't know if that is because my signal is too weak or too chirpy for decoding by the skimmer stations. Or perhaps the skimmers don't receive that far up the 10m band. I will probably have to arrange a sked with a local station who is near enough to hear me.
Thursday, October 27, 2011
Two Transistor Tranceiver for Ten
With ten metres opening up it seemed the right time to try building Roger G3XBM's latest project: the XBM10-2. Roger describes it as probably just about the simplest CW transceiver possible for use on 10m, using just two transistors to produce about 60mW out.
This was my first attempt at construction since my radiotherapy and chemotherapy and I found it to be quite a struggle. First of all I found it difficult to concentrate while trying to work out the perf board layout. After that I got a bit frustrated with constantly juggling three pairs of spectacles due to my eyes apparent inability to focus at different distances. I also found soldering difficult due to my hands shaking whenever I brought the iron bit close to a component. I created quite a few solder bridges which I then had to clean up.
Construction took much longer than I would have taken a few months ago. But in the end it did work. Though not on ten metres yet. I'm waiting for a 28.060MHz crystal from the G-QRP club shop before I can try it out on the air.
One issue I have found (which Roger also comments on) is that the rig has a major chirp. It is definitely not T9 and I don't know whether it is possible to improve on that. But at least it has character. If you hear a weak, chirpy signal near to the 10m QRP activity frequency give it a call. It might be me!
This was my first attempt at construction since my radiotherapy and chemotherapy and I found it to be quite a struggle. First of all I found it difficult to concentrate while trying to work out the perf board layout. After that I got a bit frustrated with constantly juggling three pairs of spectacles due to my eyes apparent inability to focus at different distances. I also found soldering difficult due to my hands shaking whenever I brought the iron bit close to a component. I created quite a few solder bridges which I then had to clean up.
Construction took much longer than I would have taken a few months ago. But in the end it did work. Though not on ten metres yet. I'm waiting for a 28.060MHz crystal from the G-QRP club shop before I can try it out on the air.
One issue I have found (which Roger also comments on) is that the rig has a major chirp. It is definitely not T9 and I don't know whether it is possible to improve on that. But at least it has character. If you hear a weak, chirpy signal near to the 10m QRP activity frequency give it a call. It might be me!
Friday, October 21, 2011
Happy Birthday Olga!
Today is my wonderful wife Olga's 60th birthday. Without her amazing help and support I don't know if I would have the strength to cope with this brain tumour. I keep up the fight so that I will still be here to help celebrate the next one. Happy 60th birthday, Olga!
Albrecht AE 2990 AFS mods
With propagation on 10m being so good I have been trying to make some contacts using the Albrecht AE2990AFS multimode handheld using a whip antenna. No luck so far, however.
One annoying aspect of the Albrecht is that it tunes in 10kHz steps since it is essentially a CB radio. There is a step control that lets you choose 1kHz or 50Hz tuning steps, but this only works within one 10kHz or 1kHz range. You can't tune the whole band in these smaller steps. Not only that but the clarifier control (better known to hams as RIT) shifts only the receive frequency and doesn't have a centre detent so you can never be sure you are calling a station on his exact frequency.
An eBay seller of the Super Radio SS-301 - which seems to be the same radio as the Albrecht under another name - claims that the clarifier works on both TX and RX. So there is presumably a modification that would make the clarifier work like a VXO. But I'm darned if I can find any details of it. Has anyone made such a modification to this radio?
One annoying aspect of the Albrecht is that it tunes in 10kHz steps since it is essentially a CB radio. There is a step control that lets you choose 1kHz or 50Hz tuning steps, but this only works within one 10kHz or 1kHz range. You can't tune the whole band in these smaller steps. Not only that but the clarifier control (better known to hams as RIT) shifts only the receive frequency and doesn't have a centre detent so you can never be sure you are calling a station on his exact frequency.
An eBay seller of the Super Radio SS-301 - which seems to be the same radio as the Albrecht under another name - claims that the clarifier works on both TX and RX. So there is presumably a modification that would make the clarifier work like a VXO. But I'm darned if I can find any details of it. Has anyone made such a modification to this radio?
Wednesday, October 19, 2011
Radio Tirana
Propagation on 10m today is as good as I can remember. I made a few nice contacts using SSB including Japan, India and Bahrain. I heard several Chinese stations as well but have yet to work one.
Not really DX but a new country for me was Albania, in the shape of Dik, ZA1E. Decades ago as a teenaged short wave listener I remember hearing Radio Tirana, a huge signal on 7.065MHz, smack in the middle of the 40m phone band. I wonder whether anyone ever listened to its broadcasts? They were pure anti-capitalist tirades read by a woman announcer who sounded like she had a beard and no sense of humour. They actually used phrases like "capitalist running dogs" if I remember correctly. At least Radio Moscow tried to make life on the other side of the iron curtain sound attractive.
I don't think there was any ham radio activity in communist Albania and there still aren't all that many hams there now so I was pleased to work Dik for a new one.
Not really DX but a new country for me was Albania, in the shape of Dik, ZA1E. Decades ago as a teenaged short wave listener I remember hearing Radio Tirana, a huge signal on 7.065MHz, smack in the middle of the 40m phone band. I wonder whether anyone ever listened to its broadcasts? They were pure anti-capitalist tirades read by a woman announcer who sounded like she had a beard and no sense of humour. They actually used phrases like "capitalist running dogs" if I remember correctly. At least Radio Moscow tried to make life on the other side of the iron curtain sound attractive.
I don't think there was any ham radio activity in communist Albania and there still aren't all that many hams there now so I was pleased to work Dik for a new one.
Tuesday, October 18, 2011
Battery boost
A couple of years ago I won a 25 year old "spares or repair" Kenwood TH-205E for a few pounds in an eBay auction. I successfully repaired it, but the ni-cad pack had failed short-circuit. I then had a stroke of luck as I found someone selling an 25 year old but unused KNB-4 battery pack for a couple of quid. It held a charge, so the problem was solved. The only disadvantage was that it was the large high capacity battery pack, much taller than the original, making the radio even bulkier than it already is. I nicknamed it "the brick."
A few days ago I was looking at the Strikalite web site and noticed that they do battery pack refurbishment. I enquired whether they could repair the 205E's original battery pack. "Send it to us and we'll take a look at it" they said, so I did.
A few days later I received a phone call from Strikalite saying "We need to take some money off you." I was a bit concerned as to how much it would be as they had not provided me with an estimate before starting. But I need not have worried. The total cost including postage and VAT was £19.99 which I think is very reasonable. They did quite a neat job, with only a little marking of the case where they had to pry the two halves apart.
£20 may seem like more than a 25 year old boat anchor that doesn't support 12.5kHz spacing nor CTCSS for repeater access is worth. But actually the TH-205E has the best, most intermod-resistant receiver of any of my HTs due to the fact that it is designed for the 2m band only, not wide band coverage. If I ever get out on the fells again, the TH-205E would be a strong candidate to take. There's life in the old thing yet!
A few days ago I was looking at the Strikalite web site and noticed that they do battery pack refurbishment. I enquired whether they could repair the 205E's original battery pack. "Send it to us and we'll take a look at it" they said, so I did.
A few days later I received a phone call from Strikalite saying "We need to take some money off you." I was a bit concerned as to how much it would be as they had not provided me with an estimate before starting. But I need not have worried. The total cost including postage and VAT was £19.99 which I think is very reasonable. They did quite a neat job, with only a little marking of the case where they had to pry the two halves apart.
£20 may seem like more than a 25 year old boat anchor that doesn't support 12.5kHz spacing nor CTCSS for repeater access is worth. But actually the TH-205E has the best, most intermod-resistant receiver of any of my HTs due to the fact that it is designed for the 2m band only, not wide band coverage. If I ever get out on the fells again, the TH-205E would be a strong candidate to take. There's life in the old thing yet!
Monday, October 17, 2011
Radio Therapy
Ten metres has been really lively today. I made several contacts including some with the USA. The highlight was working Osama, 9K2OD in Kuwait City who came back to my first call (SSB) even though he had a bit of a pile-up! Perhaps my attic dipole and QTH are not so shabby after all!
It's great to experience propagation conditions like this again and it cheers me up no end. Real radio therapy!
It's great to experience propagation conditions like this again and it cheers me up no end. Real radio therapy!
Thursday, October 13, 2011
Monday, October 10, 2011
Long wave goodbye
I never did get the Spectrum Communications Off-Air Frequency Standard kit working. Now it is looking as though it would be a waste of time anyway as the BBC will be closing down the Radio 4 long wave transmitter that is used as a frequency standard.
An article published yesterday in the Guardian Online explains that the Radio 4 long wave transmitter uses valves (tubes) that are no longer obtainable. The BBC has the only ones still in existence. The transmitter uses a pair and they can last as little as one year. When the last valve blows, Radio 4 on long wave will become a thing of the past.
Building a new long wave transmitter using up to date technology would cost millions which the BBC can no longer afford due to the need to cut costs as a result of the government's decision to freeze the licence fee.
There are many other ways to receive the Radio 4 programming if the long wave transmitter closes down. But none of them involve a powerful 500kW transmitter whose frequency is maintained accurately enough to be used as a frequency standard.
An article published yesterday in the Guardian Online explains that the Radio 4 long wave transmitter uses valves (tubes) that are no longer obtainable. The BBC has the only ones still in existence. The transmitter uses a pair and they can last as little as one year. When the last valve blows, Radio 4 on long wave will become a thing of the past.
Building a new long wave transmitter using up to date technology would cost millions which the BBC can no longer afford due to the need to cut costs as a result of the government's decision to freeze the licence fee.
There are many other ways to receive the Radio 4 programming if the long wave transmitter closes down. But none of them involve a powerful 500kW transmitter whose frequency is maintained accurately enough to be used as a frequency standard.
Friday, October 07, 2011
20 over 9 into Michigan
Propagation has again been excellent on 10m. I heard many US stations and other DX at good strength. I didn't make many contacts, though. Most of the stations I was hearing were enjoying 5 or 10 minute QSOs. You can use up a lot of time listening to such contacts, especially when you make your call and the station you are hoping to work replies to someone else and not you, so you get to wait another 5 or 10 minutes for the next chance.
Not that I'm complaining. But it doesn't help that I refuse to use bad operating tactics to get a contact. One station I waited for got angry and went QRT because other European stations were calling over the final of the station he was working. If I can only hear the DX side of the conversation I won't call until I hear the DX call CQ or say QRZ or listening for any calls. Others do, and too often they get rewarded with a contact. It makes me angry, too.
My first contact of the day was with UT1AN Alex on 10m FM. His QTH is not far from Kharkiv, Olga's home town. Alex gave me an S9+20dB report.
The last - so far, anyway, was on 10m SSB with W8ERN Angelo in Brighton, Michigan, pictured right. I waited a long time before my call was heard. But it was worth the wait because Angelo replied with are you the G4ILO that wrote the VOAProp software? I 'fessed up and Angelo told me how much he liked the program.
We also talked about web pages and logging programs. Angelo's web page is produced using a software program called CommCat Live. You can hear live streaming audio from his station and see a graphical S meter plot of the station he is receiving. He told me my signal - 100w to the attic dipole - was almost peaking 20 over 9 and sure enough when I looked at the screen it was. Perhaps my QTH is not so bad after all.
Here is the proof: W8ERN's web page snapped while I was in QSO with him.
CommCat certainly adds interest to a ham radio web page. Unfortunately - but not surprisingly - it doesn't support my home-written logging program KComm.
Not that I'm complaining. But it doesn't help that I refuse to use bad operating tactics to get a contact. One station I waited for got angry and went QRT because other European stations were calling over the final of the station he was working. If I can only hear the DX side of the conversation I won't call until I hear the DX call CQ or say QRZ or listening for any calls. Others do, and too often they get rewarded with a contact. It makes me angry, too.
My first contact of the day was with UT1AN Alex on 10m FM. His QTH is not far from Kharkiv, Olga's home town. Alex gave me an S9+20dB report.
The last - so far, anyway, was on 10m SSB with W8ERN Angelo in Brighton, Michigan, pictured right. I waited a long time before my call was heard. But it was worth the wait because Angelo replied with are you the G4ILO that wrote the VOAProp software? I 'fessed up and Angelo told me how much he liked the program.
We also talked about web pages and logging programs. Angelo's web page is produced using a software program called CommCat Live. You can hear live streaming audio from his station and see a graphical S meter plot of the station he is receiving. He told me my signal - 100w to the attic dipole - was almost peaking 20 over 9 and sure enough when I looked at the screen it was. Perhaps my QTH is not so bad after all.
Here is the proof: W8ERN's web page snapped while I was in QSO with him.
CommCat certainly adds interest to a ham radio web page. Unfortunately - but not surprisingly - it doesn't support my home-written logging program KComm.
Thursday, October 06, 2011
CB interlopers
Propagation remains good on 10 metres. I left the K3 on 28.076 running JT65-HF for most of the day. I made several contacts including N3CAL, WA2CRB, PY8ELO, KE1AF, WB9OTX, WK8G and SV4FFK. The map shows where my signal was heard. I was even spotted by Joe, W6CQZ/4, the author of the excellent JT65-HF software.
JT65 is addictive. It's also a very relaxing way to make QSOs. It's ideal for me at the moment because my eyes tire very easily. I end up with blurred or double vision if I read or stare at the computer screen for too long so modes like PSK31 aren't really a good idea. Thanks to the JT65-HF add-on JT-Alert an alarm sounds if a station I haven't worked before calls CQ and another sound wakes me up if a station replies to me. This means that I can look out the window or something and only need look at the screen when I have something to do. The print in the JT65-HF program window is nice and big too.
Listening on 28.076 I heard some strange noises which I eventually realized were FM transmissions being received in SSB mode. CBers transmitting out of band I presume.
I don't suppose many CBers read this blog but come on, guys. It's none of my business if you choose to operate illegally but if you do, please stay below 28MHz. You may not hear our weak JT65 signals with your FM radios but we sure as hell can hear you.
Update: Just worked Joe "The Man" W6CQZ/4 in Florida. He was running 5W to what I seem to remember him posting once in the JT65-HF Google group is a Hamstick on a mag mount stuck to the roof of his shed. Thank you Joe for the contact and for the fantastic JT65-HF software!
JT65 is addictive. It's also a very relaxing way to make QSOs. It's ideal for me at the moment because my eyes tire very easily. I end up with blurred or double vision if I read or stare at the computer screen for too long so modes like PSK31 aren't really a good idea. Thanks to the JT65-HF add-on JT-Alert an alarm sounds if a station I haven't worked before calls CQ and another sound wakes me up if a station replies to me. This means that I can look out the window or something and only need look at the screen when I have something to do. The print in the JT65-HF program window is nice and big too.
Listening on 28.076 I heard some strange noises which I eventually realized were FM transmissions being received in SSB mode. CBers transmitting out of band I presume.
I don't suppose many CBers read this blog but come on, guys. It's none of my business if you choose to operate illegally but if you do, please stay below 28MHz. You may not hear our weak JT65 signals with your FM radios but we sure as hell can hear you.
Update: Just worked Joe "The Man" W6CQZ/4 in Florida. He was running 5W to what I seem to remember him posting once in the JT65-HF Google group is a Hamstick on a mag mount stuck to the roof of his shed. Thank you Joe for the contact and for the fantastic JT65-HF software!
Sunday, October 02, 2011
Nothing but whispers
In the last few days several people have posted in their blogs or in forums that conditions on 10m have been great. Either I have been listening at the wrong times or this QTH is as bad on the higher HF bands as it is on VHF. When I have tuned across the 10m band I have found only one or two signals strong enough to be heard above the S4 noise level I now have on this band and none loud enough to work.
It's probably my QTH. Last year when Olga was away in Ukraine I operated from the car with my QRP K2 and an MP-1 antenna on a mag mount and from just a few miles away but overlooking the coast I worked DX on 15 and 17m that I had never heard from home. Unfortunately going mobile is no longer an option as I am not allowed to drive due to my illness.
Something must be working right though. Most of the day I have been running WSPR on 10m with 5 watts to the dipole and my signal was spotted on 5 continents. It's good, but it isn't the same as having an actual conversation. You can see why my interest these days is turning more towards things like EchoLink.
It's probably my QTH. Last year when Olga was away in Ukraine I operated from the car with my QRP K2 and an MP-1 antenna on a mag mount and from just a few miles away but overlooking the coast I worked DX on 15 and 17m that I had never heard from home. Unfortunately going mobile is no longer an option as I am not allowed to drive due to my illness.
Something must be working right though. Most of the day I have been running WSPR on 10m with 5 watts to the dipole and my signal was spotted on 5 continents. It's good, but it isn't the same as having an actual conversation. You can see why my interest these days is turning more towards things like EchoLink.
Thursday, September 29, 2011
EchoLink or D-Star?
Over the last few days I have been running my EchoLink node #3098 connected into the IRELAND conference server. As I've been feeling a bit tired and lethargic recently it has been a way to pass the time listening to QSOs and making the occasional contact.
Apart from IRELAND there seems to be nowhere else on the EchoLink network where there is enough activity that you can guarantee something to listen to or that someone will reply if you call CQ. I know this is like talking of selling your soul to the Devil but would D-Star, which I have never experienced but which I gather has something called "reflectors", be any better from the point of view of making contacts with hams around the globe using a handheld?
Apart from IRELAND there seems to be nowhere else on the EchoLink network where there is enough activity that you can guarantee something to listen to or that someone will reply if you call CQ. I know this is like talking of selling your soul to the Devil but would D-Star, which I have never experienced but which I gather has something called "reflectors", be any better from the point of view of making contacts with hams around the globe using a handheld?
Tuesday, September 27, 2011
Yet another fake Diamond antenna
I ordered a Nagoya NA-771 antenna on eBay. I was impressed with the shorter NA-701 and wanted something with a bit more gain that was not poke-you-in-the-eye long. The NA-771 had mostly good reviews on eHam.
I ordered from an eBay seller that shipped from the UK. The price was £4.99. When it arrived, I found the packaging and the antenna itself claimed to be a Diamond RH-771 not a Nagoya NA-771.
But this is clearly another fake Diamond. The lettering is white whereas the real Diamond product is lettered in blue. The lettering also contains nonsense. It claims "144/430 MHz & VDE BAND HECEMNG COVERAGE JAPAN." Eh??? Perhaps it was supposed to say wide band general coverage? And the antenna is only 36cm long whereas the real RH-771 (and the NA-771) are supposed to be 39-40cm long.
None of this would matter if the antenna was any use, but in fact its resonant frequency is just below 120MHz. At 145MHz the SWR is more than 4 to 1 and it radiates a poorer signal than the shorter Nagoya NA-701 antenna.
Anyone want an air band antenna? Yours for a fiver. And can anyone recommend a seller that has the genuine Nagoya NA-771?
I ordered from an eBay seller that shipped from the UK. The price was £4.99. When it arrived, I found the packaging and the antenna itself claimed to be a Diamond RH-771 not a Nagoya NA-771.
But this is clearly another fake Diamond. The lettering is white whereas the real Diamond product is lettered in blue. The lettering also contains nonsense. It claims "144/430 MHz & VDE BAND HECEMNG COVERAGE JAPAN." Eh??? Perhaps it was supposed to say wide band general coverage? And the antenna is only 36cm long whereas the real RH-771 (and the NA-771) are supposed to be 39-40cm long.
None of this would matter if the antenna was any use, but in fact its resonant frequency is just below 120MHz. At 145MHz the SWR is more than 4 to 1 and it radiates a poorer signal than the shorter Nagoya NA-701 antenna.
Anyone want an air band antenna? Yours for a fiver. And can anyone recommend a seller that has the genuine Nagoya NA-771?
Tuesday, September 20, 2011
Waste of money
Yesterday I received a personally addressed letter from our cash-strapped radio society, the RSGB. What had motivated them to write to me? Apparently it was to tell me the annual subscription is to rise to £47 a year - the first increase since 2006 - and to ask if I would donate to the Spectrum Defence Fund - which I already have, once, and a lot of good that did - or the Radio Communications Foundation.
Why could this letter not have been put in the same mailer as RadCom, the monthly magazine that all members receive, or even published in the magazine itself? Why did this even merit a letter, rather than a page of the magazine, in the first place?
A few months ago I read that the RSGB was to use a bequest from a silent key member to employ a professional fund raiser. This, presumably, is the result. What a waste of money.
Why could this letter not have been put in the same mailer as RadCom, the monthly magazine that all members receive, or even published in the magazine itself? Why did this even merit a letter, rather than a page of the magazine, in the first place?
A few months ago I read that the RSGB was to use a bequest from a silent key member to employ a professional fund raiser. This, presumably, is the result. What a waste of money.
Sunday, September 18, 2011
UV-3R programming software
A new programming software has been released for the Baofeng UV-3R. At the moment you can download it here. I used BitZipper to open the rar file.
This software is claimed to be for the UV-3R MkII with the dual frequency display but it works with my MkI as well. I took the precaution of reading from the radio before modifying and writing anything: some people who didn't do that with the old program experienced problems.
The new program is easy to use. Interestingly, it has two options for frequency range, one of which limits the range to the ham bands 144-146MHz and 430-440MHz. I assume that is to get approval in some countries that don't allow radios that can transmit out of band. There is also a column called Name for each channel, though I couldn't type anything in there. Perhaps a newer model will allow you to have channel names as well.
I discovered a bug with setting the priority channel, though it's kind of hard to explain. You choose the priority channel from a drop-down list of channels that have been used. If you haven't used all the channels between channel 1 and the priority channel then the radio will check the channel corresponding to the position in the list of the one you selected instead of that actual channel number. I wanted to make channel 20 the priority channel but the radio started checking channel 14 because 20 was the 14th filled channel in
the list! To use channel 20 as the priority channel I had to select channel 26, which was the 20th one in the list.
I don't know what would have happened if the channel I'd picked was one that didn't have a frequency programmed into it - and I'm not going to risk finding out!
I ought to mention that the cross-platform multi-radio supporting memory management software CHIRP supports the UV-3R as well. Not sure about the UV-3R MkII though.
This software is claimed to be for the UV-3R MkII with the dual frequency display but it works with my MkI as well. I took the precaution of reading from the radio before modifying and writing anything: some people who didn't do that with the old program experienced problems.
The new program is easy to use. Interestingly, it has two options for frequency range, one of which limits the range to the ham bands 144-146MHz and 430-440MHz. I assume that is to get approval in some countries that don't allow radios that can transmit out of band. There is also a column called Name for each channel, though I couldn't type anything in there. Perhaps a newer model will allow you to have channel names as well.
I discovered a bug with setting the priority channel, though it's kind of hard to explain. You choose the priority channel from a drop-down list of channels that have been used. If you haven't used all the channels between channel 1 and the priority channel then the radio will check the channel corresponding to the position in the list of the one you selected instead of that actual channel number. I wanted to make channel 20 the priority channel but the radio started checking channel 14 because 20 was the 14th filled channel in
the list! To use channel 20 as the priority channel I had to select channel 26, which was the 20th one in the list.
I don't know what would have happened if the channel I'd picked was one that didn't have a frequency programmed into it - and I'm not going to risk finding out!
I ought to mention that the cross-platform multi-radio supporting memory management software CHIRP supports the UV-3R as well. Not sure about the UV-3R MkII though.
Tuesday, September 13, 2011
VK5 with V4
Looking for something to pique my interest enough to overcome my lethargy I decided to have another look at the V4 Chat digital mode. I tried it first at the end of last year and made one contact with it, but the alpha software was a bit flaky, then the developer Rick KN6KB had a bereavement and nothing happened for a while so I forgot all about it.
What attracted my interest was discovering that the ARQ mode had now been implemented. V4 Chat supports two conversation modes: Forward Error Correction (FEC) in which the data is sent with a lot of checks and redundancy so many receiving errors can be corrected but you have one chance of getting it correctly, and Automatic Repeat reQuest (ARQ) in which the receiver can request a repeat if a transmission is received with errors. Using ARQ a receiver can repeatedly request a repeat (up to a limit) so even if conditions are marginal a QSO is possible as long as propagation is adequate for short periods of time. Under the same conditions conventional (non ARQ) digital modes would print so much garbage that a contact would not be possible. People who own expensive SCS modems like to boast about how Pactor gets through under difficult conditions but V4 ARQ offers the same kind of performance and requires only your PC and a bit of open source donationware.
I re-subscribed to the V4Protocol Yahoo Group (which is where you can get the software from), downloaded and installed the latest version. Then I set my K3 to 14.073MHz (which is the 20m "calling frequency" for experimental narrow data modes) and waited. After a while I heard the sound of V4 ARQ bursts, and found that VK5PO was in QSO. I saw him disconnect from the other station and sent a CQ. He then connected with me and we had (just about) a QSO.
Signals were marginal both ways and I had to crank the K3 up to 50W to help John copy me but over about 10 minutes names and signal reports were exchanged. One of the nice things about the ARQ mode is that when the text prints up you know the other station has received it error free.
OK, it wasn't much of a chat, but ignoring WSPR spots I have only ever made one contact with Australia before and that was using JT65A which is not a keyboard chat mode. I was pretty chuffed to exchange words with a ham 16,000km away using my stealth radio station!
I think I'll be spending a lot more time trying out V4 Chat digital mode and I hope you will too because the more people use it the more contacts we can all make. The V4 signal is 200Hz wide so if 14.073 (or 21.073) is busy move up in 250Hz increments to avoid QRMing someone else's QSO.
What attracted my interest was discovering that the ARQ mode had now been implemented. V4 Chat supports two conversation modes: Forward Error Correction (FEC) in which the data is sent with a lot of checks and redundancy so many receiving errors can be corrected but you have one chance of getting it correctly, and Automatic Repeat reQuest (ARQ) in which the receiver can request a repeat if a transmission is received with errors. Using ARQ a receiver can repeatedly request a repeat (up to a limit) so even if conditions are marginal a QSO is possible as long as propagation is adequate for short periods of time. Under the same conditions conventional (non ARQ) digital modes would print so much garbage that a contact would not be possible. People who own expensive SCS modems like to boast about how Pactor gets through under difficult conditions but V4 ARQ offers the same kind of performance and requires only your PC and a bit of open source donationware.
I re-subscribed to the V4Protocol Yahoo Group (which is where you can get the software from), downloaded and installed the latest version. Then I set my K3 to 14.073MHz (which is the 20m "calling frequency" for experimental narrow data modes) and waited. After a while I heard the sound of V4 ARQ bursts, and found that VK5PO was in QSO. I saw him disconnect from the other station and sent a CQ. He then connected with me and we had (just about) a QSO.
Signals were marginal both ways and I had to crank the K3 up to 50W to help John copy me but over about 10 minutes names and signal reports were exchanged. One of the nice things about the ARQ mode is that when the text prints up you know the other station has received it error free.
OK, it wasn't much of a chat, but ignoring WSPR spots I have only ever made one contact with Australia before and that was using JT65A which is not a keyboard chat mode. I was pretty chuffed to exchange words with a ham 16,000km away using my stealth radio station!
I think I'll be spending a lot more time trying out V4 Chat digital mode and I hope you will too because the more people use it the more contacts we can all make. The V4 signal is 200Hz wide so if 14.073 (or 21.073) is busy move up in 250Hz increments to avoid QRMing someone else's QSO.
Sunday, September 11, 2011
9/11
Everyone remembers what they were doing when they found out about the 9/11 attacks. I remember it because I had a bad migraine that day, rather like the one that turned out to be a harbinger of my brain tumour. I switched off the computer, drew the curtains in the bedroom, lay down on the bed and switched on the radio. Instead of the expected classical music there were voices talking about a plane that had crashed into the World Trade Centre. For a few minutes I lay there thinking I was listening to some "mockumentary" radio play like the famous Orson Welles "aliens have handed" spoof. But something told me that wasn't right, so I went downstairs, turned on the TV and saw that this was all too real.
Today I hope against hope that we get through this anniversary day without another terrorist attack attempt. I just don't understand why anyone would want to give up their life, and end the lives of other innocent people, for any "cause". One thing being diagnosed with an incurable brain tumour has made me realize is that life is too short to waste getting angry about things you don't agree with.. Wouldn't the world be a better place if we could all banish negative thoughts, focus on enjoying life as best we can with those we love, and make peace even with our enemies?
Today I hope against hope that we get through this anniversary day without another terrorist attack attempt. I just don't understand why anyone would want to give up their life, and end the lives of other innocent people, for any "cause". One thing being diagnosed with an incurable brain tumour has made me realize is that life is too short to waste getting angry about things you don't agree with.. Wouldn't the world be a better place if we could all banish negative thoughts, focus on enjoying life as best we can with those we love, and make peace even with our enemies?
Tuesday, September 06, 2011
Two new 2m repeater channels
According to the UK repeaters website, two new 2m repeater channels have been internationally agreed:
Looks like we dinosaurs who still insist on calling the calling channel S20 are going to have to give up QSYing to S23!
- 144.9750MHz input / 145.5750MHz output (RV46)
- 144.9875MHz input / 145.5875MHz output (RV47)
Looks like we dinosaurs who still insist on calling the calling channel S20 are going to have to give up QSYing to S23!
Wednesday, August 24, 2011
WOTA Activity Weekend
Next weekend 27 - 29 August is the Wainwrights On The Air Activity Weekend. Many radio amateurs are planning to activate Wainwright summits over this three day Bank Holiday weekend - see the list of currently planned activations here. If you will be in or around the Lake District during this period then be prepared for a lot of activity on all the VHF and UHF bands.
The team that has taken over the running of WOTA following my illness is doing a great job and has come up with several new ideas. There will be a special activation of the summit of Latrigg, one of the lower summits to the north of Keswick, on the Bank Holiday Monday. It's an easy walk for most people so if you will be in Keswick on that day why not stroll up after lunch and meet some of the team? If you are thinking about a family day out then Keswick Agricultural Show is being held on the same day and is always worth a visit.
I hope to be on the summit of Latrigg myself on Monday afternoon. The team has obtained permission to take a 4x4 on to the fell so I can have a ride to the top and won't have to climb. I am looking forward to the opportunity to be on a summit again but whether I am able to go will depend on how I feel on the day and, of course, the ever unpredictable Cumbrian weather. I will be well into the chemotherapy regime by then which depresses the immune system so getting cold or wet would not be a good idea at this time.
The team that has taken over the running of WOTA following my illness is doing a great job and has come up with several new ideas. There will be a special activation of the summit of Latrigg, one of the lower summits to the north of Keswick, on the Bank Holiday Monday. It's an easy walk for most people so if you will be in Keswick on that day why not stroll up after lunch and meet some of the team? If you are thinking about a family day out then Keswick Agricultural Show is being held on the same day and is always worth a visit.
I hope to be on the summit of Latrigg myself on Monday afternoon. The team has obtained permission to take a 4x4 on to the fell so I can have a ride to the top and won't have to climb. I am looking forward to the opportunity to be on a summit again but whether I am able to go will depend on how I feel on the day and, of course, the ever unpredictable Cumbrian weather. I will be well into the chemotherapy regime by then which depresses the immune system so getting cold or wet would not be a good idea at this time.
Tuesday, August 23, 2011
iGate QRT again
The G4ILO APRS iGate is off the air again. My Android smartphone is on its way back to Motorola for repair so for the time being I need to use the Windows Mobile as a phone again.
I'll also be running APRSISCE on it as G4ILO-SP while travelling to and from radiotherapy treatment in Carlisle. That is so that Olga can look at aprs.fi and see when I am about to return home. As I am using the volunteer hospital car service, time and route can be somewhat variable. APRS does have its practical uses...
I'll also be running APRSISCE on it as G4ILO-SP while travelling to and from radiotherapy treatment in Carlisle. That is so that Olga can look at aprs.fi and see when I am about to return home. As I am using the volunteer hospital car service, time and route can be somewhat variable. APRS does have its practical uses...
Sunday, August 21, 2011
VK on a whip antenna
The amazing power of the WSPR mode to enable weak signals to be received over long distances was demonstrated conclusively when my 2 watt signals, transmitted into a 1.3m long telescopic whip antenna from inside the G4ILO shack,were received in Australia and the USA, not once but several times with SNR reports of up to -19dB.
These spots were not achieved using a hand held radio as they occurred early in the morning when I was asleep. But they were made using a home made portable 30m whip antenna that I designed to be used with the VCXO-AXE portable WSPR transmitter I recently built. Here is a picture of the antenna taken during the tests.
The antenna consists of an L-match mounted in a small plastic project box, with BNC sockets for the transmitter and the whip antenna.
The constructional details can be gleaned from this internal view here. Click the image to see a much larger version.
The loading coil consists of about 46 turns of 28SWG wire on a T80-6 toroid. The matching capacitor is a 4 - 40pF trimmer. The number of turns was determined empirically (i.e. using trial and error) so don't ask me for details of how to make one for other bands. There may be formulas for calculating things like that but I don't know them.
It would have been difficult to make this antenna without an antenna analyzer like my RigExpert AA-200 which displays the SWR across a range of frequencies graphically. With my first attempt at the inductor it was possible to obtain an SWR null at 10.140MHz but it was rather a broad dip and the minimum was around 3:1. However at lower frequencies I saw that I was able to obtain a much deeper, sharper null. This made it clear that what I needed to do was remove some turns until the deep, sharp null was at the frequency I wanted. A deep null indicates higher Q and therefore better efficiency.
You can see the SWR curve of the final version below.
Note, however, that this was taken inside the shack in the test position where reflections spoiled the SWR and broadened the dip. When measured out of doors the SWR curve dipped deeper and was narrower as long as I stood clear of the antenna. (It was interesting to note how the SWR was affected even if I was a metre away from the telescopic whip. This suggests efficiency would be adversely affected when used in true hand held fashion.)
A good ground or quarter wave counterpoise wire is needed with this antenna. The resonant frequency is affected by the ground system used as well as the length of the whip and the position of the trimmer. If you don't want to take an antenna analyzer to the field to check and tune the antenna before operation you should use the same counterpoise. So it would be advisable to pair the counterpoise with the antenna.
Further tests would be useful to determine the extent to which a good match is reproducible in different locations using the same whip length and counterpoise without retuning.
In case retuning is needed I added an access hole for the tuning trimmer. The resonant frequency can also be changed (increased) by shortening the telescopic whip a section or two.
This has been an interesting project. As a result of it I now have a completely portable, pocketable, battery powered system capable of sending a radio signal half way round the world, and I have developed a useful monoband 30m antenna.
These spots were not achieved using a hand held radio as they occurred early in the morning when I was asleep. But they were made using a home made portable 30m whip antenna that I designed to be used with the VCXO-AXE portable WSPR transmitter I recently built. Here is a picture of the antenna taken during the tests.
The antenna consists of an L-match mounted in a small plastic project box, with BNC sockets for the transmitter and the whip antenna.
The constructional details can be gleaned from this internal view here. Click the image to see a much larger version.
The loading coil consists of about 46 turns of 28SWG wire on a T80-6 toroid. The matching capacitor is a 4 - 40pF trimmer. The number of turns was determined empirically (i.e. using trial and error) so don't ask me for details of how to make one for other bands. There may be formulas for calculating things like that but I don't know them.
It would have been difficult to make this antenna without an antenna analyzer like my RigExpert AA-200 which displays the SWR across a range of frequencies graphically. With my first attempt at the inductor it was possible to obtain an SWR null at 10.140MHz but it was rather a broad dip and the minimum was around 3:1. However at lower frequencies I saw that I was able to obtain a much deeper, sharper null. This made it clear that what I needed to do was remove some turns until the deep, sharp null was at the frequency I wanted. A deep null indicates higher Q and therefore better efficiency.
You can see the SWR curve of the final version below.
Note, however, that this was taken inside the shack in the test position where reflections spoiled the SWR and broadened the dip. When measured out of doors the SWR curve dipped deeper and was narrower as long as I stood clear of the antenna. (It was interesting to note how the SWR was affected even if I was a metre away from the telescopic whip. This suggests efficiency would be adversely affected when used in true hand held fashion.)
A good ground or quarter wave counterpoise wire is needed with this antenna. The resonant frequency is affected by the ground system used as well as the length of the whip and the position of the trimmer. If you don't want to take an antenna analyzer to the field to check and tune the antenna before operation you should use the same counterpoise. So it would be advisable to pair the counterpoise with the antenna.
Further tests would be useful to determine the extent to which a good match is reproducible in different locations using the same whip length and counterpoise without retuning.
In case retuning is needed I added an access hole for the tuning trimmer. The resonant frequency can also be changed (increased) by shortening the telescopic whip a section or two.
This has been an interesting project. As a result of it I now have a completely portable, pocketable, battery powered system capable of sending a radio signal half way round the world, and I have developed a useful monoband 30m antenna.
Saturday, August 20, 2011
Motorola Millstone
This weekend I had planned to write about my Android smartphone, a Motorola Milestone 2, which I bought in early July soon after I came out of hospital. It was a fantastic phone with a big, clear screen and a really usable slide-out keyboard. It became my main method of electronic communication. The Android user interface is great - far, far superior to Windows Mobile. It is well integrated with Gmail as you would expect and it has an excellent web browser that can display almost any website, unlike the IE browser in Windows Mobile which is just a piece of s***. I was also intending to write about an Android APRS application called U2APRS. Unfortunately, last night my Milestone turned into a brick.
The one thing I hadn't got round to doing was install a good app to read the various blogs that I follow. Blogger Dashboard is one of the few sites that doesn't work well in the Android browser. I decided to install Feedly, found that I liked it, and spent some time going through all the blogs marking all the posts as read. Having done that I was trying to figure out how to get back to the list of blogs now that there were no new posts when the screen froze and refused to respond to touch input.
Thinking that this was just a software crash, I pulled the battery. But when the phone started up again the screen still refused to respond to finger movements. And now I couldn't get past the lock. This situation persisted after several attempts.
Time to go online. A Google search revealed that problems with the Motorola Milestone 2 touch screen were not uncommon and that the only diagnostic to try was to perform a factory reset to make sure that the trouble was not due to a software glitch. This would, of course, remove all my apps and settings. But there was no alternative. Except that the instructions for performing a hard reset - press and hold the Camera button while powering up the phone - didn't work. Every time, the phone booted into its normal screen, which was still locked.
After wasting quite a lot of time making several attempts at this I found another forum post that suggested holding the X key on the keyboard whilst powering on the phone. This got me a step nearer to where I was trying to be - a screen with a warning triangle and an Android icon on it - but the instructions to bring up the menu - press and hold the Volume Up button and then the Camera button - did nothing. Again, a lot of time was wasted trying this several times, including different permutations of pressing and holding, and trying both of the Volume buttons since I couldn't be sure which was Up and which was Down, to no avail. Deep frustration was setting in.
Olga found a forum post which suggested that pressing the keyboard Search button from the Android warning screen would bring up the reset menu. That didn't work either. Then she found another one that said to use the the @ key. At last, the menu! I was finally able to format the system and wipe all my apps and data. When the phone rebooted it entered the initial configuration sequence, asking what language I wanted it to use. Which I was unable to select because the touch screen still didn't work.
So my Milestone is currently as much use as a lump of rock. I'm missing it already. It will probably take several days to send it for repair and have it returned, which I can't even start to do until Monday. But I'd rather do without a phone than go back to Windows Mobile, which may be a very good platform for running apps but is absolutely loathsome as a telephone and is totally useless for Gmail.
Deep frustration. Not to mention irritation over the valuable time I'll have to spend reinstalling and reconfiguring everything once it's back. And to add to my annoyance I've lost U2APRS because the developer JA7UDE's web site has been offline for the last couple of weeks for reasons unknown and there is no longer any way to obtain it.
I'm not a happy bunny.
The one thing I hadn't got round to doing was install a good app to read the various blogs that I follow. Blogger Dashboard is one of the few sites that doesn't work well in the Android browser. I decided to install Feedly, found that I liked it, and spent some time going through all the blogs marking all the posts as read. Having done that I was trying to figure out how to get back to the list of blogs now that there were no new posts when the screen froze and refused to respond to touch input.
Thinking that this was just a software crash, I pulled the battery. But when the phone started up again the screen still refused to respond to finger movements. And now I couldn't get past the lock. This situation persisted after several attempts.
Time to go online. A Google search revealed that problems with the Motorola Milestone 2 touch screen were not uncommon and that the only diagnostic to try was to perform a factory reset to make sure that the trouble was not due to a software glitch. This would, of course, remove all my apps and settings. But there was no alternative. Except that the instructions for performing a hard reset - press and hold the Camera button while powering up the phone - didn't work. Every time, the phone booted into its normal screen, which was still locked.
After wasting quite a lot of time making several attempts at this I found another forum post that suggested holding the X key on the keyboard whilst powering on the phone. This got me a step nearer to where I was trying to be - a screen with a warning triangle and an Android icon on it - but the instructions to bring up the menu - press and hold the Volume Up button and then the Camera button - did nothing. Again, a lot of time was wasted trying this several times, including different permutations of pressing and holding, and trying both of the Volume buttons since I couldn't be sure which was Up and which was Down, to no avail. Deep frustration was setting in.
Olga found a forum post which suggested that pressing the keyboard Search button from the Android warning screen would bring up the reset menu. That didn't work either. Then she found another one that said to use the the @ key. At last, the menu! I was finally able to format the system and wipe all my apps and data. When the phone rebooted it entered the initial configuration sequence, asking what language I wanted it to use. Which I was unable to select because the touch screen still didn't work.
So my Milestone is currently as much use as a lump of rock. I'm missing it already. It will probably take several days to send it for repair and have it returned, which I can't even start to do until Monday. But I'd rather do without a phone than go back to Windows Mobile, which may be a very good platform for running apps but is absolutely loathsome as a telephone and is totally useless for Gmail.
Deep frustration. Not to mention irritation over the valuable time I'll have to spend reinstalling and reconfiguring everything once it's back. And to add to my annoyance I've lost U2APRS because the developer JA7UDE's web site has been offline for the last couple of weeks for reasons unknown and there is no longer any way to obtain it.
I'm not a happy bunny.
Friday, August 19, 2011
The WSPR Boss
I ordered a GymBoss workout timer - not as a keep-fit aid but as a timer controller for the VCXO-AXE WSPR transmitter.
W5OLF doesn't provide a lot of detail on how to modify the GymBoss but it isn't difficult - especially if you don't have fuzzy vision, shaky hands and fingers the size of Cumberland sausages. As I have all of those things I experienced an initial panic as I thought I was more likely to break the GymBoss than successfully modify it. Consequently I neglected to take any pictures of the process as I just wanted to get the job done without additional distractions.
Two screws secure the base of the GymBoss. Lift this away carefully as it is secured to the PCB by two short, flimsy and not particularly well soldered wires from the battery compartment. Once the base is clear you can remove two more smaller screws which hold the PCB to the front panel. At this point the pushbuttons will fall out - hopefully you will have made a note of exactly how they were installed so you can put it back together without too much difficulty.
The LCD display rests on the back of the PCB and can be hinged clear to reveal the bottom of the board. The beeper which has to be removed has two connections. The easiest way to remove it I found was just to grasp it between finger and thumb whilst applying the soldering iron to each of the two pins in turn, pushing the board away a bit at a time with another finger until it was clear.
I then soldered a thin screened cable to the two holes that had been used by the beeper. Using my ohmmeter I identified one hole that was at ground potential, so the braid was soldered to that one. I made a small hole in the case near to the "reboot" switch hole to allow the cable to exit. Then I carefully reassembled the GymBoss.
I attached the beeper to the end of the screened cable to check that the GymBoss still worked. To my relief, it did. I then attached a plug to match up with the socket I had already installed for P2 when I built the VCXO-AXE. The braid goes to the ground connection and the beeper signal to the Start pin. I then checked the transmitter with my power meter / dummy load to ensure that the GymBoss was turning it on at the interval I had chosen.
The timer works well and has maintained adequate accuracy for the 12 hours or so it has been running so far. It will start up to 99 transmit cycles at any interval you specify, so you can't have it run indefinitely if you leave it unattended.
As of right now I am running a transmit cycle every 8 minutes using 2 watts into a home-made loaded whip antenna inside the shack using the central heating system as a ground. This has received plenty of spots from Europe and a few overnight from W3HH in the USA which I would not have been able to obtain if I had to key the transmitter manually.
Although manual keying is simple and fine for occasional use, I'm in no doubt that the timer makes the WCXO-AXE much more useful.
W5OLF doesn't provide a lot of detail on how to modify the GymBoss but it isn't difficult - especially if you don't have fuzzy vision, shaky hands and fingers the size of Cumberland sausages. As I have all of those things I experienced an initial panic as I thought I was more likely to break the GymBoss than successfully modify it. Consequently I neglected to take any pictures of the process as I just wanted to get the job done without additional distractions.
Two screws secure the base of the GymBoss. Lift this away carefully as it is secured to the PCB by two short, flimsy and not particularly well soldered wires from the battery compartment. Once the base is clear you can remove two more smaller screws which hold the PCB to the front panel. At this point the pushbuttons will fall out - hopefully you will have made a note of exactly how they were installed so you can put it back together without too much difficulty.
The LCD display rests on the back of the PCB and can be hinged clear to reveal the bottom of the board. The beeper which has to be removed has two connections. The easiest way to remove it I found was just to grasp it between finger and thumb whilst applying the soldering iron to each of the two pins in turn, pushing the board away a bit at a time with another finger until it was clear.
I then soldered a thin screened cable to the two holes that had been used by the beeper. Using my ohmmeter I identified one hole that was at ground potential, so the braid was soldered to that one. I made a small hole in the case near to the "reboot" switch hole to allow the cable to exit. Then I carefully reassembled the GymBoss.
I attached the beeper to the end of the screened cable to check that the GymBoss still worked. To my relief, it did. I then attached a plug to match up with the socket I had already installed for P2 when I built the VCXO-AXE. The braid goes to the ground connection and the beeper signal to the Start pin. I then checked the transmitter with my power meter / dummy load to ensure that the GymBoss was turning it on at the interval I had chosen.
The timer works well and has maintained adequate accuracy for the 12 hours or so it has been running so far. It will start up to 99 transmit cycles at any interval you specify, so you can't have it run indefinitely if you leave it unattended.
As of right now I am running a transmit cycle every 8 minutes using 2 watts into a home-made loaded whip antenna inside the shack using the central heating system as a ground. This has received plenty of spots from Europe and a few overnight from W3HH in the USA which I would not have been able to obtain if I had to key the transmitter manually.
Although manual keying is simple and fine for occasional use, I'm in no doubt that the timer makes the WCXO-AXE much more useful.
Thursday, August 18, 2011
5V noise generator
An increasing number of electronic devices can be powered or charged from a USB socket. To charge them independently of the computer they usually come with a small switched mode wall-wart. Finding enough wall sockets for these broadband noise generators - in addition to all the wall-warts that already exist in the ham shack - can be a challenge. It would be nice if ham radio power supplies had a few 5V DC outputs.
When I started using my HTC Touch Pro smartphone as an APRS iGate I wanted to avoid using the HTC charger as I knew it created a few warblies on some of the HF bands. I wondered if I could power the phone from the shack supply instead. In the junk box I found a car charger for an old satnav that had the same mini-USB plug and fitted the cigar lighter type socket on my Diamond GSV3000 power supply. That seemed to do the job very well and didn't appear to generate any RF noise (though the noise level here is now so high that the incremental difference made by one more switched mode device is hard to detect.) The only annoying thing about it was that it sticks rather a long way out of the front panel of the GSV3000, which is a bit of a nuisance on my narrow operating desk.
My next thought was that it would be nice to have more than one 5V outlet, perhaps in USB format, to occasionally charge other devices without requiring the computer to be on or plugging in another wall wart. Browsing eBay I saw a Griffin Dual Power USB Car Charger. This would give me two 5V USB outlets. And it was also designed to be flush with the top of the cigar lighter socket so it would look like an integral part of the GSV3000 once installed.
When it arrived I was quickly disappointed. As soon as I plugged a USB cable into one of the outlets, even with no load attached, broadband HF noise jumped up about 3 S-points. The device also got surprisingly hot even though nothing was drawing any current from it. I guess I should have anticipated that a device that size would use some kind of switching regulator and that this might result in noise. For the typical user wanting to power or charge two USB devices from their car, the noise is unlikely to be a problem. So I guess this particular solution to eliminating wall-warts is a non-starter.
When I started using my HTC Touch Pro smartphone as an APRS iGate I wanted to avoid using the HTC charger as I knew it created a few warblies on some of the HF bands. I wondered if I could power the phone from the shack supply instead. In the junk box I found a car charger for an old satnav that had the same mini-USB plug and fitted the cigar lighter type socket on my Diamond GSV3000 power supply. That seemed to do the job very well and didn't appear to generate any RF noise (though the noise level here is now so high that the incremental difference made by one more switched mode device is hard to detect.) The only annoying thing about it was that it sticks rather a long way out of the front panel of the GSV3000, which is a bit of a nuisance on my narrow operating desk.
My next thought was that it would be nice to have more than one 5V outlet, perhaps in USB format, to occasionally charge other devices without requiring the computer to be on or plugging in another wall wart. Browsing eBay I saw a Griffin Dual Power USB Car Charger. This would give me two 5V USB outlets. And it was also designed to be flush with the top of the cigar lighter socket so it would look like an integral part of the GSV3000 once installed.
When it arrived I was quickly disappointed. As soon as I plugged a USB cable into one of the outlets, even with no load attached, broadband HF noise jumped up about 3 S-points. The device also got surprisingly hot even though nothing was drawing any current from it. I guess I should have anticipated that a device that size would use some kind of switching regulator and that this might result in noise. For the typical user wanting to power or charge two USB devices from their car, the noise is unlikely to be a problem. So I guess this particular solution to eliminating wall-warts is a non-starter.
Wednesday, August 17, 2011
Get the drift
Don't you hate it when you build a project, it works, then you put it into a case and find that it is no longer working as well as it was?
I built the VCXO-AXE 30m WSPR tramsmitter and it worked perfectly. I then put it in a nice case and began testing it with various portable antennas. At the start I received several spots of my transmissions but after a while the spots became few and far between until hours would pass without any report of my signal.
At first I thought this was due to poor conditions or the fact that the antennas I was testing were inefficient. Eventually I investigated by putting the TX on a dummy load and listening for it with my K3. I found that although I had initially set the VCXO-AXE up to transmit 40Hz above the bottom of the 200Hz wide WSPR band, the frequency had drifted low so that my transmission was now right on the bottom edge and possibly below it on many receivers since I couldn't guarantee my K3 readout was dead accurate.
It was easy enough to set the transmit frequency back to what I wanted it to be. But I still didn't receive any spots of my signals.
I looked a bit closer and noticed that although my signal started off as a horizontal line for about the first two-thirds of the transmit cycle, the last third curved down a little. The WSPR software was reporting a drift of -3Hz, which was typically what I had been receiving from those stations that had spotted me. There is a thread in the forum section of the WSPR website which suggests that few signals which drift more than 3Hz are reported. So it seemed probable that drift of my signal was preventing it from being spotted.
Before I put the transmitter into a box the frequency had been perfectly stable after the initial warm-up period. So it was obvious what the trouble was. I drilled a small grid of ventilation holes in the back of the case just above the PA FET and attempted to increase the thermal inertia of the VCXO chip by placing a blob of Blu-Tack over the top of it. This made not the slightest difference. I was still getting -3Hz drift reported on the decodes of my transmissions.
After further investigation I found that the worst heat generating component was in fact the 5V voltage regulator, which also happens to be fairly close to the VCXO chip. So I drilled a further set of holes above that. I also fabricated a heat shield from a piece of cardboard sandwiched between the PCB and the back of the case with Blu-Tack to try to induce most of the heat to go out through the holes instead of heading in the direction of the oscillator. This did make an improvement. I'm now mostly seeing reports of -1Hz drift or even none at all. And I'm getting a lot more spots of my WSPR transmissions!
I built the VCXO-AXE 30m WSPR tramsmitter and it worked perfectly. I then put it in a nice case and began testing it with various portable antennas. At the start I received several spots of my transmissions but after a while the spots became few and far between until hours would pass without any report of my signal.
At first I thought this was due to poor conditions or the fact that the antennas I was testing were inefficient. Eventually I investigated by putting the TX on a dummy load and listening for it with my K3. I found that although I had initially set the VCXO-AXE up to transmit 40Hz above the bottom of the 200Hz wide WSPR band, the frequency had drifted low so that my transmission was now right on the bottom edge and possibly below it on many receivers since I couldn't guarantee my K3 readout was dead accurate.
It was easy enough to set the transmit frequency back to what I wanted it to be. But I still didn't receive any spots of my signals.
I looked a bit closer and noticed that although my signal started off as a horizontal line for about the first two-thirds of the transmit cycle, the last third curved down a little. The WSPR software was reporting a drift of -3Hz, which was typically what I had been receiving from those stations that had spotted me. There is a thread in the forum section of the WSPR website which suggests that few signals which drift more than 3Hz are reported. So it seemed probable that drift of my signal was preventing it from being spotted.
Before I put the transmitter into a box the frequency had been perfectly stable after the initial warm-up period. So it was obvious what the trouble was. I drilled a small grid of ventilation holes in the back of the case just above the PA FET and attempted to increase the thermal inertia of the VCXO chip by placing a blob of Blu-Tack over the top of it. This made not the slightest difference. I was still getting -3Hz drift reported on the decodes of my transmissions.
After further investigation I found that the worst heat generating component was in fact the 5V voltage regulator, which also happens to be fairly close to the VCXO chip. So I drilled a further set of holes above that. I also fabricated a heat shield from a piece of cardboard sandwiched between the PCB and the back of the case with Blu-Tack to try to induce most of the heat to go out through the holes instead of heading in the direction of the oscillator. This did make an improvement. I'm now mostly seeing reports of -1Hz drift or even none at all. And I'm getting a lot more spots of my WSPR transmissions!
Monday, August 15, 2011
Should I or shouldn't I?
Thanks to the latest blog post from John AE5X I have the web page for a new QRP kit open in another browser tab and the pointer keeps hovering over the Buy Now button. The kit in question is the TJ2A, a two-band handheld SSB/CW transceiver for the 20m and 40m bands that has just been produced by YouKits of China.
Regular readers of my blog will know of my fondness for handheld radios. I'm finding this one very hard to resist even though I have an FT-817 and so no need for another handheld 20m/40m radio. At this point in my life I'm not even sure if building it is still within my capabilities. If I did try, it would be the most difficult kit I have attempted since my Elecraft K2, and I built that 12 years ago when my eyes were a lot sharper and I was not suffering the after effects of a brain operation. Should I or shouldn't I?
The TJ2A looks like an updated and improved version of the Mizuho HF handhelds that were produced during the late 1970s which still fetch a tidy sum whenever they change hands on eBay. Like the Mizuhos, the TJ2A is VXO controlled and covers a portion of each of the two bands, though you can install alternative crystals if you would prefer to have full coverage of one band in two ranges. You could also choose other bands by changing the VXO crystal and bandpass filters.
The building instructions are on the web and it looks as if the kit uses mostly through hole components but there are some SMD transistors. It isn't perfect. There is mention of warm-up drift in the first 5 minutes after switching on or changing bands. There is also a mod already to stop BFO leakthrough into the IF stages. And there doesn't appear to be any high SWR protection for the PA so using the rig with handheld antennas - or any type of antenna that presents a mismatch prior to tune-up - might be problematic.
But it looks really cute. And it's a kit. There are few things in ham radio more rewarding than hearing the first signals, then making the first contact, on a radio you built yourself. Should I or shouldn't I?
Regular readers of my blog will know of my fondness for handheld radios. I'm finding this one very hard to resist even though I have an FT-817 and so no need for another handheld 20m/40m radio. At this point in my life I'm not even sure if building it is still within my capabilities. If I did try, it would be the most difficult kit I have attempted since my Elecraft K2, and I built that 12 years ago when my eyes were a lot sharper and I was not suffering the after effects of a brain operation. Should I or shouldn't I?
The TJ2A looks like an updated and improved version of the Mizuho HF handhelds that were produced during the late 1970s which still fetch a tidy sum whenever they change hands on eBay. Like the Mizuhos, the TJ2A is VXO controlled and covers a portion of each of the two bands, though you can install alternative crystals if you would prefer to have full coverage of one band in two ranges. You could also choose other bands by changing the VXO crystal and bandpass filters.
The building instructions are on the web and it looks as if the kit uses mostly through hole components but there are some SMD transistors. It isn't perfect. There is mention of warm-up drift in the first 5 minutes after switching on or changing bands. There is also a mod already to stop BFO leakthrough into the IF stages. And there doesn't appear to be any high SWR protection for the PA so using the rig with handheld antennas - or any type of antenna that presents a mismatch prior to tune-up - might be problematic.
But it looks really cute. And it's a kit. There are few things in ham radio more rewarding than hearing the first signals, then making the first contact, on a radio you built yourself. Should I or shouldn't I?
Saturday, August 13, 2011
A WSPR Handy-Walkie
The VCXO-AXE WSPR transmitter has now been put into a plastic project box and lettered with Dymo tape. I think it looks rather smart even if I say so myself.
It did think about building it into a box that contained the batteries as well but that would have made it larger and prevent the batteries being used for something else. Plus I already had a box that fit the transmitter by itself. So what I now have is a pocket WSPR handy. Imagine going to the park or the beach or a hilltop and sending a signal that could be received half way round the world using a battery powered radio you can hold in your hand. How cool would that be?
Unfortunately the charger that charged my 10 AA cell NiMH QRP battery pack decided to fail and I'd exhausted the batteries during my initial tests so I couldn't try portable operation unless I first spent a day charging the cells up 4 at a time. So I decided to see how far my 30m WSPR signals would get using a selection of hand held QRP antennas with the rig running off the bench power supply in the shack. As most of the antennas are equipped with right-angle PL-259 connectors for attachment to the back of an FT-817 I attached them to the back of my SWR/power meter with a short patch lead connecting it to the VCXO-AXE. For an RF ground I used the nearby central heating radiator.
The Wonder Wand L-Whip produced several spots from as far afield as Italy during the morning.
The Miracle Ducker with 1.4m telescopic whip was somewhat less successful, though as I tested it at a different time of day it would perhaps be wrong to draw any conclusion from that. I used the MD with the radiator counterpoise. Although it would give a reasonable SWR with no counterpoise at all the current drawn by the VCXO-AXE TX increased from around 300mA to 400mA which made me think the PA might not be happy so I decided not to test it like that.
The most surprising result came from the ATX Walkabout antenna. For those unfamiliar with it, this is a small QRP antenna with a 1.4m telescopic whip and a base loading coil that is tapped for the 80m, 40m, 20m, 15m, 10m and 6m bands. To use the WARC bands with this antenna you have to use the tap for the next lower band and then obtain resonance by shortening the whip. On 30m the whip length is only about 40cm! The length of coil that is in use (not shorted out) is about 15cm.
So this antenna when used on the 30m band is effectively less than 2 feet long! Despite that it produced several spots at quite respectable SNR levels. The SWR using the radiator ground was a rather poor 3:1. I suspect that this, and overall efficiency, would have been improved if I had used a quarter wave counterpoise, but I didn't have 7.5m of wire handy and it would not have been practical to deploy it inside the shack in any case.
Obviously with a good antenna you will get stronger reports, be heard further afield and get more spots. But from the results of these tests it appears that even with a compromise hand held antenna (and a counterpoise for grounding) some interesting results could be possible using this little WSPR transmitter. Great fun!
It did think about building it into a box that contained the batteries as well but that would have made it larger and prevent the batteries being used for something else. Plus I already had a box that fit the transmitter by itself. So what I now have is a pocket WSPR handy. Imagine going to the park or the beach or a hilltop and sending a signal that could be received half way round the world using a battery powered radio you can hold in your hand. How cool would that be?
Unfortunately the charger that charged my 10 AA cell NiMH QRP battery pack decided to fail and I'd exhausted the batteries during my initial tests so I couldn't try portable operation unless I first spent a day charging the cells up 4 at a time. So I decided to see how far my 30m WSPR signals would get using a selection of hand held QRP antennas with the rig running off the bench power supply in the shack. As most of the antennas are equipped with right-angle PL-259 connectors for attachment to the back of an FT-817 I attached them to the back of my SWR/power meter with a short patch lead connecting it to the VCXO-AXE. For an RF ground I used the nearby central heating radiator.
The Wonder Wand L-Whip produced several spots from as far afield as Italy during the morning.
The Miracle Ducker with 1.4m telescopic whip was somewhat less successful, though as I tested it at a different time of day it would perhaps be wrong to draw any conclusion from that. I used the MD with the radiator counterpoise. Although it would give a reasonable SWR with no counterpoise at all the current drawn by the VCXO-AXE TX increased from around 300mA to 400mA which made me think the PA might not be happy so I decided not to test it like that.
The most surprising result came from the ATX Walkabout antenna. For those unfamiliar with it, this is a small QRP antenna with a 1.4m telescopic whip and a base loading coil that is tapped for the 80m, 40m, 20m, 15m, 10m and 6m bands. To use the WARC bands with this antenna you have to use the tap for the next lower band and then obtain resonance by shortening the whip. On 30m the whip length is only about 40cm! The length of coil that is in use (not shorted out) is about 15cm.
So this antenna when used on the 30m band is effectively less than 2 feet long! Despite that it produced several spots at quite respectable SNR levels. The SWR using the radiator ground was a rather poor 3:1. I suspect that this, and overall efficiency, would have been improved if I had used a quarter wave counterpoise, but I didn't have 7.5m of wire handy and it would not have been practical to deploy it inside the shack in any case.
Obviously with a good antenna you will get stronger reports, be heard further afield and get more spots. But from the results of these tests it appears that even with a compromise hand held antenna (and a counterpoise for grounding) some interesting results could be possible using this little WSPR transmitter. Great fun!
Thursday, August 11, 2011
Whispering with a VCXO-AXE
My VCXO-AXE WSPR transmitter kit from W5OLF came this morning. It was two weeks in the post, doubtless due to Customs which had opened the package. I wasted no time in building it, though it did take me somewhat longer to complete than it took AE5X.
The kit itself has been impressively put together. The PCB is extremely high quality and the instructions are almost of Elecraft standard. If the horrible Spectrum Communications Off-Air Frequency Standard kit had been produced to this level of quality it might not have turned out to be a failure for me. If American kit makers can produce nice silk screened and solder masked boards, why do ours make us struggle with boards that look like they were made by hand on somebody's kitchen table?
The VCXO-AXE kit uses almost all through hole components and there is plenty of space around the solder lands. I doubt that anyone would have any trouble building this. The one part that induced a feeling of terror when I saw it was the VCXO itself.
As described, it is a "larger surface mount component." But what I didn't expect was that it didn't have any pins or legs that stick out to solder to. Instead, you have to solder it so the solder goes under or up the side of the chip. You need a very fine tipped soldering iron for this. I couldn't really see if I had successfully soldered the chip or not, so I took a couple of pictures.
The result is not very pretty, but it must have been OK because the transmitter eventually worked!
When ordering, I specified my call, locator and the supply voltage I would be using (12V, as I planned to power the transmitter off a pack of 10 NiMH batteries.) The PICAXE controller chip came programmed with this information and a power level of 33dBm - 2 watts.
On a freshly charged battery pack I was actually getting nearer 3 watts output once the PA tuning capacitor had been peaked up, but after the first few transmissions the power did drop off a bit to become nearer the advertised 2 watts.
I hooked the VCXO-AXE up to my attic MFJ magnetic loop, watched the radio-controlled clock in the shack until it rolled over to an even minute, pressed the transmit button and a couple of minutes later had my first WSPR spots.
Soon after that I had several more. No great DX, but perhaps that is just down to conditions at the moment.
The instructions warn that second harmonic suppression of this transmitter is not great and an external low pass filter is advised. However, the magnetic loop (either the MFJ or my portable Wonder Loop) has a very high Q which I am sure does a good job of attenuating out of band harmonics on its own.
My next move will be to build the little transmitter into a plastic box and use it as a hand held portable WSPR rig. It would be fun to try making a 30m base loaded whip - which should also be fairly high Q - and see how well that works. So expect some WSPRing from various locations around Cockermouth some time soon!
This was a fun project and a good morale booster to prove to myself that I can still build stuff - and with an SMT part in it, too! Thanks to Jay W5OLF for making the kit available. A 20m version would be nice, as well!
If you want to buy one of these kits for yourself you have to look on eBay, though as of right now there doesn't seem to be any for sale.
The kit itself has been impressively put together. The PCB is extremely high quality and the instructions are almost of Elecraft standard. If the horrible Spectrum Communications Off-Air Frequency Standard kit had been produced to this level of quality it might not have turned out to be a failure for me. If American kit makers can produce nice silk screened and solder masked boards, why do ours make us struggle with boards that look like they were made by hand on somebody's kitchen table?
The VCXO-AXE kit uses almost all through hole components and there is plenty of space around the solder lands. I doubt that anyone would have any trouble building this. The one part that induced a feeling of terror when I saw it was the VCXO itself.
As described, it is a "larger surface mount component." But what I didn't expect was that it didn't have any pins or legs that stick out to solder to. Instead, you have to solder it so the solder goes under or up the side of the chip. You need a very fine tipped soldering iron for this. I couldn't really see if I had successfully soldered the chip or not, so I took a couple of pictures.
The result is not very pretty, but it must have been OK because the transmitter eventually worked!
When ordering, I specified my call, locator and the supply voltage I would be using (12V, as I planned to power the transmitter off a pack of 10 NiMH batteries.) The PICAXE controller chip came programmed with this information and a power level of 33dBm - 2 watts.
On a freshly charged battery pack I was actually getting nearer 3 watts output once the PA tuning capacitor had been peaked up, but after the first few transmissions the power did drop off a bit to become nearer the advertised 2 watts.
I hooked the VCXO-AXE up to my attic MFJ magnetic loop, watched the radio-controlled clock in the shack until it rolled over to an even minute, pressed the transmit button and a couple of minutes later had my first WSPR spots.
Soon after that I had several more. No great DX, but perhaps that is just down to conditions at the moment.
The instructions warn that second harmonic suppression of this transmitter is not great and an external low pass filter is advised. However, the magnetic loop (either the MFJ or my portable Wonder Loop) has a very high Q which I am sure does a good job of attenuating out of band harmonics on its own.
My next move will be to build the little transmitter into a plastic box and use it as a hand held portable WSPR rig. It would be fun to try making a 30m base loaded whip - which should also be fairly high Q - and see how well that works. So expect some WSPRing from various locations around Cockermouth some time soon!
This was a fun project and a good morale booster to prove to myself that I can still build stuff - and with an SMT part in it, too! Thanks to Jay W5OLF for making the kit available. A 20m version would be nice, as well!
If you want to buy one of these kits for yourself you have to look on eBay, though as of right now there doesn't seem to be any for sale.
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