Thursday, December 31, 2009

Happy New Year 2010

I just took a look at my Blogger control panel and I have made 300 posts this year. Not a bad start!

I would like to wish all my readers a Happy New Year 2010. I hope it brings happiness and health, greater prosperity and job security, and more time for the things you enjoy doing and the people you love.

I also hope it brings many more sunspots and lots of tropo and Sporadic-E on VHF!

Tuesday, December 29, 2009

Change of resistance

I hate getting old! Last night my lower back was in agony from the couple of hours I spent hunched over the desk working on the SoftRock 6.2 Lite kit. So I didn't plan on doing any constructional work today. However, Maurice G4DVM read of my problem with the kit and asked me to send him some voltage measurements. It also occurred to me that I had tested the circuit with the power supply set to 9V instead of 12V. So I connected the kit to a 12V power supply, switched on the FT-817 (which was still set to 8.191MHz from yesterday) and this time a carrier signal was heard!

I started taking voltage measurements anyway and observed that the voltage on pin 2 of U2 was low: 0.79V compared to the 2.47V obtained by the author of the instructions. Pin 3 was 1.23V compared to 3.21V expected. More importantly I observed that the oscillator signal stopped as soon as the test probe touched the pad. Around this time I observed that oscillation also stopped if I touched the case of the crystal and it didn't always start up again afterwards. So I probably wasn't mistaken that I didn't detect the local oscillator signal yesterday.

According to the instructions, R6 (which has something to do with the bias of Q2) is not used in most versions of the SoftRock except for 40m. It is supposed to be used in the version for the K3 IF, and the value supplied is 22K. I thought it would be an easy test to remove it - just snip the exposed lead (since it is mounted on end.) If that didn't help I could always solder the ends back together again.

With R6 open circuit there was no local oscillator at all. I then decided to try a lower value. The instructions say a value from 12K to 22K may be used "as appropriate". I found a 15K resistor and tacked it across the pads on the underside of the board. I had a local oscillator again and this time it didn't stop when I touched the case of the crystal!

I absolutely hate replacing components in circuit boards with plated through holes. Removing the snipped in half 22K resistor from the circuit board was easy. But clearing the holes to allow the 15K resistor to be inserted in its place was a job I dreaded. Ironically it would have been easier if the SoftRock kit was all SMT - apart from the fact that I wouldn't have had a 15K SMT resistor to try.

I have a spring-loaded desoldering gun, but I didn't think I could use it as it was designed for larger boards with more space between the components and the holes. I have desoldering braid too, but most times I have used it I ended up lifting pads and traces on the board. I made a real mess of modifying the KSB2 board in my early model Elecraft K2. The board works, but it is a good job no-one can see it.

In the end I did the job using a couple of stainless steel needles from Olga's sewing kit. I heated up a hole and quickly pushed a needle through, then cleaned up the solder that was pushed through. It took a couple of attempts to clean the holes sufficiently for the replacement resistor's leads to pass through.

By the time I had finished the modification and checked that I still had an 8.191MHz signal my back was painful again. So much as I would have liked to finish the SoftRock and see if it works I shall have to pack it and my tools away and leave it for a few days. I hate getting old!

Monday, December 28, 2009

A good match

Out of all the discussion about whether the Elecraft K3 receiver is or isn't noisy, one thing that eventually became clear was that a lot depends on the speakers and headphones you are using. I found that my K3 sounded much better when I tried a pair of Sennheiser HD-485 headphones that I'd bought for music listening, which had an impedance of 32 ohms compared with the 8 ohms of the old pair I'd been using. The passive communications speakers I was using sounded shrill and lacking in bass compared to the computer speakers I'd used before. However, my attempts to find powered computer speakers that were RFI proof by trial and error had turned out to be rather costly.

This afternoon I walked down to Aldi with Olga to get some shopping and, after some hesitation, decided to take a chance on a pair of Medion Multimedia PC Speakers that were being sold there for £7.99. Aldi offers a 30-day no-quibble refund if you aren't happy with something, so if the usual rasping noises occurred when I spoke into the mic I could easily take them back.

The Medion speakers sound very good when plugged in to the rear speaker socket of the K3. They have a very effective tone control that completely eliminates any tiring noise or hiss in the fully clockwise position, and they can provide plenty of bass for "armchair listening." What's more, I found them completely free of any RF breakthrough when running 100 watts of SSB to my attic antennas which are directly above the shack - a tougher test than they'll experience in most shacks, I'll bet.

I think the modern styling of these speakers suits the Elecraft K3, and the black and silver finish matches my Heil desk mic and my Bencher straight key very nicely.

Another good point about these speakers is that they run off 14V DC from an external adapter with a standard barrel type plug. This means that you can easily power them from your shack power supply and avoid the need for another power-consuming wall-wart. A 14V 800mA unregulated analogue wall-wart power supply is provided, and could probably find a use in another project - you'd pay £4 or more for that alone at Maplin.

Whether you need some external speakers for your radio or some RFI-proof speakers for your computer (or a neighbour's) these Medion Multimedia PC Speakers look like a good investment.

On the rocks

A disappointing day in the G4ILO shack. I did some more work on the SoftRock 6.2 Lite kit which I was hoping to make into a panadapter for my K3. But the project has hit the rocks as the local oscillator doesn't work and I don't know what to do about it.

I started off by adding the components for the regulated power supply. That checked out fine - not much to go wrong there, really.

Next I built the crystal oscillator part of the circuit. That also worked fine - I could hear a strong signal just below 32.768MHz on my FT-817 receiver.

The stage after that was the divider circuit, which is supposed to divide the oscillator frequency by 4 to give the 8.192MHz local oscillator required by the K3 version of the SoftRock. I didn't need to add any components for that, as I'd already soldered in all the SMT components and this stage just involved adding the divider ICs. So I tuned down to 8.192MHz and heard nothing.

The current consumption of the SoftRock was correct for this stage, but some of the voltages on pins of U2 were not correct. There was zero volts on pin 2 where there should have been a reading. I checked the board carefully but I could not see any solder bridges or anything else I have done wrong. I don't have an oscilloscope so I can't see what is happening.

I don't know what is wrong, and I don't know what to do. Perhaps it was a mistake to solder all the SMT parts first, but I really would not have liked to do it after the through-hole components were added, making access difficult. Perhaps my anti-static precautions weren't good enough. I did use an anti-static mat and wrist band, but I'm getting pretty absent minded these days and there were times I forgot to connect the ground strap to the wrist band before handling the board.

I don't have any replacement divider ICs to try, and to be honest I find the board too small to work on. I doubt that I could remove a chip without lifting the PCB pads at the same time. I don't know why the SoftRock couldn't have been designed using all through-hole parts with socketed ICs, on a larger board. It doesn't appear to use any components that aren't available in leaded versions, and it would have made the project easier to build and easier to troubleshoot for most people.

The SoftRock has gone into the box of projects that didn't work, along with my short-lived enthusiasm for SMT construction.

Sunday, December 27, 2009

Ghost town

The floods that hit Cockermouth just over a month ago may just be a long-forgotten news item for most people but they are still very much in the minds of people here. Through the energy and initiative of private enterprise, the resourcefulness of the local community - and no help at all from the local council - several local Cockermouth businesses have re-opened in temporary premises in a higher part of the town near the main supermarkets. Life goes on as best it can. But our quaint Georgian main street is like a ghost town. Here are some pictures from Cockermouth as it is today.

The footbridge over the river is down

Main Street is still closed to traffic

Most of the Main Street shops are still boarded up awaiting repair

Skips still line the street

Wordsworth House, the birthplace of England's greatest poet and the twon's main tourist attraction, was damaged by the floods

Many other bridges and structures are seriously damaged

Trust private enterprise to take the initiative - this travel agency was open for business in new premises the day after the flood

Message on a "tree of hope" in Market Place

Meanwhile the local authority has been reported in the local press as:
  • Objecting to the construction of an emergency Tesco supermarket on the north side of the river in Workington to help local people who have a 25 mile detour to reach existing supermarkets on the south side, because planning procedures had not been followed.
  • Delaying the construction of new road bridges by insisting that bureaucratic procurement procedures be followed, despite the fact that construction companies could build a new bridge "in weeks."
  • Penny-pinching over the cost of extra school buses needed to take schoolchildren isolated on the north of the river to their schools in the south.
  • Re-painting the yellow lines to show parking restrictions on the still closed to traffic Cockermouth streets.
The county council recently appointed a new chief executive, a former social worker, on a salary of £170,000 a year. Perhaps what is needed is a council run by people with business experience to help get the county back on its feet.

Saturday, December 26, 2009

Whispering over Christmas

I thought I would try to keep out of the shack over Christmas. Instead I decided to participate in the two day 40m QRP activity period organized by WSPRnet.org. Late on Christmas Eve I set up my computer and K3 to transmit WSPR beacons on 40m with 500mw output using my MFJ magnetic loop. Apart from popping in from time to time to see what was happening I left it to it until late this evening when WSPR was brought to a halt by a poorly designed website.

The 200Hz-wide WSPR band was very busy, as the screen dump shows. My half watt signal to an attic antenna was spotted by 186 different stations. Best DX was: VK6POP (14706km), W8LIW (5779km) and W8ETO (5002km).

My station decoded signals from 176 different stations, not all of whom were running as little as half a watt. Best DX was VK5VCO (2w - 16357km), VK6BN (10w, 14704km) and W8DA (10w, 5806km). The furthest station running half a watt that I received was IK4GBU, at just over 1500km. I guess this shows the impact of my noisy location on my ability to decode weak signals, since others were copying my half watt signal from much further away.

I spotted, and was spotted by, two of my fellow ham radio bloggers: PC4T and PE4BAS.

The best DX occurred on Christmas Eve and Boxing Day evening. On Christmas Day evening at the same time only European stations running more than half a watt were showing up. The solar flux was unchanged but the A index jumped to 5 at that time, and the K index also rose. I wonder if this was the cause?

Wednesday, December 23, 2009

Merry Christmas 2009

Wishing all my readers a Merry Christmas 2009!

Breaking my SMT duck

It was nagging at me like a persistent toothache. The SoftRock kit was sitting in an envelope with all the parts sorted and the instructions printed, waiting for me to start building. But the anxiety about soldering the SMT parts made me put off starting. Finally, this afternoon, I decided to bite the bullet and make a start.

The first snag was my soldering iron. The regular sized bit had seized on to the shaft of my Antex TCS. I could not get it off, so I could not replace it with the small one I had bought for just this task. In the end I decided to use my 40 year old Antex Model C. Years ago I bought a fine tipped bit for it which I had always found to be too feeble for any projects I had built. Miraculously I had not managed to lose it during all that time, so at long last it was to be of some use!

I made the decision to mount all the SMT parts first, instead of building the board stage by stage. I thought that would make the task easier by keeping the board flat and not restricting access to the SMT pads in any way. I decided to start with what I thought would be the easiest parts: the 0.1uF SMT capacitors. There are 10 of those in the SoftRock 2, and 11 were supplied, so I had one spare!

Things did not start well. For the first one I made the mistake of deciding to tin (apply solder to) the two pads before soldering. This made the pads uneven which made it even more difficult to hold the capacitor in position for soldering than it normally is. At the first attempt the capacitor was standing a bit proud of the board at the other end. I applied some pressure with tweezers to try to level it out. Only after I had soldered both ends and then inspected my work did I see that I had cracked the component. So I had to remove it and start again - my one spare lost before I had even started!

I nearly gave up at this point. I had spent about 15 minutes trying various ways to hold the component still so I could fix it with a dab of solder at one end. "OK", I thought, "SMT is not for me. This is no fun at all." I was close to packing the SoftRock all away and giving the kit to someone else. But then I thought "what the hell." There was nothing to lose by trying. The kit hadn't even cost me anything, thanks to the generosity of Craig VK3HE. So I tried again.

Eventually I hit on a technique that worked. I used a bronze bladed trimmer tool with BluTack on the end to pick up an SMT part and hold it in position. The BluTack was necessary because otherwise the slight tremor in my hands would jiggle the capacitor out of position. Then I would fix one end in place with a blob of solder from the fine tipped bit. Next I would solder the other end of the part. Then finally I would go back to the first end and try to make a better job of it.

I should point out that this was only possible with the aid of a headset with magnifying lenses that I bought on eBay several years ago. It took nearly an hour to solder in all 10 capacitors, and my back was protesting a bit at all the bending close to the desk to get the board in focus with the high magnification lenses I was using. Only one capacitor pinged off into my lap and fortunately I immediately saw it. If I had lost one in the carpet that would have been that.

I was going to quit while I was ahead but I was fired up and wondering how I would manage with the SMT ICs in the kit. There are four of them. The instructions say to use electrostatic precautions so before I could carry on I had to unroll the electrostatic mat and ground it using the negative terminal of my shack power supply.

Amazingly, I found the SMT ICs easier to install than the small capacitors. Contrary to all the advice found on the web I did not use flux and desoldering braid. I soldered each leg of each IC individually, just as I would do with through-hole components. The fine-tipped soldering iron bit made this possible, as did use of some 0.2mm diameter solder that I had purchased on eBay. Thanks to the fantastic macro facility of my new £25 digital camera you can have a good look at the result.


I used a couple of small balls of BluTack to anchor the PCB to the work surface, then picked up the IC with tweezers and dropped it on to the board. Then I nudged it into the correct position using one end of the bronze tipped trimming tool. I held the IC in position using the other blade of the trimming tool which had some BluTack wrapped round it, and quickly tacked one corner leg to the board with solder.

Next I rotated the board so I was looking at the other side of the IC, checked that all the pins still lined up with the pads, and tacked the opposite corner leg into position. I then soldered all of the pins individually by applying the fine tipped bit and fine 0.2mm solder.

I mounted all 4 ICs in less than an hour and did not create a single solder bridge, which is better than I usually manage soldering regular sized through-hole parts! I am over the moon to have broken my duck and overcome my fears of working with SMT components, though my back is telling me that two hours of this in one session is more than enough!

Monday, December 21, 2009

Now I'm TalkTalking

Last Friday I finally changed ISP from OneTel to TalkTalk. It has taken a bit longer than I thought when I originally wrote about it. I originally thought I would switch from OneTel to British Telecom. However, this was complicated because my line is rented from OneTel. BT are very good at sending junk mail and phoning at inconvenient times (even though we are ex-directory) to try to persuade me to switch back to them. They have been doing this ever since I first switched to OneTel. They claimed they would handle the business of getting some magic number that was needed to switch the line back, but when it came to the crunch they were completely lame and nothing happened so I gave up the idea for a while.

A couple of weeks ago I was getting long pauses "looking up google.com" and other sites and started getting discontented again. I looked at the results of broadband speed checks in my area and found that many people were getting faster speeds than I was. Some of those with the highest speeds were using TalkTalk. OneTel was taken over by TalkTalk a couple of years back but I had never been offered an upgraded package and I discovered I was paying more for a 2Mbit/s broadband service than TalkTalk was charging for a 24Mbit/s service. So I phoned them up and asked them to switch me to the TalkTalk Pro package.

I was very impressed with the way the changeover was handled by TalkTalk. I was sent plenty of information updating me on the progress of my order and also received several days in advance a free D-Link wireless router preconfigured with my account details. However I wanted to use my existing Draytek Vigor 2800VG router which has built-in VoIP support (which I use for a second phone line) and the ability to use a 3G mobile broadband USB modem as a backup for the ADSL. So I connected up the D-Link and copied all the settings from it (fortunately the password was shown in clear) ready to enter into the Draytek.

Changeover day came on Friday. The old broadband connection was down, so I typed in the new settings and was swiftly connected to TalkTalk. After a bit of trial and error with the modulation type I found the fastest setting and everything seemed to be working. Until I tried to access Gmail. After log-in to my Gmail account the browser froze for a minute or two then displayed a blank page. This happened repeatedly, using any PC. Disconnecting TalkTalk so that the router fell back to the 3G connection allowed Gmail to be accessed with no problems, so clearly this was a problem with TalkTalk.

Some serious Googling ensued. There seemed to be an issue with TalkTalk, Gmail and the MaxMTU setting. MTU means "maximum transmission unit" and it determines the maximum size of a packet that can be sent over the internet. If it is set too large, a packet has to be split into two or "fragmented". This is bad for performance, but it appears that often it doesn't arrive at all. The normal MaxMTU setting is 1500, but TalkTalk's router was set for 1432. I tried setting the Windows MaxMTU to that value using the DrTCP tool but it didn't help. I even tried some smaller values but still got nowhere. Clearly I was going to have to get support from TalkTalk, but I guessed they would put the blame on my router unless the one they supplied also had the problem, so I thought I had better try it.

When I connected TalkTalk's D-Link DSL-2740R wireless modem router there was no problem accessing Gmail. This was a bit frustrating. I didn't want to give up the Draytek and do without my VoIP second phone line or my 3G backup but it looked as if I was going to have to use the D-Link. I then tried testing other things that we use on the Internet and found that both of the laptops which run a Linux distribution called Xandros could not connect to the wireless at all. I also found that the Reciva-based wi-fi internet radios reported trouble connecting to the Reciva website, complaining that a port was blocked even though I hadn't touched the firewall settings.

I decided that I would have to use the Draytek, which is what I wanted to do anyway, so I started searching their support forum. There I found someone else had experienced the problem with accessing Gmail through TalkTalk and found the solution was to reduce MTU on the router to 1200. For the benefit of anyone else that has this problem, you do this by logging in to the router using Telnet and entering the command wan ppp_mss 1200. Who would have guessed it? Now I can apparently access all websites, everything else is working and I'm a happy bunny.

Or at least I was until this afternoon when I went back to the broadband speed test site and ran some new speed tests. TalkTalk's sales people reckoned that from my location I should be able to get about 13MBit/sec. Using my Draytek Vigor 2800VG the maximum download speed I can get is only 8MBit/sec. Using TalkTalk's supplied D-Link router I can get nearly 11.5Mbit/s.

I suppose it doesn't really matter. The wireless laptops can't transfer data that fast anyway. Neither can the one hard wired PC - the old Acer in the office / radio shack - because its network card is normally set to 10Mbit/s due to the fact that when set to 100Mbit/s it radiates a strong carrier right on the 2m FM calling channel.

VHFDX.INFO

The very useful VHF DX Sherlock site run by Gabriel, EA6VQ now has a new location, VHFDX.INFO. Gabriel has moved the site to a new server in order to overcome the problems experienced with his original provider. The site is still up and running under its old domain name, VHFDX.net, on the old server, until it is certain that everything works on the new server just as it did before. After that the old domain will also point to the new server. Gabriel requests as many people as possible to try the new location and report to him anything that appears to be wrong.

This site is a very valuable resource for VHF enthusiasts that enabled me personally to catch many Sporadic-E openings I would probably otherwise have missed, and I wish it many years of trouble-free operation on its new server.

Sunday, December 20, 2009

Snow falls, continent isolated

A bit of snow in the south east has apparently caused electrical failures on the railway line through the Channel Tunnel. Services have been suspended until further notice. Many airports are also closed and flights grounded due to snow on the runways. Bad news for anyone hoping to leave the UK for Christmas.

Every winter we have snow and ice. It's cold, it's wet and it freezes. Any child knows that. Yet in Britain we still don't seem to have learned how to design transport systems that can cope with it.

A lot of noise about noise

A very long discussion has been raging on the Elecraft reflector in the last few days over whether the K3 receiver is noisy. This discussion has remained surprisingly well-mannered although there have been one or two instances of someone complaining about someone else making criticisms of the K3 that they can't personally hear or see.

Paul, WW4PT has suggested that the problem is with people who won't use the RF Gain control. While I dare say that may be the answer for some of the people who complained that their K3s were noisy, I found it hard to say if that was the only issue being experienced. Some complained of the K3 being tiring or fatiguing to listen to for a long period. Others suggested it may be due to high frequency artifacts produced by the DSP. (Incidentally, why do people use the word "artifacts" in this way? I thought artifacts were objects made by ancient cultures.)

One benefit of the discussion is that it got a lot of people to experiment to try to put a finger on the problem. I always found the K3 audio to be a bit lacking in bass compared to other receivers, and actually preferred listening to SSB on my FT-817ND. After experimentation I found that the problem was partly due to the external speakers and headphones I have been using.

Early K3s used too small values of coupling capacitors in the audio output stages resulting in the loss of a lot of bass. Modifications have been published for the line output and speaker output, and I have carried out those mods on my K3, but the headphone output requires a modification to the DSP board that is deemed too difficult for DIY. The only solution is to return the DSP board for exchange, which Elecraft offers for $69, but by the time you add in international shipping, taxes and tax collection fees for those of us in the UK that will come to more like £69, which is quite a lot to spend to remedy what was arguably a fault in the original K3 design.

Fortunately there is a cheaper solution: use high impedance headphones. And it just so happened that I had a suitable pair of Sennheiser headphones already, which I bought to use with a Sony Walkman CD player. Even with these headphones I still prefer a "warmer" sounding audio, but the K3's receive equalization settings provide all the audio tailoring I need.

During the course of my experiments I used Spectran to analyze the audio output of the K3. What I found was interesting. The K3 has a text-book filter response with steep sides and a flat top, and virtually no noise (more than 100dB down) outside the filter passband. (See the screen grab above.) By contrast, the FT-817 frequency response falls away more gradually, containing considerable energy even at frequencies of 10KHz or more. Don W3FPR did some similar tests with his FT-817, his K2 and some Yaesu radios and got similar results. The absence of unwanted high frequency energy in the K3 output makes the receiver sound clearer, but it also allows you to hear noise more clearly, where other receivers produce a soothing mush. This might also be a reason why some people claim the K3 sounds "noisy".

After making some equalization changes, swapping to the high impedance headphones and getting rid of the external speakers my K3 sounds great. I just need to find some small external speakers that have a good bass response when used with the K3.

Friday, December 18, 2009

Smoothed sunspot number data updated

I have just updated the file of smoothed sunspot numbers (SSN) for VOAProp from this NOAA data file: ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SUNSPOT_NUMBERS/sunspot.predict.

I see that the maximum is being predicted to occur in March 2013 with a value of just 83.3 - about what we had half way through the decline of the previous cycle at the start of 2003, if you can remember what conditions then were like.

The smoothed figures put the minimum of the last cycle as last December, a year ago, with a value of 1.7. The predictions now run up to 2020 and the minimum of the next cycle is expected to be in January of that year with an SSN of 5.6.

This is the first time I have updated the SSN data file for about six months. I think that NOAA updates the data every month, but VOAProp requires the data in a different format. Updating it is something of a chore and I can't be bothered to do it very often as it doesn't change all that much from month to month.

I rarely use VOAProp myself and have come to the conclusion that propagation prediction software is almost worthless for amateur use, except to demonstrate to newcomers to HF radio the broad principles of how the time of day, the seasons and solar activity affect propagation to different parts of the globe.

The VOACAP engine used by VOAProp was developed by a short wave broadcaster and designed for broadcast use, and broadcasters are concerned about where and when propagation is reliable and strong. It is the fleeting moments of unpredictable propagation that are of most interest to we amateurs. I think the results of real-time prediction monitoring carried out by users of WSPR and Propagation Reporter are of far more use in showing what propagation is really like.

Thursday, December 17, 2009

Gold plated

If you are in need of cheering up this morning, take a look at the product listing for this Wattgate 381 Audio Grade Duplex Socket, and scroll down to the reviews.

For the sake of your computer, do not have a mouth full of coffee when you start reading!

Who said geeks don't have a sense of humour?

Tuesday, December 15, 2009

Car Parks On The Air

As the instigator of the Wainwrights On The Air scheme I hope this does not come across as a case of the pot calling the kettle black, but I think the mania for "Things On The Air" is getting a bit out of hand.

Courtesy of Dan KB6NU's Blog I have just learned about Railroad Depots on the Air, a group whose aim is to set up radio stations at railroad depots and so that people can collect points by making contacts with them. Where will it all end? I suppose the road transport enthusiasts will set up a competing activity Bus Stations On The Air, if they haven't already.

I wonder if the people who dreamed up Islands On The Air knew what they were starting? Islands tend to be a long way away and expensive to get to, so Richard G3CWI came up with Summits On The Air (SOTA) which offered activators a large number of entities to activate without having to leave the country. Wainwrights On The Air is really just a local, junior SOTA. But both of those schemes have the disadvantage for the average ham unfit from too many hours slouched in front of the radio that you need to hike to the top of the mountain with your gear before you can activate it. So some awards for working easier to reach entities might be welcome.

Pubs On The Air would be extremely popular, especially with me. Certainly the lounge bar of the Bitter End in Cockermouth would make a more pleasant operating location than the top of Helvellyn in a hailstorm. But activators would be wise to get all the CW contacts over and done with at the start of the activation, with PSK31 reserved for just before closing time.

You could also have some programmes of a more topical nature. In Recession Victims On The Air you could earn points from contacting stations operating from closed-down Woolworths and MFI stores.

Car Parks On The Air would be the one for real couch-potato activators. All you would need to do is drive there, park up, turn on the mobile rig and start making contacts. You could even ask people wanting a paper QSL to make a donation to cover the cost of your Pay and Display ticket.

I'm sure you can think of plenty of others...

Free software

There has been a lot of excitement recently about the release of a Technology Preview of SDR-Radio.com, the new software defined radio console named, for some curious reason, after its website domain, which is being developed by Simon Brown HB9DRV of Ham Radio Deluxe (HRD) fame.

What seems to have passed unnoticed so far is that, unlike HRD, SDR-Radio.com is not going to be freeware. A note in a corner of one page of the site says that licensing details are to be announced for the more advanced SDR platforms but soundcard (SoftRock) users will get a 30-day free trial after which the program will still run but with some serious nag-ware!

A few years ago Simon used to really get up my nose with his announcements of new versions of FT-817 Commander and HRD on various mailing lists. The announcements would always be accompanied by the information that the software was not merely free, but ***FREE*** software written by radio amateurs for radio amateurs. There used to be a page on the HRD website that was virtually a political statement, stating that ham radio software should be free, and that hams who charged for their programs were parasites (or something on those lines) taking money from the pockets of fellow hobbyists.

I remember this very well because at the time I was struggling to set up a software business to supplement my dwindling income from freelance computer journalism. My ham radio programs were more popular than the utilities I was trying to sell, and I was very tempted to try to develop a ham radio program commercially. Except that according to Simon and others who supported his position that would have made me an evil profiteer who should be cast out of the hobby altogether.

Today when you visit the Ham Radio Deluxe website the first thing you see is a request to "support Ham Radio Deluxe" by making a donation. And SDR-Radio.com is going to be commercial from the outset. I'm not criticizing Simon for this in the slightest. Developing software, whether for a hobby or anything else, takes time and costs money and there is no reason why people shouldn't try to earn something from it. But I really couldn't pass by this about turn over the principle of whether ham radio software should be free without commenting on it!

Not an Emergency Service

My January 2010 QST arrived today. I turned to the editorial captioned "Not an Emergency Radio Service?" which quotes an FCC Public Notice stating "the amateur service is not an emergency radio service" and says "We might take umbrage at that." It then proceeds via a convoluted argument to conclude that the FCC considers amateur radio to be not an emergency radio service only because it is so much more.

Were I an American radio amateur I would not have taken umbrage at all. I think the FCC's words mean exactly what they say. Of course it is right and natural that radio amateurs who find themselves in or near an emergency situation where the use of their equipment can be of help should volunteer their services if they wish. But passing emergency communications is not what our frequencies are for, and amateur radio organizations should not be organizing and training operators to handle emergency messages within the amateur bands.

If radio amateurs want to use their radio skills to help with local emergencies there are many organizations they can join that I'm sure would welcome them with open arms. For just one example from here, the Mountain Rescue Service is an entirely voluntary body that uses radio in the course of its activity. But it uses its own equipment on its own frequencies.

Here in Cockermouth during the recent floods the Mountain Rescue, the Red Cross, the RAF, the Army, the police and the ambulance service and doubtless others were all involved. There was nothing but praise for the way the rescue services did their job. To the best of my knowledge amateur radio operators were not involved and all communications were handled on the rescue services frequencies. That, in my opinion, is exactly as it should be.

Monday, December 14, 2009

DX on 20m

It doesn't take much to liven up the HF bands. An SSN of 14 and a flux of 76 and I heard (and worked) several US stations and an Indonesian.

I was monitoring on 14.070 with KComm's PSK Browser open and saw that I was decoding YC1FWO from Depok in Indonesia. I double-clicked on his call to put myself on his frequency. During the previous contact he mentioned that he was running 50W so I increased my power to match, and when he finished the QSO I called him. He came right back and we had a solid contact, my first on PSK31 with Indonesia. (I worked the country once before, a year ago, on CW during the CQ WW contest.)

Listening again after that contact was over I saw someone's station details scroll by and noted that they were using an Elecraft K3 like I was. It took a little while to get Paul NF8J from Alto, Michigan in the log. The first time I called, he replied to a German station whom I couldn't hear. I waited on frequency but an Italian, who possibly couldn't hear Paul, kept calling CQ on top of him. When he signed with the German I waited a little while for the other station to send his final goodbyes and then called. Another Italian station then called me! I called again and this time Paul came back to me and we had a nice contact that didn't just consist of macro exchanges.

A bit later on I heard Carl K4RH from Murfreesboro, Tennessee calling CQ DX. Again, the first time I called him he returned to someone else. While he was half way through sending their signal report a Spanish station kept calling him! When he finished the contact I called again. Carl heard the signal from my attic dipole and a short but solid contact was completed. I think Tennessee is a fairly rare state so I was pleased to work him.

Sunday, December 13, 2009

Geminids

I switched on the computer just after 10pm and saw Roger G3XBM's post about the Geminid meteor shower, so I set the K3 to 50.230MHz JT6m, put on a warm coat and went outside to take a look. The radio didn't receive anything but in the space of about 15 minutes I saw three bright, slow moving meteors.

I have had a moderate interest in astronomy all my life. In fact, there is a small Celestron telescope occupying a valuable corner of the already cramped G4ILO shack which I have been intending for months to put back in its box and put up in the loft because it hasn't been used for at least three years. The main reason, apart from the Cumbrian weather, is that we are surrounded on all sides by street lamps (not to mention the neighbours' security lamps) which makes any real enjoyment of the night sky impossible.

Directly at the back of the house are two orange sodium lamps, but I noticed for the first time this evening that another lamp down the road had been replaced by a brighter reddish-white kind of lamp that was even worse and killed any chance of seeing stars in the northerly direction.

I had an unhappy thought. Astronomy enthusiasts, whom I believe to be more numerous than radio amateurs, have failed to convince councils to install downward-focussed non-light polluting types of street lamps that would not interfere with viewing the night sky, so what hope have we of persuading the powers that be to outlaw devices that interfere with radio reception?

Saturday, December 12, 2009

People in glass houses

It probably goes without saying that someone who has a blog has opinions they have a burning desire to tell the world about. And if you have opinions, you have to be prepared for people to disagree with you. As a blog owner, you have the right to allow or delete comments. However I have always believed that you should allow the dissenting voices to have their say as well as those that support you. The only comments I have ever deleted from this blog have been ones that appeared to be spam and did not relate to the subject of the posting.

I recently found a rather nicely produced blog called Radio & Other Interests by John Harper AE5X. In a recent post he describes trying PSK31 and feeling insulted that people were sending macros instead of typing a reply especially for him. One person commented to this post that he found the canned replies no more or less insulting than the rubber stamp reports in a contest. I added a comment in the same vein, saying that it wasn't an insult just progress, using the computer to save typing the same information over and over. That comment never appeared on the blog, but computers screw up and I didn't lose sleep over it.

Today I added a comment to John's post about 10 metres being dead for the ARRL contest, saying that I had noted one WSPR spot on the band so far and hoping that people over there had managed to work something. I also wondered why the ARRL scheduled a 10m contest now rather than during the Sporadic-E season. That comment was still "pending moderation" earlier this afternoon, but this evening it too had disappeared without trace. I think deleting comments from people who have taken the trouble to reply after reading your blog is pretty insulting.

In his post about Elecraft K3 demos John uses a clever word (which he doesn't even spell correctly) to denigrate my contributions to the Elecraft email reflector. AE5X may feel he is being insulted when people reply on PSK31 using a macro but that's a bit rich coming from somebody who uses his blog to insult a person he has never even contacted.

Spectrum Defence Fund

I'm glad to see the RSGB has taken up my suggestion and opened a Spectrum Defence Fund to enable radio amateurs to contribute towards a legal challenge to the attitude of the UK authorities over interfering equipment such as power line networking devices. You can contribute by writing a cheque, payable to the 'Spectrum Defence Fund' and sending it to Spectrum Defence, RSGB, 3 Abbey Court, Fraser Road, Priory Business Park, Bedford, MK44 3WH.

I have written to the RSGB strongly urging them to make available a page where online donations can be made. This would allow websites such as this one to further support the cause by writing articles on the subject and publishing links to the donation page. I am sure this would result in donations from a great many people who would not otherwise be aware of the campaign, possibly even from outside the UK.

If you have a website and would be interested to support the RSGB Spectrum Defence Fund in this way, please write to the RSGB as well to support the case for an online donation page.

WSPR on 600 metres

The January 2010 edition of RadCom arrived today. In the letters column was a long letter by John Tuke GM3BST apparently complaining about those who advocate the use of WSPR on the 600m band instead of modes that involve two-way communication.

I felt this merited a reply. This is what I wrote:

I write in response to GM3BST's letter about WSPR on 600 metres. John says that "amateur radio has always been about communications between individuals or groups." I don't think that's true. I seem to recall that amateur radio began with "artificial aerial" licenses that allowed people to test transmitters without communicating at all.

Though two-way communication undoubtedly forms the majority of amateur activity these days there are still many for whom building and testing equipment or carrying out propagation experiments is the main interest. The medium is more important than the message, which these days can often be more effectively communicated via the internet.

Modes such as WSPR reveal a lot about propagation and their use probably contributes more to an individual's self-training than participation in the local club net. Transmitting a signal and seeing where it can be received is a tradition that goes right back to the first experiments by Marconi, and is therefore surely a part of our amateur radio heritage.

Friday, December 11, 2009

20m conditions

I spent an hour after lunch today on 20m PSK31 using the K3, 40W to the attic dipole, and KComm 1.8. I made seven contacts, all European. Despite the presence of a sunspot or two conditions seemed fairly flat. As usual, it was more interesting to see from the PSK Reporter website where my signals were heard rather than what I actually worked.

Although I only heard one station, VE2AHS, from across the Atlantic, I was heard by as many stations in the eastern USA as here in Europe. Why is that? Is PSK31 more popular over here, making QRM levels higher and weaker signals less easy to copy? Although I'm happy to work Europeans, it would be nice to make more Stateside contacts.

Preparing to build the SoftRock

I spent a couple of hours yesterday evening preparing to build the SoftRock 6.2 Lite kit that I hope to use as a panadapter for my K3. I started by printing out all the detailed build notes at WB5RVZ's SoftRock page. This describes building the receiver in seven separate stages, starting with the power supply and ending with the external connections. Each stage has its own bill of materials or components list, so I then checked the supplied components and put them into individual small polythene bags, one for each stage.

When I got to the local oscillator stage I realized that I didn't have a crystal. An email to the Elecraft reflector produced the information that the crystal used for the K3 panadapter version is a 32.768MHz. Even better, it produced an offer from Alan G4LWA to send me one he had that was surplus to requirements. Aren't hams a great bunch?

I'm also missing an unusual component, a 4.7uF ceramic capacitor listed in the operational amplifiers stage as Cxx with the note "for audio test". I can't see where on the board that goes and on a scan through the instructions I couldn't see any mention of it. I'm sure I have a 4.7uF electrolytic capacitor in my parts box which will hopefully do, but I think I'll have to solve this problem when I come to it.

I'm a bit apprehensive at building this kit. I'm going to take it very slowly, in stages, no more than one every few days, not least because I can easily set off my back problems by spending too long hunched over the desk which is necessary to see what I am doing using my magnifier headset.

There are about 4 SMT ICs to be soldered in, and ten SMT capacitors. At the moment, the capacitors look more scary than the ICs. I can't even see how to get them off the backing strip without them pinging off to be lost forever in the carpet. At least the ICs are big enough to hold on to.

Although building the receiver in stages makes a lot of sense, I'm wondering if it would be easier to solder all the SMT parts on first. I think it would be easier to do while I can put the board flat on the bench. As soon as any through-hole parts are on there they will restrict access and make it harder to keep the board in a stable position. I need to think about what is the best way to proceed before I can actually start.

Thursday, December 10, 2009

Receiving SAQ on VLF

Roger G3XBM has posted a reminder in his blog that the Swedish station SAQ will be making a special Morse transmission today on 17.2KHz VLF to celebrate the 100th anniversary of the Nobel Prize award to Guglielmo Marconi and Karl Ferdinand Braun.

As 17.2KHz is in the audio spectrum it should be possible to receive this transmission with nothing more than a computer sound card. And Johan SM6LKM has written a software defined radio (SDR) program that will do just that. All you have to do is download the program from his web page, unzip it to a suitable folder (it's tiny, and there is no installer) and run it.

You need to connect an antenna to the left channel of the sound card microphone input (the program uses the Windows default sound card.) I don't have a long wire or any other VLF antenna so I have just used the outer (screen) of the feeder to my attic multiband dipole. Check that you have enabled the microphone input and increase the volume slider to maximum. The program will tell you if the input level is too high. You should see signals appear that disappear when you disconnect the antenna.

You can then increase the output gain in the program itself until you can hear the background noise. I can hear a few warbly carriers near the top part of the spectrum, as you can see in the screenshot above, and the occasional burst of static, so I'm definitely receiving something off-air and not just locally generated noise. There's a button that will set the correct frequency for the SAQ transmission.

It's too late for the transmission that was sent at 0800UTC today, but another is scheduled for 1600UTC. I have no idea if it will be possible to receive it with such a simple setup and poor antenna but it will be fun to try. If you read this too late for that, then there will be another transmission at 0800UTC on Christmas Eve, December 24th. I'd be interested to hear if anyone manages to receive it using this program, and with what antenna.

New Hamsphere released

As someone who tried, out of curiosity, Kelly Lindman SM7NHC's VoIP ham radio simulation Hamsphere a couple of years ago, I received a notification that HamSphere 2.0 has just been released.

I haven't tried this new version and I'm still very aware of what happened last time someone blogged about something like this. Since no radio is involved, I find it hard to find any lasting interest in making "contacts" with it.

But in view of the gloom I presently feel over the UK government's attitude to the PLT interference issue, the fact that I received an email about this on the same day seems foreboding. I'm starting to wonder if amateur radio will soon be something like Sinclair ZX81 games or Space Invaders machines that we will only be able to experience via a simulation.

Another kiss-off for UK PLT fighters

It comes as no surprise to me to learn that the second attempt to use an online petition to force the UK government to outlaw home networking over power lines (PLT) devices has been given a diplomatic kiss-off, just like the first one. The government's response - which you can read in full here - concludes "On the available evidence, we do not believe an outright ban of all powerline equipment is justified."

The response was so predictable that I didn't even bother signing this petition. The online e-petition site exists simply to give the impression that democracy exists in this country and that ordinary people's views count. The results show what a lie that is.

The only things that count for anything in this country are money and votes. There are too few radio amateurs to influence anyone's electoral results. And as long as it is cheaper for British Telecom to solve reports of PLT interference by "
replacing the apparatus, hard wiring and conventional wireless alternatives" than to withdraw the offending devices, that's what it will do.

There were 121 reported cases of PLT interference in the UK in the last year, and according to the government's response 104 were resolved in the abovementioned manner. What the reply doesn't say is what happened in the 17 cases that were not resolved. It would appear that 17 UK radio amateurs are no longer able to pursue their hobby because of this.

The response also states that "
the Regulator’s investigations found no breach of the EMC requirements." If true, this suggests that the regulations aren't strict enough to protect the ability of radio amateurs and listeners to receive weak signals on the short wave bands.

We're all doomed! The steady increase in noise levels due to the proliferation of all kinds of electronic devices is something that most of us have experienced unless we are fortunate enough to live in the middle of nowhere with no neighbours. I seriously doubt that ham radio will still exist as a hobby in ten years' time.

Wednesday, December 09, 2009

Opportunity in obsolescence

Photography has never been a great interest of mine, nor have I ever had much of a knack for it. About ten years ago I bought a Kodak DC280 digital camera to take pictures I could email to friends or use on websites. It was a 2.3 megapixel camera that could create 1760 x 1168 images and cost, if I remember, an eye-watering £500. It is still working but wasn't used all that much and until recently I never had the slightest interest in replacing it.

After starting this blog I realized that it would be nice to have photos to accompany some of my postings. Because the DC280 is about the size and weight of a half-brick I rarely bother to take it with me on outings. Nor can it focus down very close so it can't produce nice sharp pictures of electronic bits and pieces. So I started thinking about finding a new, compact replacement with a good macro facility. But I didn't want to spend much money on it.

The local discount store Aldi had a Traveler brand camera for about £60 which was the right sort of price. But I could not find out if it had a macro facility and it had a ridiculous number of megapixels. I think the top digital cameras now are about 12 megapixels, while even budget models like this Traveler have 7 or 8Mp.

I really don't know why compact cameras used for holiday and family snaps need such a high resolution. The pictures they take aren't going to appear in National Geographic. They take up a lot more space on the memory card or computer hard drive and need to be reduced to fit the screen. What's the point? But whenever you talk to someone about digital cameras the first thing they ask is "how many megapixels has it got?"

I started looking through eBay and found a new Pentax Optio S30 for sale. Pentax is a good brand and the S30 had good reviews. It has 3.2 megapixels, a 3x optical zoom and a super macro mode that focuses down to a few centimetres. It was made in 2004, when it cost around £200. I assume that this one sat on a dealer's shelf for years until the firm went bankrupt or someone had a clearout.

I haven't had much opportunity to try it out yet, but this picture of illuminated reindeer in the grounds of nearby Armathwaite Hall on a typical grey Cumbrian day looks good enough when reduced to a suitable size for web viewing.

I tested the macro capability by taking another picture of my K3's cracked RF gain knob. As you can see, it's a lot clearer and sharper than the one taken by my wife's Canon Ixus. So I think the Pentax is going to be able to do everything I want.

The price I paid for this quality camera that lacks only a fashionably high megapixel count? Just £25, or one twentieth of what the Kodak DC280 cost a decade ago! The seller has 4 more left!

I found I can also save on accessories. The camera didn't include a memory card, and it can only take an SD card up to 1GB. All the websites advertising cheap 1GB SD cards were out of stock of the cheap ones. I decided 512MB would be enough for me, and was able to pick up a Camlink SD Camera Kit on Amazon for just £2! Yes, £2 for a 512MB SD card, a USB card reader, a desktop tripod, a lens cleaning kit and a camera case. There are 4 more of those left, too.

How quickly technology items become worthless, able to be sold only at giveaway prices. But if you aren't bothered about having the latest spec it's clear you can get yourself some bargains.

More hot air about global warming

I have been trying not to get too annoyed about the vast expense and amount of hot air being talked at the climate change summit in Copenhagen. But one thing I read yesterday made me really angry. There are proposals to cut the amount of flying by increasing air taxes and even by flight rationing. A British government minister apparently told a BBC reporter that an inevitable effect would be to make flying unaffordable for poorer people. And this from a minister in a supposedly "socialist" government!

Britain is an island, and unless you live in the south east within easy reach of the Channel Tunnel, flying is the only way to get out of the place. I am someone who likes to feel the warmth of the sun on my body, and flying is the only practical way to get to places where that is possible. It is also necessary for one's sanity sometimes to get away from English small town life and experience a different culture. In short, the ability to travel by air is a vital element of my quality of life and I will fight like hell if anyone tries to take it away from me.

I don't understand why the climatologists are fixated on air travel being the major cause of climate change. It seems to stem from a hair shirt environmental asceticism that demands that you suffer in order to achieve something. It may even have something to do with extremist left wing views that flying, like owning big gas guzzling cars, is something the rich do and must be stopped for that reason. Ironically, if flying and fuel are made more expensive, only the rich will be able to carry on doing it.

Figures you can easily find on the web show that the carbon emissions of a full modern aircraft, per passenger, are approximately the same per mile as that of a small family car. True, people travel longer distances by air, but most people also make air journeys far less often. Most of us cannot live in the places we like to visit on holiday so the flights we do make are essential to our well-being. But many people could live nearer work. So if the aim is really to cut carbon emissions why is nothing done to curb the unnecessary commuter journeys of people who drive an hour or more each day to and from the workplace?

The eco movement seems fixated on certain symbols of alleged waste yet fails to tackle the real problem. For example plastic bags are now considered bad for the environment. There has been talk of taxing them, and many supermarkets now charge instead of giving them free to customers. Yet the amount of plastic in a bag is only a fraction of that in the packaging of all the products that will be carried inside it. What is being done about that? Precisely nothing.

People are encouraged to turn off TVs, PCs and other equipment at the wall socket instead of leaving them, each consuming a couple of watts of power, on stand-by. Yet no-one seems to have realized that this often just isn't practical. Only a couple of days ago I bought a new radio tuner with wi-fi capability that can play audio from MP3 files on a server on my hi-fi system. If you switch it off overnight it forgets all its laboriously entered settings. Same with the DVD recorder - the clock resets to zero and it loses all the TV channels. If there was any joined-up thinking in government then surely by now the manufacture and sale of products that need to be left on stand-by would be illegal?

What about all the unnecessary waste caused by discarding electronic products because they are simply last year's model. My mobile phone company could not understand why I would not upgrade my phone, for free, after my 18 month contract expired, because the old one still worked perfectly and did everything I needed.

How many still-working computers have you thrown away just because they wouldn't run the latest version of Windows? There is nothing, NOTHING that I personally use a PC for that could not be done on Windows 95, were it not for the fact that many applications now require at least Windows 2000. But I definitely do not need Windows Vista or Windows 7. There is nothing they do that I need. But many people are convinced that they do and so vast numbers of perfectly functional computers, produced at a cost of vast amounts of carbon dioxide, are thrown away, worthless. Should people have to pay more for their holidays while waste of this nature still occurs? It doesn't seem right to me.

Regular readers of my soapbox rants will know I am a climate change skeptic. But I do, actually, believe that we should conserve the resources of this planet, and have done since long before the term "global warming" was invented.

However I think that any measures introduced to encourage conservation of resources for the good of the planet must be fair for all. The less well off and the undeveloped nations should not have to make the greatest sacrifices, and ordinary people should not have to pay more for their two weeks in the sun while so many other wasteful uses of energy continue unabated.

Sunday, December 06, 2009

Now I've cracked up!

Well would you believe it! When I posted "Cracking up" yesterday I was only concerned that the spate of reports of broken knobs on Elecraft K3s meant that there was something wrong with them and that I and many others would eventually become victims. I didn't think there was anything wrong with the knobs on my K3 serial number 222 at the moment. This morning, just for the heck of it, I put my magnifying headset on to examine the knobs more closely. The first three were OK but when I examined the RF/SQL SUB outer knob I could see a hairline crack going through the set screw hole from front to back.

You would never have known it by turning the knob but the crack is clearly visible (especially if you click the image above to see the full-sized version) and can be closed by squeezing the knob (which has now made it a bit loose.) I think this is a more extensive issue than most people realize, or than Elecraft is claiming. If you own a K3, check the concentric knobs with a magnifier. You might be as surprised as I was!

Dave G4AON just sent me a picture of the AF knob on his K3 after he removed and tried to replace it.

You don't need a magnifier to see the problem with that one!

Saturday, December 05, 2009

Cracking up

A few months ago there was a spate of complaints on the Elecraft reflector from new K3 owners that the front panel knobs had disintegrated. The knobs on the K3 are made entirely from plastic or some compound material and do not have a brass insert, so they are very vulnerable to over-tightening. According to Elecraft, the manufacturer of the knobs made a bad batch that was rather brittle. They are now making the knobs with a much tougher composition and these were sent to all those affected and are being fitted on all newer K3s.

That should have been the end of the matter, but every now and again another incidence of cracked knobs is reported. One Swedish amateur complained on the reflector rather rudely because after requesting a replacement it took eight weeks to arrive (not necessarily Elecraft's fault) but then to add insult to injury the replacement also failed. This morning Al, WA6VNN, who has K3 #31 delivered in November 2007 reported that his AF gain knob has failed, even though he took care not to over-tighten it when assembling the radio.

Because of this I expressed my concern that problem is not confined to a faulty batch as originally stated and that the K3 knobs may not last the life of the radio. Of course, this offended those who will tolerate no criticism of Elecraft. I received numerous emails on the lines of "My K3 is S/N #### and no knobs have failed" as though that proved there is nothing wrong with them. All it proves to me is that, like mine, their knobs haven't failed yet. I suspect it's more a matter of when, rather than if, they fail.

Someone even went as far as posting a picture of one of the cracked knobs on Flickr with the comment "What is all the fuss about?" Am I being completely unreasonable for expecting better quality knobs on a $3000 radio?

Eric Swartz of Elecraft replied rather grumpily to the latest complaints that the issue had been solved months ago and referred to an earlier posting where he explained about the bad batch and states that "we will replace any broken knob for free." But given the evidence that the knobs on any older K3 may break at some point, not just those from a duff batch, why should K3 owners have to wait until one does (perhaps at an inconvenient moment) before requesting a replacement, and then suffer days or weeks of inconvenience until it arrives?

My friend Dave, G4AON just checked the knobs on his K3 #80 and found the AF control was cracked. I think Elecraft ought to offer replacement sets of the new tougher knobs to all owners of K3s fitted with the original brittle ones. But after previous experiences, I no longer have the courage to suggest that on the reflector.

Between a SoftRock and a hard place

A couple of weeks ago I posted a message on the Elecraft reflector to the effect that if anyone was using a SoftRock SDR kit as a panadapter for the K3 and was planning on replacing it with the Elecraft P3 panadapter that is shortly going to be available, I was interested in experimenting with it and would give the SoftRock a good home. Craig, VK3HE replied that he had a kit which was mine for free if I would send my address. I thanked him very much, sent my address and a small jiffy bad with an Australian stamp plopped on to my doormat this morning. Thanks again, Craig!


What I hadn't expected, since I'd anticipated that someone would be replacing a SoftRock they'd built and used, was that "kit" meant it was an unbuilt SoftRock 6.2 Lite kit! Inside the jiffy bag was a polythene bag containing one of the most densely packed printed circuit boards I'd ever seen. There hardly seems space for all the components, which include a few SMT parts. This is going to be a baptism of fire for sure!

However, no building instructions were included. I guessed there was a PDF file on the web that can be downloaded and printed out, but so far I have been unable to find it. I went to the SoftRock Radio website and clicked on the Documentation link and bizarrely, it opened some pages about installing WordPress! This reminded me that during a couple of other wet weekends in the last couple of years I had toyed with the idea of building a SoftRock kit and couldn't even find on the website where to order one!

Google found some pages by Jack Smith that describe building a Softrock and even using it as a panadapter which are going to be required reading, but he doesn't mention where he found the instructions on how to build it. Hopefully one of my more savvy blog readers will help me out here. Otherwise I'll probably have to send Jack an email and ask where he found them.

Friday, December 04, 2009

Wi-fi interference

I have often complained about the increasing amount of radio interference and its effect on amateur radio operation. But it is not just ham radio that is affected. Other wireless devices are too. The latest problem of this type that I encountered concerns a wi-fi internet radio called the MagicBox IMP Adapt.

My wife and I enjoy listening to classical music. One day some time ago I was trying out some internet radio tuner software and discovered several stations online that played non-stop classical music with few announcements. One that I particularly liked was WCPE, TheClassicalStation.org from North Carolina. I wanted to listen to it through the hi-fi system instead of the computer speakers so I bought an IMP Adapter, a dedicated "internet radio".

The IMP worked fine for a year or so but the other day it started freezing at "Initializing network" and then apparently rebooting. I wondered if it needed a firmware update but none was available. I did a bit of Googling about the problem and discovered several interesting things about it. Apparently this and most of the other wi-fi internet radio devices on the market are not specially designed custom electronics as you might expect, but general purpose computers with ARM processors running Linux! And a group of clever people called the Sharpfin Project had developed a system to enable you to bootstrap later versions of the software designed for other models of internet radio, even though they are no longer available from the original manufacturer.

This didn't help me much, because in order to bootstrap new software on to the device I needed it to connect to the network, and it wouldn't. But I discovered that the firmware wasn't the cause of the problem anyway. As you can see if you take the thing apart, the little embedded computer has a USB socket on it, and plugged into that is a bog standard USB wi-fi adapter. Apparently the one used with the IMP Adapt falls over in the presence of the latest IEE 802.11n wi-fi signals, which are becoming increasingly common being supported by the free wi-fi routers being given out by all the major broadband providers.

When I first moved here, only geeks had home networks. I never even bothered encrypting or securing my wireless network as the neighbours are mainly retired people or had no interest in computers and the likelihood of them trying to hack into my computers seemed negligible. Today if you open the "view all wireless networks" window on my laptop you have to scroll down to see them all. Obviously my wireless adapters are struggling to receive my network's signal among all the competing signals. In fact, I've just ordered a pair of 10dB gain wi-fi antennas for my router.

But back to the IMP Adapt. I found that there is a simple and fairly inexpensive solution to the rebooting problem, and that is to replace the existing USB wi-fi adapter with a different model. There is no guarantee that any old USB adapter will work with the drivers in the IMP's Linux kernel. But I discovered that the Edimax EW-7318UG adapter will work. It's also cheap - currently £7.99 from play.com - so it was worth a try. I ordered one, it came this morning, I fitted it and now the IMP connects with no trouble and works as well as it did originally. I had an anxious moment as it didn't look as if it would fit in. But I found that you can remove the plastic cover leaving the bare circuit board and then it fits in perfectly.

Now that the radio had network connectivity I used the Sharpfin software to install a newer firmware that provides a few extra features. So now not only can I listen to WCPE The Classical Station on the hi-fi again, I can also control the radio using a web browser, and telnet into it and change configuration settings. I could even write programs using free software tools and run them on it. Not that I particularly want to, but it does show that the IMP Adapt really is a little Linux computer.

I expect a lot of these IMP adapters and others that use the same 802.11n-incompatible wi-fi adapter are thrown away because they don't work any more. If you come across one, it might be worth salvaging. I'm sure someone could think of other uses for a little Linux computer with a three line LCD display, a network interface and a stereo audio output.

Thursday, December 03, 2009

QRP To Go

For various reasons I haven't done much portable operating this year. But one of the things I like to do with my portable gear is put together complete ready-to-go stations. My memory is not too good these days and if I have to just pick the bits off a shelf when getting ready to go I'm sure to forget some vital component such as the antenna, key or a connecting cable.

Today I assembled a complete portable station to go based around the HB-1A QRP transceiver. The case is Technobag which I ordered from CPC. Annoyingly, the case did not have a foam insert in it although the catalogue claimed it is supposed to include one. Fortunately on the same day something I ordered from eBay arrived and the seller had used a large piece of foam as packing material. I cut it to fit the case and then made cut-outs for all the parts of the portable station.

The HB-1A is at one side at the bottom of the case. Next to it, standing on its side, is the Elecraft T1 antenna tuner. Next to that is the charger for the internal batteries (I modified the HB-1A to allow the batteries to be charged internally.) I wondered about including that, but this is quite likely to be the station I would take with me on holiday so it was convenient to put it in there. I can always take it out to save weight when going out for the day from here.

Above the HB-1A is a Bulldog BD-2 Mini-Key with magnetic base, which sticks firmly to the radio's steel case. I shortened the cable provided with it for convenience and put some vinyl tape over the base to help avoid scratching the radio's paint. Next to that is a BNC to binding post adapter for the antenna wire.

In the lid of the case held with Velcro fastenings are the antenna wire and counterpoise wire, and the cable to connect the T1 to the HB-1A. I normally forget that! The black net bag contains a pair of Sony headphones. All I need are a notepad and pencil, and that's that. A portable QRP station, all ready to go! A pity that winter's here, because I'm not fond of the cold and damp (yep, I'm a wimp!) and don't anticipate doing any portable operating now until Spring next year.

Stocking up the parts box

When I was young, in fact for many years even before I got a ham radio license, I used to build a lot of electronic projects from scratch, following articles in magazines. In recent years I have only built kits.

When I was a teenager living in Essex I would get on my bike and ride over to a radio shop in Westborough Road, Westcliff-on-sea which was run by a balding elderly guy, his wife and their long-haired hippie son who was a dead ringer for Jesus. I can remember their faces now like it was yesterday, though it must be 35 or 40 years ago I last went there. I would hand over my parts list and they would disappear into the back of the shop and come back a few minutes later with everything I needed. Out front they had boxes of surplus boards for a few shillings each and sometimes I would buy one or two and spend several happy hours reclaiming the components to fill up my parts box.

That shop eventually closed, as did the parts suppliers in Tottenham Court Road and Edgware Road London, where I started work, and soon the only way to get parts was to order them by post from suppliers like Cirkit and Maplin. Cirkit stocked a lot of parts useful for RF projects, but they eventually disappeared, while Maplin gradually reduced its range of RF parts to give more space over to "consumer electronics". Eventually, sourcing the parts for a radio project would typically involve ordering from several different suppliers because none of them had everything you needed. It was a lot more hassle than going down to the local radio shop with a parts list, and with minimum order charges and postage costs it also got expensive. So I lost my enthusiasm for home construction.

A few months ago I ordered something online from a firm called CPC, as a result of which they started sending me catalogues. It is incredible the range of products they sell, and at very low prices too. But I discovered that CPC is related to Farnell, a well known professional supplier of electronic components, and one of the catalogues had a big section of electronic parts. Because they are a professional supplier, cheaper components have to be ordered in quantities of 5 or 10. But the prices are so much cheaper than Maplin that this is not such a disadvantage.

I decided that I would put together an order for a basic stock of resistors, capacitors, inductors, transistors and so on that should be enough for several small projects. Deciding exactly what to order was the hard part, and I kept putting it off for weeks. It seems to me that a good topic for an article in one of the radio magazines would be "What to buy to stock up your parts box."

Eventually I made a list as there were a couple of other things I wanted to buy from CPC and it is worth ordering more than £40 worth of stuff at a time to avoid the small order processing charge. The order came this morning. I have organized the parts into separate polythene bags (they came packed in dozens of them) so I can easily find them.

Now all I have to do is start building something!

Wednesday, December 02, 2009

WSPR activity on 160m

Lots of WSPR activity on Top Band tonight. I thought I'd take a listen and so far have decoded 10 different stations from Norway to France.

I don't have an antenna for 160m so I'm using my multiband dipole that covers 80m, 40m, 20m, 10m and 6m. However the best SWR the K3 ATU can manage to get with this antenna is 10:1 so I daren't transmit. Most people seem to be running 10W which is a lot more than is normally used for WSPR on other bands.

I think 160m is an impossible band to operate when you only have a very small attic to put your antennas. But it is interesting to see what I can receive. Some of the stations I have received are coming in at good strength. The accursed local QRN is on sounding like car ignition interference spikes but the K3 noise blanker took it right out.

Unexplained behaviour

This morning I tested another VHF/UHF short stubby antenna, this time a genuine one from a Japanese manufacturer. Not a Diamond SRH805S but a Comet SMA501, which is currently being sold by Radioworld for £19.95.

The first thing I did was check it on my antenna analyzer, and I was satisfied with the SWR curve which you can see in the chart below. The antenna is pretty narrow band, as would be expected being very short, but it was tuned almost spot on 145.000 MHz, which is the centre of the 2m band over here. The Comet SMA501 is also specified for use on transmit on 70cm, but my analyzer doesn't cover that band so I couldn't check it so easily.

After that I put the antenna on the VX-8E. My crude test was to transmit on low power and watch the S meter on the FT-817 on the other side of the room. I had to disconnect the antenna and all cables from the 817 to get the meter to read below end-stop. In fact the reading was still end-stop using the standard Yaesu rubber duck. The SMA501 gave a reading corresponding to about S9. I then put the "dud" Diamond SRH805S on the VX-8E and you could knock me down with a feather! The signal strength reading was exactly the same!

For a comparison, I put my Elecraft DL-1 dummy load on the VX-8E. This is a dummy load that is not particularly well screened, comprising several resistors on a printed circuit board. The signal did not raise any bars on the FT-817ND S-meter at all. So both antennas are definitely radiating - the signal wasn't being picked up from the radio itself.

When I tested the SRH805S I noted that the SWR was near infinite, and the SWR curve showed the antenna was tuned for around 169MHz. The SMA501 is near perfectly adjusted. At 3:1 its SWR is a bit high but nothing a handheld transceiver shouldn't be able to cope with. I wasn't comfortable about the high SWR of the Diamond antenna and was sure that this was why it performed so poorly. In fact I suspected it of being a cheap Chinese fake.

Yet according to my FT-817's S meter both the fake Diamond and the real Comet radiate just as poorly as each other. Of the two I'd obviously be happier using the Comet which would be reflecting less power back into the VX-8E's PA. But I would have expected that to make the Comet more efficient and it doesn't seem to. I can't explain this.

Tuesday, December 01, 2009

Calibrating the FT-817ND

A week or so ago I downloaded the latest version of K1JT's WSPR software. It has a few interesting features including a facility to set your transceiver's frequency using computer control and a way to compensate for any frequency readout inaccuracy - important when you are working within a sub-band only 200Hz wide. The process involves measuring the error at various frequencies by tuning 1.5KHz below stations of known accuracy and measuring the frequency of the heterodyne. The program will then calculate and apply the correct offset for each amateur band. However a better solution if you don't mind opening up the case is to adjust the master oscillator in the transceiver so that the readout is spot-on in the first place.

I did this first with the K3, which was easy because the master oscillator is adjusted digitally using a menu. I then decided to calibrate my FT-817ND. The reference oscillator is accessed by removing the top cover. With the radio facing towards you it is on the left hand side. The trimmer you need to adjust is shown by the arrow.

I don't have the optional TCXO module which is rather expensive, but at shack temperature the standard oscillator seems pretty stable. However, the calibration adjustment is very touchy. The tiniest hint of movement can change the transmitter frequency by as much as 10Hz at 10MHz.

I tuned 1.5KHz below WWV on 10MHz and then adjusted the trimmer so the audio frequency of the heterodyne was measured as 1500.00Hz. Adjustment was an iterative process. The audio frequency might be 1497.35Hz, then I'd nudge it up to 1497.85Hz, then the next time it would go up to 1505.43Hz and I'd have to start nudging it back again. This went on for some time, getting within a fraction of a Hz and then overshooting by several Hz in my attempt to get it spot on and having to start again. I probably spent over an hour on this and was getting a bit frustrated by the end of it, but eventually I got to within 0.15Hz which is probably as good as you can expect with an FT-817ND.

The audio frequency is measured using the computer sound card, which is not a calibrated device, and I wondered if errors in the sound card clock frequency could make this calibration method invalid. I asked about this in the WSPRnet forum and Joe, K1JT replied: "If the crystal oscillator controlling your soundcard's sample rate is off by, say, 100 ppm then your measurement of a 1500 Hz audio tone's frequency will be off by 1500 * 100 / 1000000 = 0.15 Hz. It's a pretty lousy crystal oscillator that is off by more than that. There are many ways to test your soundcard's sample rate. All of them boil down to measuring a supposedly known audio frequency. One good method: put your radio in AM mode and use WSPR's "Measure an audio frequency" button while listening to WWV, during one of the periods when they broadcast a standard tone."

I can't receive WWV that well here and I have never heard it broadcast a continuous audio tone, so for the time being I'll accept Joe's assurance that my soundcard is unlikely to be out by more than the degree of precision that I'm able to adjust the reference oscillator to anyway.