Ultimate U3 beacon

It is here already.
Thank you very much, Konstantinos .
Now, all I have to do to find the yahoo group and sutable power suply.

New WSPR / QRSS beacon kit

Hans Summers (G0UPL) and Steve Farthing (G0XAR) have recently begun selling a new kit for a QRPp (150mW) beacon that can generate Hellschreiber, various QRSS modes and best of all WSPR. Unlike the ones now sitting unused in a drawer in G4ILO's shack which have my details programmed in, the Ultimate QRSS Transmitter Kit has a user interface with an LCD panel that allows you to input your own callsign, locator and power output. This means it has resale value - when you get bored you can sell it on and the new owner can program it with his own details.

At the moment, kits are only available for the 30m, 40m and 80m bands, though they can also generate an audio signal that can be used to drive an SSB transmitter.

I asked Hans if they were going to offer a version for 20m, which has become one of the most popular WSPR bands. His reply was that the kits will actually work fine on any frequency between 1MHz and 20MHz, they just require a different crystal and different components in the low pass filter.

A 20m beacon for WSPR would need a 14.097MHz crystal. I searched my junkbox and couldn't find one. Nor could I find a source for one and having one specially made would be expensive. Perhaps if there is enough demand for a 20m version it will be worth Hans and Steve's while to have a batch made which will be cheaper.

Propeller does WSPR

Through Eldon, WA0UWH I have discovered another blog to add to the blogroll: that of Jeff, KO7M. Jeff is interested in a lot of the same things I have been (including light aviation: an ambition of mine when I was in my 20s but which I could never afford to take up.) But what really piqued my interest was that he has just got a Parallax Propeller to generate a WSPR signal.

This is one of the things I was interested in trying. But I never got further than wondering how to implement the fractional frequency shifts of the WSPR signal, which uses 4 tones shifted by just under 1.5Hz from each other. Jeff has apparently found that a 2Hz shift is good enough to be decoded, allowing WSPR to be sent using the integer frequencies the Propeller chip can easily generate.

Once I have finished the Tiny Keyer project and can get back to the Propeller I will be trying this myself. My ambition at the moment is to make a multi-band multi-mode (OPERA, WSPR and perhaps QRSS as well) standalone beacon with an LCD panel to enable me to choose the band and mode. We'll see how far I get, but having two other people working on the same ideas should certainly make the task easier!

Operatic triumph

A new version of the Opera software has just been released which can output the bit code of a beacon signal so it can be programmed into a microcontroller such as a PIC or a Parallax Propeller chip. (You can find the download via the Links page of the Opera Yahoo group.)

I modified Eldon Brown WA0UWH's QRSS program code to send the bit code generated by the Opera software and it was received by my K3 on 30m and successfully decoded. Not bad for 5 minutes' work! You can download the code here.

Just as Eldon did I will have to build an amplifier to raise the output of the Propeller from a couple of milliwatts to something with a better chance of being received. Before it is worth doing that people will have to start using the Opera mode on the HF bands because with my antenna restrictions I have no hope of receiving or radiating a signal on LF or VLF. But I am quite excited at the possibility of building simple standalone beacon transmitters for this new weak signal mode which is much easier to generate than WSPR or QRSS.

Stop press: Just decoded G0NBD on 10.135MHz +1500Hz for my first real over-the-air Opera spot. And it appears my first transmission (using the PC software and my K3 at 5W) has been received by OM5NA at -21dB. This is fun!

First spin of the propeller

A new toy dropped through the letterbox today. It is a Gadget Gangster Propeller Platform USB demo board for experimenting with the Parallax Propeller microcontroller. If you haven't heard of the Parallax Propeller before then it is an inexpensive micro chip that contains eight processors called cogs (as in gear wheels) that can run independently in parallel. It's quite a bit different from the Microchip PIC or Atmel devices which have a single processor architecture similar to an ordinary computer.

 I sent off for the board just after Christmas, after reading about it in Eldon Brown WA0UWH's blog. Eldon posted code showing how the board could be used as a QRSS beacon. I was quite excited by the idea of a device that with simple programs even I could understand could be made to emit RF.

I sent off for the board on 27th December choosing the low cost untracked USPS air mail shipping option and it arrived today, 4 January - much quicker than expected. What's more, there were no nasty customs charges! Gadget Gangster still has a special offer of $10 off for the board, so if you fancy getting one of these to play with now is the time to do something about it.

I was very impressed at the speed with which Gadget Gangster processed my order. What you get, though, is just the board. You will need to provide a power supply (7.5 - 12V with a 2.1mm barrel connector, centre positive) and a USB cable with a mini-USB jack at one end. These seem to breed in my junk box so that was not a problem. You will also find useful a small breadboard and some hookup wire to attach components to the board and test your programs.

I installed the Propeller Tool - a free download from the Parallax website, connected the board to my Samsung NC10 netbook. I then tried the Blinky Light tutorial from the Gadget Gangster site. It didn't work - until I connected the LED the correct way round (stupid newbie error!)

Over the next few days I'll be working through the tutorials to get the hang of the system. Then I'll take a look at Eldon's QRSS beacon code and adapt it to send my own call. I'd like to make a WSPR beacon. I don't know yet if that will be possible, but I'm looking forward to playing with this Propeller chip and using it in some radio-related project. Watch this space!

Beacon of hope

These last few days have been surreal. I don't feel like a man with a time bomb in my head. I'm still weak, tired and find concentration difficult (the ability to get some decent sleep would help) but every day seems to bring an improvement in many functions. I'm even typing more accurately than I've done in a long time. I suppose it's possible this brain tumour was having an effect on things before I even became aware of it.

I'm far from feeling up to spending a lot of time on the hobby (or anything else in particular) but my mind still needs things to occupy it and my links and contacts with the ham radio community help lift my spirit. As I'm not using my magnetic loop antenna I thought I would connect up the 30m QRSS beacon I built last autumn. So my callsign will be going out over the airwaves as a sign that I'm down but not out and not giving in to the doctors' pessimistic predictions.

I'd appreciate reception reports direct to my email (julian . g4ilo at gmail . com). At the moment I can't make head nor tail of grabbers. Nor can I figure out how to change my entry on the Knights QRSS Clipboard. A long way still to go, then, but at least progress for the moment is in the right direction.

73 and thanks for all the messages of support. They really were appreciated during this awful week. If you are interested, you can follow my progress with treatment in One Foot in the Grave.

Spotted in Spain

My 30m 50mW QRSS signal has now been received in Spain by the grabber of EA1FAQ. (It's the one at 10140.030 kHz.)

That's a distance of 1458km or 906 miles.

[Off-topic note: When will Blogger fix its frigging "Add Images" uploader so it works in Firefox? I had to use the ghastly IE to insert the picture.]

QRSS success

My 30m QRSS beacon transmitter is working very well. It has been on the air for more than a day now and has been received in Italy, Belgium, Holland and the UK. This is a 50 milliwatt signal being radiated by a magnetic loop antenna in the attic! Isn't QRP amazing?

On Sunday I assembled the QRSS beacon into a nice case. This is not my favourite constructional task - give me toroids to wind any day! - but I do like the projects I build to look reasonable. The case I used was one I bought for the abortive 2m FM Fredbox project. I even used the SMA chassis socket I bought for that project as the case wasn't really suitable for a BNC socket and I didn't have any of the RCA phono chassis sockets I often use for QRP projects in my junk box.

This case has a compartment for a PP3 9V battery. I had toyed with the idea of using a PP3 battery and building in a regulator to reduce the voltage to the required 5V but space was tight and I was concerned that the heat given off by the regulator would affect frequency stability. Also with a current consumption of 70mA at 50mW output a rechargeable PP3 battery with a capacity of 280mAH would last for less than 4 hours between charges.

I observed that it is possible to squeeze 4 x AAA cells into the same space. Rechargeable NiMH AAA cells have a capacity of 1100mAH. Four of them will provide a voltage of 4.8 - 5.2V which will give 15 hours of operation and require no regulation at all. So that is what I will use.

Fitting the project into the box took a bit of time because it was a tight fit in the case. I had to be very careful positioning the antenna socket, switch and external power / charger socket to ensure they didn't foul any of the components. One of the frustrating things about boxing-up projects is that you can never find a case of exactly the size you want.

As I didn't have a suitable battery pack I started off powering the transmitter from the computer. I took a redundant USB cable, cut the end off, determined the +5V and GND leads and soldered a DC power connector to them. That got the rig on the air, where it was almost immediately spotted by PA0TAB. The stability of the transmitter is excellent. There is a slight drift down in frequency by 10Hz or so during the first few minutes of operation. After that it appears to be pretty steady. There does not seem to be any need to encase the crystal oscillator in insulating material or use an oven as some QRSS builders have done.

Later on I dug out a charger for a mobile phone which has a USB socket on it and I switched the power over to that so I could keep the QRSS transmitter on overnight after I had shut down the computer. Nobody spotted me overnight, but I will leave it on for a few days to see whether I can be received further afield than Italy. To be received on the other side of the Atlantic would be a great thrill!

Here is a selection of grabs from stations that received my signal in the last 24 hours:

I2NDT, 1356 km, 843 miles

ON5SL, 635 km, 395 miles

PA0TAB, 673 km, 418 miles

(Direct conversion RX, end-fed antenna)

G4CDY/A, 499 km, 310 miles

(FT-817, 1.5m loaded whip antenna)

On the air!

My QRSS beacon is now on the air, running 50mW into my MFJ magnetic loop in the attic. It is showing up very well right now on the grabber of PA0TAB.

I also saw it less strongly on the grabber of I2NDT, but I forgot to grab the image before it faded into QSB.

Reception reports will be most welcome to:

Bricked chip

Last night I received an email from Steve G0XAR to let me know that a replacement chip for the QRSS beacon had been programmed but not posted yet as he had been ill with a bad cold. However my impatience had got the better of me and I started wondering whether I could reprogram the chip myself. Perhaps this was the opportunity I needed to start playing with microcontrollers? The source code was on Hans G0UPL's website, the development tools were all free. All I would need is a programmer, and I was sure I had seen circuits for microcontroller programmers knocked up from junk box parts on the web.

A bit of searching revealed that simple programmers for the AVR ATtiny13 chip can easily be made, such as this one built by Alan, VK2ZAY, but they require a parallel port, an antique piece of hardware that went out of use around the time Bill Gates made his first billion and is now as obsolete as the USB port will one day surely be.

However I also came across an article that described how to program AVR microcontrollers using a Microchip PICkit2 programmer. A couple of years ago I obtained a PICkit2 because it was being offered in an electronics magazine for just the cost of the postage. Apart from running a couple of demo programs I had never done anything with it. What more of an excuse did I need?

In less than an hour I had downloaded and installed the AVR Studio software, WinAVR which was also needed, PK2AVRISP (the program which makes the PICkit2 look like an AVRISP or STK500 programmer), soldered six short leads to a 6-way header to attach to the PICkit2 and wired up the connections to the chip on my solderless breadboard. I already had a pair of virtual serial ports set up on the shack PC to use with the TrueTTY packet TNC so I was good to go.

PK2AVRISP detected my PICkit2 and I assigned it to one of the pair of virtual serial ports. The QRSS keyer program compiled in a couple of seconds and I was ready to program the chip. I selected the AVRISP programmer on the other end of the virtual serial port pair. The programmer read the signature from the chip and reported it was correct - an encouraging sign. Then I wrote the hex code into the flash memory. The write appeared to work but the verification failed with "WARNING: FLASH byte address 0×0006 is 0xFF (should be 0xCF)."

I searched forums for solutions to this error and tried various suggestions such as reducing the SPI clock speed or trying the STK500 option but I could not get past this error. One person claimed that he had somehow managed to program the chip despite the error so I put it back in the QRSS keyer, but now I just got a steady carrier with no keying at all. Oh dear!

I tried programming the code again this time using the avrdude command line programming software which is included with WinAVR but can't be run directly from AVR Studio. This appeared to work, no error was displayed when the code was verified, but the chip still did not work when put back in the keyer.

To avoid moving the chip back and forth to test it after each programming attempt I tried programming a simple LED flasher into it so I could test it on the breadboard (hence the LEDs in the photo.) This works fine if I simply ignore the flash verification error. So the chip isn't bricked. But why the keyer program doesn't work is a mystery. I assume it should flash the LED on pin 3 in time with the keying, but it doesn't.

Obviously a new chip will get the QRSS keyer working again but having spent all this time on trying to do it myself I would like to know why I couldn't. Usually when something doesn't work it is because I have made a stupid error, but I can't see what I have done wrong. It's so frustrating.

QRSS beacon progress

Yesterday I finished building the QRSS beacon kit board. The keyer chip sends the wrong callsign but it that was no reason not to build the kit. It's a very easy kit to build although there are no fewer than five toroids to wind which is a lot for such a simple project. Some people hate winding toroids though I find them easy to do and can't see what all the fuss is about.

The only other slight difficulty with the  kit is that the potentiometer for setting the output power has leads that are too big for the holes in the PCB. This is mentioned in the instructions, where it is recommended to use component lead offcuts to extend the originals. My junk box was supplemented a few months ago with a Maplin bargain pack of assorted potentiometers and lo and behold it yielded a wirewound trimpot of exactly the right value that perfectly fitted the PCB holes. So I used that instead.

When the board was finished I powered it up using my bench power supply and PM20 QRP absorption wattmeter. In the photo I have breadboarded a regulator from 9V down to 5V as I was toying with the idea of running the beacon from a rechargeable PP3 battery (the board will fit into a case I have which has an integral PP3 battery holder) and wanted to see how much heat the regulator would dissipate.

I found that I could get a maximum of just under 100mW from the beacon with about 120mA current drawn. This is a little less than the specification. The instructions suggest that a bit more than 100mW should be possible, but the shortfall isn't enough to worry about. For longer battery life I will run the beacon at 50mW which draws a current of around 65mA.

To get the transmitter on frequency and set up the mark/space frequency shift I used my K3 and QRSS VD software. The signal, even on the dummy load of the power meter, was very loud which was helpful getting it into the ball park. I had to disconnect the antenna, switch in the attenuator and back off the RF gain to reduce the signal to a level where I could fine-tune the frequency and see what the signal would look like on the air.

And here it is, sending G4LIO! It's a bit frustrating not being able to connect it to an antenna and put it on the air because of the wrong callsign. I've been promised a new chip and I practically snatched the post out of the hands of the postwoman but it hasn't come yet. In the meantime I can think about putting the beacon into a nice box. Forget winding toroids, for me that is the hardest and least enjoyable part of any constructional project!

Grab me a callsign

While I wait for a correctly programmed chip for my QRSS keyer kit I thought I would investigate the receive side of QRSS beaconing. It's no good transmitting if nobody receives, and unlike WSPR every transmitter isn't automatically a receiver during its off periods. This is a mode where you need to give as well as take, to receive in order to be heard, otherwise you can't complain if no-one tells you that they heard you.

QRSS signals are decoded visually using a spectrograph, a waterfall display similar to that found in digital mode software. However, you can't use a digimode software waterfall for two reasons: it moves too quickly - to capture a full callsign in QRSS you need to be able to see at least a couple of minutes worth of transmission - and it scrolls down vertically so trying to read calls would give you a crick in your neck!

Fortunately there are programs that have been specially written for just this application - and they are free so there is nothing to stop you trying them. The most popular program for Windows appears to be Argo. However there is alternative called QRSS VD by Scott Harden (the odd choice of name becomes clear when you realized that Scott's call is AJ4VD.) QRSS VD has one problem: it is a CPU hog. On my fairly modern shack PC it runs at about 50% CPU utilization. For that reason, you might have no alternative but to use Argo. But if you can run QRSS VD it has some nice features that add to the enjoyment of this aspect of the hobby.

QRSS VD includes three programs: a Spectrograph, a Viewer and a Grabber. The QRSS VD Grabber automatically captures the live waterfall and creates images suitable for uploading to a website so others can see whether you are receiving their signals. It doesn't have any way of automatically uploading the images to the web server, though. It's really for people who want to run an online grabber, which is only worth doing if you are going to run it regularly. I don't have enough radios and antennas to do that so I probably won't investigate this feature further.

QRSS VD Spectrograph is the program that displays in real-time what you are receiving. It has no obvious user interface - you have to right-click the window and then you will get a menu of options. One option lets you select the sound card that is connected to your radio. Another is for setting the frequency. The main settings option determines the size of the window and the maximum and minimum frequencies that are displayed.

There is also an option to save these settings. If you don't, you will have to set them all over again the next time you start the program. Finally there is the Resume option which you must click to start the spectrum display working.

Most QRSS activity takes place on the 30m band, in the first 100Hz above 10.140 MHz. This is just below the 200Hz used by WSPR, which is itself just below the region where PSK31 operation takes place.

To start receiving QRSS, set your receiver to USB mode and tune it to 10.139.000. If your rig has a DATA mode that is USB you can use that. Don't be tempted to use the CW mode - most rigs add an offset to the displayed frequency so it shows the frequency in the centre of the CW filter passband, and some rigs use LSB for CW, so finding the right spot gets confusing.

Select the sound card in QRSS VD, then set up the settings dialog. The window width in pixels can be whatever suits your screen size. The bandpass low and high settings define the height of the window, the minimum and maximum audio frequencies displayed on the spectrograph. With the radio on 10.139.000 USB, signals in the QRSS sub-band will be heard at audio frequencies of 1000 to 1100Hz. I set the low and high values to 950 and 1150Hz respectively to give a 50Hz margin on either side. (Note: if you aren't sure of your receiver's accurate calibration you might want to choose a wider margin initially because you could miss the QRSS band entirely of it is more than 100Hz out.) The other values on this dialog are all defaults.

[If you are interested in receiving WSPR as well, you could tune the radio to 10.138.700 and enter low and high values of 1250 and 1450Hz. Then you could run WSPR and QRSS VD on 30m simultaneously.]

Right-click the spectrograph window, click Resume and the screen should start scrolling to the left and filling with received signals. Conditions are pretty poor at the moment so there isn't much to see on the screenshot I made, but when I first tried this program I immediately received a trace of a signal from Steve, G0XAR who coincidentally is the producer, together with Hans G0UPL, of the QRSS beacon kit I just bought. I don't know if he was using one of these kits but it was producing a heck of a signal. (Ignore the frequency shown, this was received using my K2 whose calibration is considerably out.)

What's nice about the QRSS VD software is that you don't have to watch the output in real time to capture signals and it is simple to produce nicely formatted records of signals received like the one above. Every few minutes the spectrograph dumps a bitmap file in the program's Output folder. When you want to see what you caught you start up the QRSS VD Viewer, select a group of bitmaps to view and it will stitch them into a seamless time continuum. You can then scroll through from start to finish looking for the traces of QRSS signals.

When you find one, you can capture a region of the spectrograph by clicking to specify the top left and bottom right of the desired area. You can even specify a custom caption. The selected area is then copied to the Windows clipboard and pasted into your default bitmap viewer ready for you to save in a format of your choosing (for example, as a JPG file.)

Why would you want to do this? As I mentioned at the beginning, there is no way of finding out how far your signals got (apart from a handful of online grabbers) unless someone sends you a signal report, so if you receive someone's beacon you should send them a report too. The only way to do this is to look up their email address at qrz.com and send them an email. A picture is worth a thousand words, so it's nice to be able to send a screen grab of their actual signal as an attachment to the email.

If my initial experience is anything to go by, this personalized way of sending signal reports makes for a very friendly aspect to the hobby. I sent this capture (above) of a beacon from IQ2DP with an emailed report. This morning I received a nice reply from Teo I2RIT thanking me for the report and telling me all about the beacon, which is made from junk box parts and runs well under 100mW into a ground plane made of scrap aluminium tubing. He also sent a link to an article about it. The article is in Italian but here is a translation. If you've read this far then you will probably find it interesting. Yet another facet to our amazingly varied radio hobby.

QRSS Keyer

I have operated most of the reverse beacon and weak signal modes but one that I have never tried is QRSS. "QRS" is the Morse Q code for "send slowly" so QRSS means send very slowly indeed. QRSS beacons send your call using very, very slow Morse, which listeners receive using a "grabber", which is a slow moving waterfall display. If you're lucky, they will email you a reception report, but you can also look for your signal yourself on one of the various online grabbers.

One day I planned to build my own QRSS beacon. When I found out that Hans Summers G0UPL had produced a QRSS beacon kit I was disappointed to learn that all the kits had been sold at the US Dayton hamfest. However I recently discovered that he had made a new batch of kits and not wanting to wait and find out they were all sold at the G-QRP Convention I ordered one at the weekend. The order process was extremely professional (amateur components suppliers who expect you to email your order and credit card details please note) and the kit arrived this morning.

I opened the envelope and was very impressed to find that the package included a printed copy of the instructions as I had expected to have to print them myself from the website. The PCB is of very high quality. But as I tipped the parts on to the workbench my heart immediately sank.

Because the microcontroller chip which keys the transmitter and has been preprogrammed with my callsign was wrapped in a slip of paper on which was written G4LIO, a transposition of my call that often afflicts people on the air as well - I don't know why. The incorrect call was also written on the jiffy bag the kit came in. I checked the emailed copy of the order and the mistake was not mine.

After an exchange of emails with Hans I installed the chip in its socket, applied power and connected an earpiece to pin 2 which produces an audio tone to verify whether the chip had been programmed incorrectly. It sent G4LIO. :-( Why is it always me that gets the kits with the missing or faulty parts?