Iler progress

The Iler 40 QRP SSB transceiver kit proceeds apace - a snail's pace. I wasted a lot of time correcting stupid errors - like soldering a resistor in the wrong place and putting a diode in back to front. I mean, I know diodes have to go the right way round and the banded end is clearly enough marked on the board. Removing parts from boards with plated through holes is a nightmare. Why didn't I check it?

Part completed Iler 40 board

Another reason for the slow progress is that building circuits does my back in. It's the bending forward to see the parts under the magnifying lens that does it. Eventually there is a twinge from my lower back that says: time to take a break. So I'll put everything to one side and do something else for a bit.

Solder fume extractor

If you were wondering why you hadn't seen any more about the Iler 40 transceiver kit I bought then here's the reason. First I was distracted by making contacts using the new JT9-1 mode. But I also decided to get a solder fume extractor so I have been waiting for that to arrive.

It's probably a bit late in the game to start worrying about the carcinogenic effects of flux and lead solder fumes. But as the price of peace of mind was only £20 on eBay, I thought "better late than never" and decided to get one.

I was a bit surprised by how big it was. I was expecting something more the size of a 12 volt computer fan. But it sits nicely on the filing cabinet next to my drop-down workbench. I just have to think of somewhere to put it when it is not in use!

Iler 40 arrives!

It took its time getting here, but the Iler 40 QRP SSB transceiver kit from Spain has finally arrived! Opening the package confirmed my expectations that this is a very high quality kit indeed.

Iler 40 kit contents

The printed circuit board is top quality and screen printed with plated through holes. Quite a contrast to some kits of UK origin that look as if the board has been etched and drilled in someone's garage.

The components of each type are individually bagged. The CD containing PDF manuals in both English and Spanish has a custom colour printed label. A quick glance inside showed that the assembly instructions have been professionally produced and are of the a similar standard as the manuals for kits by Heathkit and Elecraft - if not better. Javier has even included data sheets for all the active components making this the most fully documented kit I've ever encountered. I'm going to enjoy building this.

It's going to be a while before I can get started, though. There are some major home improvements going on at the moment chez G4ILO and with all the hammering and sawing I'll have to wait for a peaceful and relaxed atmosphere. I also need to print off a copy of the 39-page assembly manual so I can cross steps off as I go along - and as you may have read our printer doesn't want to play ball.

A 40m transceiver kit

It has been a while since my soldering iron has been warmed up and I have been feeling the urge to build something. The challenge of building something from scratch has usually proved too much, so I have decided to build a kit. I've read a lot of good things about the "Iler 40" and its 20m brother so I decided to get one.

Iler 40 transceiver (EA9GCY photo)

I thought that this kit was sold on Ebay but a search for "Iler 20" came up blank. A more generic search produced some interesting hits including this 40m transceiver kit from a UK seller. This kit is quite a bit cheaper than the Iler kits but without any reviews it is a bit of an unknown quantity. I eventually found that the Iler kits can be bought from the maker's own site. The excellent reviews plus a higher output (4w vs 1w) were the decider. I was a bit unsure of which version to go for but I eventually plumped for the 40m version. More to follow once it gets here.

Spot on

A few days ago a package arrived from the USA. Fellow bloggers Eldon, WA0UWH and Jeff, KO7M sent me a Parallax Propeller board with one of Eldon's TCVCXO modules on it. I'm very grateful to Jeff and Eldon for sending this board as I'm not up to making something like that at the moment and as I found a few weeks ago the oscillator on the Propeller prototyping board is not thermally stable enough for WSPR use.

After a few modifications I installed my WSPR beacon code on to the board and this was the result:

My signal was spot-on frequency and there was zero drift. I let it run for several transmit cycles and there was a change of just 1Hz as the components warmed up. I am more than satisfied with that, so hopefully there will be more progress with the beacon project in due course.

OAFS redux

A couple of days ago I decided to take another look at the Spectrum Communications Off-Air Frequency Standard (OAFS). It had been suggested that its failure to work might be the result of a solder bridge or similar error. I had a good look at the board using a high power magnifier and found a pair of pads that were suspiciously linked to ground. A moment's work with the desoldering braid and sure enough there was a solder bridge exactly the width of a PCB track.

Having found a fault I was optimistic that the board would work. The setup adjustments were completed OK. But instead of hearing BBC Radio 4 in the speaker as the instruction sheet suggested I received a loud heterodyne with some speech faintly in the background, like listening to an AM signal in SSB mode with the BFO a couple of kHz off-tune.

I was looking at the Spectrum Communications advert in Practical Wireless to check how the ferrite rod was mounted and noticed that the description said "Background heterodyne whistle at 2kHz confirms lock condition." That is exactly what I was getting. Odd that the instructions didn't mention it though. Nevertheless I gave a cheer and went ahead with installing the board in its box.

My happiness was short-lived when I put my frequency counter on the output. It was 10MHz sure enough, but it was not phase locked to anything. I was only receiving the output of the uncontrolled 10MHz crystal oscillator which could be tuned a few tens of Hz either side of 10.000MHz. No adjustment I could make would cause lock to occur.

Comments made to my original post about this suggested that I might have problems with the OAFS as I am not in a good location to receive a strong signal from BBC Radio 4. I'm unhappy with the amount of time I've wasted on this. I think it would be best to write it off and forget about it. I'd rather not be bugged by it or have it taking up scarce space in the G4ILO shack. If anyone would like to have it and see if they can make it work then it's yours for the cost of the postage.

FreeTrak progress

I have made some progress with the FreeTrak PIC based APRS tracker. I found a slightly newer version of the PICFlash programming software. At first this gave exactly the same warning message as the original version. But after a bit of random clicking I tried again and this time the software reported that it was writing to the chip. It verified OK as well. I don't know exactly what I did, but at least that hurdle was now passed.

FreeTrak configuration

I set the DIP switches on the EasyPIC board to link the PIC pins used for serial I/O to the serial output. That didn't seem to work the first time, either, but at the second attempt at powering up I saw the configuration prompt appear in the terminal window. I was able to complete the FreeTrak configuration with the PIC in the development board.

Next, I changed a DIP switch to put the chip in Run mode. Using a utility called NMEAGen I began sending simulated GPS messages to it using the same serial connection I used for configuration. The LED began flashing at 1 second intervals and using a crystal earpiece on the output pin I could hear the familiar sound of 1200baud packet bursts. I don't know why it appears to be transmitting at 1 second intervals, but perhaps it is something to do with the simulated GPS data.

FreeTrak schematic

So FreeTrak appears to be working. All I need to do now is build it on to a circuit board and attach it to my GPS module and a radio. Here's where I could use a little help from readers. The AFSK audio output of the FreeTrak uses an obsolete op-amp which is unobtainable. I presume I could just replace this with a simple transistor amplifier stage using a 2N3904 or similar, but do I really need anything at all, given that the audio will drive a sensitive microphone input? Could I get away with just a DC blocking capacitor and a trimpot to set the level?

The other thing I'm unsure about is how to interface the FreeTrak to my GPS module. I think the circuit shown is intended to work with GPS devices that use 5V TTL or even RS-232 signal levels. The data sheet for my bare GPS module states quite clearly that the absolute maximum voltage on any of the pins is 3.3V. The serial lines on the PIC measure close to 5V. How to connect them?

Mistaken identity

A couple of weeks ago I came across FreeTrak, a PIC based APRS tracker developed by N0QBH. I have wanted to build a small 'grab-and-go' tracker for a while now. The FoxTrak works fine but is too big and bulky by the time it is paired with an HT. The TH-D72 is too much hassle as I need strong reading glasses to see the LCD screen and inevitably go out with some essential menu option disabled. Consequently these days I rarely bother taking APRS with me when Olga and I go for a walk around town.

I sent off for a couple of PIC 16F628A microcontrollers, thinking that I could program them in my EasyPIC5 development board. But when I tried, I immediately hit a snag.

My PICFlash programmer detects a PIC 12F508 instead of a PIC 16F628A.

I don't think I've been sold a fake MCU. If I remove the 16F628A so there is no micro plugged in at all I still receive the same warning. So I don't know what to do. I've bricked too many PIC chips by programming them with the wrong settings to try crossing my fingers and clicking Yes. So it looks like my FreeTrak project is not going to get off the ground.

Prop drift uncovered

Yesterday I wrote that I was shelving the Propeller beacon project after discovering that the frequency stability is unacceptabe. Eldon WA0UMH persuaded me to try some tests to identify the cause of the drift. My conclusion is that it is a combination of factors.

The major factor causing the drift is the power supply voltage. Whilst developing the beacon using just the Gadget Gangster board I was powering it with a 6V supply - the minimum needed. After adding a PA I needed to increase the supply voltage to 9V. The drift is greater with 9V, regardless of whether the PA is actually connected.

Looking down on the Propeller board

 If you look down at the Gadget Gangster Propeller USB board there are two SMT chips to the left of the Propeller and its clock crystal which appear to be voltage regulators. There is a 5V regulator a few millimetres to the left of the 10MHz crystal and a 3.3V regulator below it. The greater the supply voltage, the more heat the 5V regulator has to dissipate. Plugging the LCD UI board on top of the Propeller board traps in more of that heat making the drift even worse. This is not the first time I have discovered that voltage regulators and crystal oscillators don't go well together.

Whilst it is useful to know what is causing the drift, my discovery has not indicated an easy solution. Either I use a temperature compensated 10MHz crystal oscillator as suggested by one of my readers, or I use the Prop to control an outboard and more stable synthesized oscillator. The first option looks the easiest, but the TCXO is not an inexpensive component.

Propeller programming problems

Eldon WA0UWH posted yesterday on lessons learned about the Parallax Propeller programming language Spin. I too have been having fun and games trying to create a user interface for my multimode multiband beacon using the LCD module. Whilst some of my problems have been due to my failure to spot my own stupid mistakes, a couple were caused by the tools themselves.

A considerable amount of time was wasted recovering a working program after a change I made seemed to have messed it up. Eventually I discovered by accident that the program fails to run correctly on the Propeller board unless the main Spin source file is the foremost one in the Propeller Tool editor. I had begun splitting my code into separate objects with their own source files and because I had been editing or referring to one of these files I had tried running the code with one of these files in the foreground instead of the main one.

I wasted a couple of hours trying to backtrack what I had done and ended up installing one of those programs that archives each version of a file whenever you save it so that you can roll back to a previous state. The best program I have found for this is AJC Active Backup which comes with a diff tool that shows the differences between two files but unfortunately I have lost the licence key since the last time I installed it so as I was feeling tight-fisted I had to use something less good.

The other problem that caused a lot of lost time was an apparent error in the LCD UI Spin object. Specifically, the cursor method that is supposed to let you change the cursor to a flashing underscore or block just seems to clear the LCD and then crash. I had been hoping to use the cursor to show what bit of information the user was editing but I can't get it to work.

I'm not sure exactly where I am going with the beacon project. Jeff KO7M has developed a WSPR encoder that generates the required code when you input your call, power and locator. However there is not much point in using it unless I provide an interface that allows you to input this information as text. If I choose to support Opera then the bit code will have to be programmed in as no-one other than Opera's programmer knows the algorithm used to encode the callsign. As my beacon is unlikely to be used by anyone other than G4ILO in IO84 at however much dBm it produces I may as well hard code all beacon texts.

The other thing I'm not sure about is how to add the PA. The LCD UI module is now plugged into all the headers on the Gadget Gangster board and I don't want to attach wires to the board itself. I could solder headers to the two rows of holes adjacent to the existing headers on the Gangster board and then plug a board to the bottom of it. That would be the probably be the neatest solution - unless anyone has a better idea?

Propeller crash

Yesterday I had another of those days that nearly made me decide to hang up my soldering iron for good. Some readers may have spotted the despondent blog post I made before I deleted it.

I assembled the Propeller LCD UI module. It went together easily and I had no trouble with the soldering using a magnifying lens (a strong pair of clip-on reading glasses clipped on to my normal reading spectacles) and resting my soldering hand on the desk to stop the shakes. But Murphy was not going to let me get off that easily.

Preparing to test the UI board I realized that I had skipped a page of the instructions and had not soldered a connector to the LCD daughter board. I thought that a connector for the main board  (a male 8 x 2 box header) had been omitted from the kit so I had installed one of my own. When I picked up the daughter board I saw the two rows of 8 holes and without thinking installed the 8 x 2 plain header that came with the kit. Also male. When I realized my mistake bad words were said. In all my years of kit building I have never before done anything quite so stupid.

I recalled Don Wilhelm W3FPR's advice to K2 builders who install multi-pin connectors on the wrong side of the board to sacrifice the connector and not try to remove it intact. This I eventually did with Olga's help. She suggested I place the soldering iron body along the row of soldered joints to melt all of them so the connector would fall out. That didn't work, but it did soften the plastic part of the connector allowing it to be pulled away. I could then remove each pin one at a time and clean up the through holes using one of Olga's sewing needles. Finally I was able to install the four 1 x 4 female headers that had presumably been supplied with the kit as a replacement for an 8 x 2 female that was really needed.

After all that stress (both to me and the board) I was relieved that when I plugged it in to the Propeller board and ran the demo program the UI module worked. But my happiness was short-lived. After I tried some modifications to the program I found that it seeemed to be crashing. The program would start at switch-on but would eventually hand up and not respond to the buttons. Sometimes garbage appeared on the LCD. The time before this happened got shorter with each attempt until sometimes the Propeller wouldn't even respond to the reset button. I restored the original program in case my changes were to blame, but the device was still crashing.

Next I re-heated all the solder joints I had made, though they all looked OK. On reassembly the Propeller still crashed. Thoroughly despondent by this point I typed a post describing what happened in the hope that someone would offer to come to my rescue (thanks to those who did.)

After a rest it occurred to me that I had crashed the Propeller by dropping the board a centimetre or so on to the desk. There was probably still a bad connection somewhere. I re-soldered all the joints, including all the ones on the main Propeller board. That had been ready assembled. I guess that the manufacturer had used lead-free solder because I couldn't melt the joints until I applied a bit of my own leaded solder to each one. Then all the joints looked nice and shiny.

After that treatment everything worked and up until now, cross fingers and touch wood, has continued to do so. So it seems that a poor soldered joint in the manufactured board was the cause of my problem! Thank you, Murphy, but I don't need your help. We do this for fun, do we?

Now output

Everyone who commented to my last post about the lack of output from the Kits and Parts RF amp felt that the problem had to be the QRPer's curse - the toroid inductor. Normally I don't have a problem with toroids, but when they are so small that your thumb obscures the whole core while you are holding it, never mind winding it, they are not the easiest of components to work with.

So I gritted my teeth, tried to forget the hour I'd spent yesterday wrestling the thing into position, and yanked it out. One of the wires broke off in the hole leaving nothing to grab on to. I was unable to clear the small plated-through holes in any case. What I was able to do was melt the solder enough to push some bare wire through, creating "pins" that I could solder to. I twisted together the two wires that are connected so I had three ends to solder to the three pins I created. The toroid now stands up on the board a bit but it was easier soldering to the pins than trying to get four thin wires to go through four holes simultaneously. To my joy, on applying power and RF the power meter showed output.

I'm getting about 150mW if the amp is supplied with the recommended 8V, and just about 200mW from a 9V supply. That's only about 10dB of gain, a bit less than expected but probably enough given that the Propeller does not generate the purest of signals. The WSPR beacon has already been spotted a few times in Germany. But the 2N5109 runs a bit hot to the touch so I'll have to QRT until the heatsink I ordered arrives. In the meantime I still have the LCD UI board to assemble and play with.

No output

I built the Kits and Parts RF Amplifier. Unfortunately it didn't work.

When power is applied the meter in my bench power supply reads 0.01A. As soon as the Propeller beacon starts the current draw increases to 0.03A (at 8V). But the needle on my QRP power meter, which shows more than 25mW from the barefoot Propeller, doesn't budge.

I don't understand it. It's a simple enough circuit, there isn't anything to go wrong. Unfortunately I find these kit construction failures too demoralizing. I struggle with my vision and shaky hands just to build the board. Desoldering and faultfinding are beyond me at the moment. If I do discover the cause of the problem it's something really obvious that anyone with a normally functioning brain would spot. I think it is time for me to accept my limitations and stop attempting to do what I used to be able to do before my brain surgery. From now on if I can't buy what I want ready to go out of the box I'll just have to do without.

Under the microscope

A couple of weeks ago Jeff KO7M wrote that he had acquired a binocular microscope for the workbench to enable him to work with SMT components. Although I have no particular desire to do SMT work at the moment I do have trouble with close-up work due to my eyes' limited focal range and becoming very far-sighted. So I thought a binocular microscope would be a good addition to my workbench too.

Jeff wrote that his binocular microscope was not cheap and from the look of it I would imagine the cost ran well into three figures. The one I got was £30 from a firm that disposes of liquidated stock on eBay. I'm sure it isn't as good as the one Jeff got but hopefully it will be useful. If not I can always start another hobby looking at plants and insects or growing bacteria!

Some assembly required

Yesterday a packet from the USA dropped on to the doormat. It was the LCD UI module from Gadget Gangster. The cheap international shipping option is pretty quick!

LCD UI module ready for assembly

On opening the envelope I was taken by surprise as I hadn't realized the module was a kit. But there aren't too many components and they are all through-hole so I should be able to manage it. I will take my time and double check everything to ensure I don't do anything stupid like solder headers on the wrong side of the board. More than a few K2 builders have done that!

The instructions on the Gadget Gangster website are very comprehensive with several colour photos showing different stages of assembly. But on checking the parts against the parts list I found that I was missing one 2x8-pin header socket. Fortunately I found one (a pack of 2 actually) for a couple of quid from a UK based eBay component supplier so I should have it in a couple of days. eBay is my main source of electronic components these days as the usual sources like Farnell or Maplin all have hefty minimum order and postage charges that make ordering the single part you need to complete a project quite uneconomic.

Kits and Parts Universal RF Amplifier

 A few days earlier I received another kit from the USA: a QRP RF amplifier from Kits and Parts. I got this with the idea of using it with my Propeller beacon but it is probably too good for that. The beacon really needs only a simple class C amplifier to raise its output to a couple of hundred milliwatts. I had been tempted to go for a couple of watts but whilst WSPRing on 20m today and monitoring the signal on the K2 I noticed a weak in-band spurious around 14.05 MHz which no low-pass filter will eliminate. So it is probably best to stick to QRPp if using the Propeller as an RF source.

Another new arrival in the G4ILO shack was a GPS module from Hong Kong. This was used, ex-equipment, and cost about £12 including postage. I'm not sure what I am going to use it for but if I don't put it in the beacon to provide a time reference (and locator) for WSPR it would be interesting to try to make an APRS tracker using the Propeller chip.

So many projects! But I am convinced that having this amateur radio hobby to give me so many different and interesting activities is the reason I remain cheerful and positive unlike so many people who have the same health condition and seem to fall into a slough of despond and hopelessness. I may never complete them but at least they give me something to stop me dwelling on darker thoughts.

A cheap LCD

A packet arrived from China this morning containing a 16x2 LCD module which I purchased for the absurd sum of £1.93 including shipping. That wouldn't cover the postage from a UK supplier. I don't know how the Chinese do it and make a profit.

I bought the module with the intention of using it to make a user interface for my Parallax Propeller beacon. Having ordered it I was not sure how to interface the LCD to the Propeller so I chickened out and ordered an LCD UI module from Gadget Gangster. This is rather more expensive (though still a reasonable $29.99) but it includes a 4-way + depress button for menu navigation, plus a separate red button. It plugs straight into the Gadget Gangster board.  I reasoned that even with the hardware sorted the software would be enough of a challenge.

I have rather ambitious plans for this beacon. Perhaps over-ambitious. After reading Alex G7KSE's blog post about his Arduino based MSF 60kHz receiver I'm interested in interfacing one of the inexpensive MSF receiver modules to the Propeller. I could use this to display an accurate clock and also to control the start of WSPR beacons. As I'm a bit of an accurate time nut and have two radio controlled clocks in the shack (and a radio controlled watch) it is really no trouble to press a button to start the beacon at the beginning of an even minute and then keep time from there. But that isn't the point really, is it? What could be cooler than a shack clock that is also a WSPR beacon?

This microcontroller stuff is new to me and I have a lot to learn about it. One question I have is what do constructors who use Arduino boards or similar things like the Gadget Gangster do when they want to make a finished project? Do you just buy another development board to use for the next project, or are there simpler boards with just the microcontroller and its essential ancillary components which you use for the final version? I guess I'd still want the ability to update the software (firmware?) so there isn't much of the Propeller Platform board that I wouldn't be using.

Who broke it this time?

I have just finished the heavy dose of chemo for my fourth cycle so for the last week and for several more days it will be more than usually difficult to concentrate or even get motivated to do anything. Mostly over the last week I have just been tinkering with the Parallax Propeller WSPR and Opera beacon code and running the beacon barefoot on the air.

Stupidity seems to dog my programming efforts as much as my attempts at electronics construction. I wasted a couple of hours trying to understand why the Propeller was not doing what I wanted before eventually realizing that it was doing exactly what I had told it. I was nearly at the point of splashing out on ViewPort, an interactive debugger for Spin code that would allow me to step through my programs a line at a time. That would quickly have revealed the error, but it would have been a high price to pay to show me what was staring me in the face.

I had been pleasantly surprised at the reach of my barefoot 20mW Propeller beacon, receiving a number of reports of both Opera and WSPR signals. Today I modified my beacon program to transmit both a WSPR and then an Opera beacon, but frustratingly I have not received a single report of either of them on 30 metres. Have I broken the program again or did someone break the ionosphere? I really need to get motivated enough to build a small PA and boost the signal to at least the hundred milliwatt level.

Propeller takes to the air

Today I have been playing around with MEPT beacon code on my Gadget Gangster Parallax Propeller board. First I wandered over to Jeff, KO7M's blog and borrowed his WSPR beacon code.

Gadget Gangster in use as a 25mW WSPR/Opera beacon

WSPR was the thing I originally wanted to try when I decided to get the Gadget Gangster: I hadn't even heard of OPERA at that time. But I was unsure whether I would be able to generate the FSK frequencies WSPR uses: four tones separated by about 1.48Hz. Jeff decided to shoot as near as he could and programmed for a 2Hz separation of tones, and found that the signal was decoded by K1JT's WSPR program. So no problem!

I measured the RF output from the Propeller board and it was somewhere in the region of 25 to 40mW, depending on which measurement method you believe. I also looked at the output using my oscilloscope.

Output waveform from Parallax Propeller on 80m

It wasn't a pure sine wave, there's obviously some harmonic content there, but it was not as bad as I feared it might be. As I would be using my MFJ magnetic loop on 30m, which has a very narrow bandwidth, I decided not to bother with a low pass filter for the sake of these initial trials. I watched the seconds tick over on my shack radio-controlled clock, started the beacon and was soon rewarded by several WSPR spots!

WSPR spots for 25mW Propeller beacon

Because WSPR is a time-synchronous mode I had to start the beacon when the seconds ticked over to 00. This brought to light a problem Jeff had already observed: the Propeller drifts. The drift seems to be worst during the first few minutes of operation, so leaving the beacon running so it can reach a stable temperature would appear to be the solution. However that is not so easy when you have to power it on at an exact time. I will need to look in to implementing a real-time clock for WSPR, unless I want to interface a GPS receiver to the Propeller - which is certainly possible and something else I hope to try as I'd like to have a go at making an APRS tracker.

An advantage of the OPERA mode is that it is not time synchronous so I can leave the beacon running in that mode with an arbitrary delay between transmissions. My first OPERA transmission also produced several spots, including reports from fellow bloggers PC4T and G4NKX.

OPERA spots for 25mW Propeller beacon

I can also generate Morse and QRSS beacons using the Propeller chip. There is still a lot to do to reach my goal of a multimode, frequency-agile beacon, including adding a PA and some switchable bandpass filters. But so far this project has turned out to be easier than I thought it would.

Simple keyer complete

At last, I finally got the QRP keyer using KD1JV's Simple Keyer Chip boxed and working.

The completed keyer

As usual, nothing went according to plan. There must be some relative to Murphy's Law that states for any homebrew project the case will be just too small for comfort. A related rule is the one which guarantees that after you have drilled the case, the position of one of the switches or sockets will be in just the place where it fouls one of the components.

After my first attempt at getting it into the box the keyer was dead as a dodo. This turned out to be because I had forgotten to break one of the tracks on the Veroboard.

After the second attempt the keyer responded to the function button but there was no keying. That turned out to be because one of the connecting wires had broken at just the point where it was soldered. With my eyes as they currently are that took a while to spot.

When I had resoldered the connection and put the board into the case for a third time I noticed that another connecting wire was hanging on by one strand of copper. Lesson: don't use hookup wire from China, it is made from inferior grade copper.

View from the front

View from the back

This had taken me a day, so I decided to put the project aside until I felt calmer. The next day I re-made all the connections using new wire, put the board into the case one last time and it actually worked! But Murphy had one last laugh: Now I couldn't find the four screws for the Hammond case I was using. We searched everywhere. Fortunately my parts box had another Hammond case which sacrificed its screws for the benefit of the keyer. Later, Olga and I managed to find suitable replacements in the local DIY emporium so the other case won't be wasted.

This Simple Keyer is just what I need for the simple QRP rigs that only work with a straight key. The code speed is easily adjustable and there are two memories, one of which can be repeated as a beacon. I don't need more sophistication than that for QRP work.

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!