Multiple WSJT-X Instances on the Windows Desktop

With the recent 2.3.0-rc1 release of WSJT-X providing a first opportunity for everyone to try the new FST4 and FST4W modes designed for LF and MF, I have been getting questions about how I set up and manage multiple instances of the program. With these new modes it is very desirable to be able to run several instances of the program at a time, each with its own unique configuration and files area. This does not require installing the program multiple times. The program has a built in method to run multiple copies of itself from a single installation. The manual mentions starting multiple instances from the command line, but that is awkward when you need to start several instances for every operating session. Fortunately, desktop shortcuts can be used to start multiple instances of WSJT-X, and those shortcuts can also be pinned to the taskbar where they are always in view for starting instances even if the desktop is already completely covered over by various running programs. Here is a screen shot showing part of my desktop with five shortcuts, each of which starts a unique instance of WSJT-X:

Shortcuts for starting several instances of WSJT-X on my desktop

The shortcut named WSJT-X FST4W-120A starts an instance of the program specifically configured for the FST4W-120 submode. Likewise the others are for starting instances for FST4W-300, FST4W-900, FST4W-1800, and FST4. The latter is a more generic instance that I use for QSOs using FST4 mode. Each of the four FST4W instances has its own configuration, including a unique ‘My Call’ in the settings that adds a suffix to my call sign. That way, the spots I upload to WSPRnet identify which mode and T/R period the stations I decode are operating on. The FST4W-120 instance uses N1BUG/120. Likewise the others use N1BUG/300, N1BUG/900, and N1BUG/1800. I run all four of those every night that I am active, and usually have anywhere from one to three additional instances of WSJT-X running too.

So how did I create all those shortcuts? First I will describe the basic idea, then I will go into specifics of setting them up on Windows 10. The basics are:

  • Create a desktop shortcut to the WSJT-X executable
  • Rename the shortcut in a way that clearly indicates to you its intended use
  • In the shortcut properties, add a parameter to uniquely identify this instance to the operating system and the program

The latter is done by adding a parameter in the shortcut properties. This has the form of -r or –rig-name followed by a unique identifier of your choice. Here is what that looks like for the FST4W-120A shortcut:

The shortcut command for starting the FST4W-120A instance

Notice the –rig-name parameter followed by FST4W120A. I’ve got in the habit of using that instead of just -r which would be simpler. Please note that if you use –rig-name, that is two hyphens at the start. You need a space after .exe, then –rig-name, another space, and your chosen name for this instance. I know alphanumeric characters work for the name itself. I have not tried any non-alphanumeric characters. In this example, FST4W120A is the unique identifier that allows WSJT-X and Windows to differentiate this particular copy of the program from any other when it is started.

It is very important that every WSJT-X shortcut have its own unique –rig-name parameter! Do not try to run one instance without a –rig-name identifier along with one that does not. It won’t work!

After creating a shortcut for a new instance, don’t forget to start that instance and configure it. You need to add your call sign, locator, basic options, configure your sound card and rig, etc. All of these can be the same or different from other instances you may have.

Let’s look at how I create each shortcut. There are several ways to do it. Many people recommend making a copy of an existing desktop shortcut and reconfiguring the copy. That works but there are pitfalls if you make a minor mistake. I have gotten myself into a mess doing that a couple of times, so I no longer use that method. I will now describe in detail how I do it. A word of caution is in order here. Windows 10 can be configured in many ways which change the look and feel of this process. If you have Windows configured differently than I do, you may not see exactly what I see. I can’t discuss all of the various possibilities here.

First you want to open Windows File Explorer. You probably have a desktop shortcut or taskbar shortcut for that already. It’s the little yellow and blue folder icon. If you don’t have that shortcut, there are multiple ways to start File Explorer. A web search will turn up at least seven ways, but here is one way:

  • Click the Windows ‘Start’ button
  • Type ‘file’

You should see this:

You should see this after clicking the Start button (extreme lower left of this screen shot) and typing ‘file’

From there you can start File Explorer by clicking in the blue highlighted area at the upper left or just by pressing the Enter key on your keyboard.

Next you need to navigate to the folder where you installed WSJT-X. The default is C:\wsjtx but I have mine installed in C:\Radio\wsjtx.

  • You should see the name of your hard drive or SSD, usually C: on the left of File Explorer. A single click there should get you on your way, or
  • You may see your C: drive only on the right. It will probably take a double-click on that to get to C:
My File Explorer with my C: drive highlighted on the left

Once you’ve gotten to drive C: (or whatever drive you have WSJT-X installed on if you have more than one hard drive or SSD), you need to navigate to the folder where WSJT-X is installed using the list on the right. Here is what mine looks like after I’ve gotten to the proper folder:

One final step is to navigate into the bin folder. Now you should see a list of files. Here I have scrolled down that list to find the one called wsjtx.exe. Depending on how you have Windows configured you might not see the .exe part, but the name should be wsjtx and it should be identified as an Application:

Hover the mouse over that file to highlight it (as shown above) and press the right mouse button. You should see this pop-up menu:

Now move the mouse pointer over Send To > on that menu and click on Desktop (create shortcut) in the additional menu that pops up on the right:

Somewhere on your desktop a new shortcut should have just appeared. Mine looks like this:

I don’t like where it is, so the next thing I will do is left click on the new wsjt-x shortcut and drag it to some convenient spot on my desktop. Next, I will hover the mouse over it and click the right button. From the pop up menu I will choose Properties to get this:

I’m going to be making this one for starting an instance of WSJT-X which I will use for transmitting FST4W with my standard call sign, so that I don’t have to use one of my receive only instances with suffixes after my call sign. First I need to add a unique name to identify this instance to Windows. I’ll use FST4WTX. I carefully left click on the Target box, being careful not to delete any text that is already there. To the end of that I want to add a space character, then –rig-name, another space, and finally FST4TX. It must be typed exactly like that including required spaces. When I finish typing that I will click the Apply button and it will look like this:

Now on the tabs at the top I will click on General to get here:

Now I want to replace the shortcut’s default name, wsjtx.exe – Shortcut with something more user friendly that I can recognize as being my shortcut for starting an instance I will use for transmitting FST4W. I’ll choose something very similar to the parameter added in the last step, but making it a little more eye friendly, like WSJT-X FST4WTx. I will click into the box, delete the text that is there and type what I want. Now it looks like this:

All that remains now is to click the OK button. Now the new shortcut is ready for use on my desktop:

The first time I run the program from the new shortcut I will go trough all the settings in File > Settings, configuring it with my call sign, grid square and all other needed options. Once I have it all set the way I want it, I will use this particular instance only for transmitting FST4W. Since I have receive instances which I want to upload to WSPRnet with the unique call sign suffixes indicating submode, I will remove the check from ‘Upload spots’ on this one’s main window.

These same steps can be used to create as many different shortcuts as you need for starting different instances of WSJT-X. Just remember to give each of them a unique –rig-name parameter in the shortcut properties, and finally name it something convenient.

If you often have a lot of windows open, covering the desktop you may find it helpful to pin desktop shortcuts to the taskbar. Just right click on a desktop shortcut and choose pin to taskbar from the popup menu.

2200m Reboot: Phasing Exciter

External view of the phasing exciter

In early 2020 I began phasing out much of the first generation LF equipment and building replacements. My LF operating interests focus largely on DX. As I have learned more about all of this, it became obvious I needed some upgrades. This is the second in a series of posts about new equipment for our lowest frequency amateur radio allocation.

Like the first generation receiver, the transmitting downconverter did not have adequate frequency stability for slow modes on LF. I also wanted something that didn’t tie up my only HF rig when operating on 2200 meters. After reviewing several designs for phasing exciters I settled on a design by W1VD. I built mine Manhattan style using MEPads and MESquares from QRPme.

The MPS6650 and MPS6652 transistors used by W1VD are no longer available. I successfully substituted BC33716BU and BC32716BU devices but I have not been able to achieve the stated +20 dBm output. Mine will only make +16 dBm before the output waveform becomes distorted. This works OK with my amplifier but is a subject I would like to revisit at a later date.

Initially I encountered some difficulty getting good carrier and opposite sideband suppression. I traced the problem to the LO signal to the two mixers not being 90 degrees out of phase. I built several variants of the quadrature hybrid but I could not get accurate 90 degree phase shift or equal amplitude. Trying some alternate approaches, I achieved success using a Wilkinson divider and phase shift network. Some cut and try adjustment of two capacitor values was needed but in the end I achieved accurate 90 degree phase shift with similar amplitude on both ports. I used 6 dB resistive attenuators on the two LO signals before feeding the mixers. The two outputs from this circuit go directly to pin 8 on the two SBL-3 mixers in the exciter. The 6 dB pad, C1, C2, T1, C3, C4 and the associated 49.9 ohm resistor shown in the W1VD exciter schematic were omitted. With this arrangement I was able to achieve better than 55 dB carrier and opposite sideband rejection after careful adjustment of the level and phase balance trimmers in the exciter. If you build this and find it is operating on the wrong sideband, reverse the LO inputs to the mixers. If you look closely at the blue and orange wires coming off the LO divider and phase shift board, you will see they cross over each other on the way to the mixers on the main board below. Mine had ended up being on lower sideband the first time around! One other change should be made to the phasing exciter if you will be operating it into a 50 ohm load: omit the 49.9 ohm resistor in series with the output. The 1 uF capacitor should connect directly to the junction of the two 5.1 ohm resistors.

LO filter and Wilkinson divider with phase shift network

I am using the same Leo Bodnar GPS Clock that supplies 408000 Hz to the new receiver. It supplies 136000 Hz square wave to the exciter, which I low pass filter before the divider.

Internal view of the completed phasing exciter. Originally mounted to the side of a rack in my main shack, I had placed the power switch and LED on the side opposite the connectors. When I subsequently relocated LF operations to the workshop, that was not convenient so I added another switch and LED near the DC power connector.

I have many hours of operation with this exciter in various modes. It has performed well. One thing this exciter does not like is magnetic fields which can couple 60 Hz energy to the audio circuits. Don’t put it too close to a linear power supply!

2200m Reboot: The Receiver

The SSR-2200E, my second generation LF receiver based on the SoftRock Lite II

In early 2020 I began phasing out much of the first generation LF equipment and building replacements. My LF operating interests focus largely on DX. As I have learned more about all of this, it became obvious I needed some upgrades. This is the first in a series of posts about new equipment for our lowest frequency amateur radio allocation.

After using the original modified SoftRock Lite II receiver for three years, it was time to move on. That first receiver served me very well. With it I was able to make three trans-Atlantic QSOs, and heard a lot of DX on various modes. In the end, however, I wasn’t satisfied with the frequency stability of the crystal oscillator, which was about 1 ppm, or a little less than 0.15 Hz drift on 2200 meters. That may seem completely insignificant to the HF, VHF or microwave operator but for the most serious DX pursuits on LF it not sufficient. With the one watt EIRP legal power limit, propagation and high noise levels at 137 kHz we need very slow modes to succeed over great distances. As a general concept, the slower the mode the greater the frequency stability needed. Legacy modes include QRSS (extremely slow CW meant to be read visually from a waterfall) and its derivatives like DFCW. Readers may recall my first DX QSO with 2E0ILY used DFCW60, meaning that each “dit” or “dah” takes 60 seconds to send! Drift of 0.15 Hz is clearly visible at that speed and can lead to difficulty “reading” signals at even slower speeds. Today we have various slow digital modes for beaconing and QSOs. At the extreme, EbNaut requires transmitter and receiver drift be no more than a few tens of microHertz! Others are more tolerant but current evolution suggests one should strive to stay within 0.01 Hz or better during any 30 minute period if DX is of prime interest.

During those first three years I had tried various receiver, filter and preamp configurations. I now know what is needed with the SoftRock and my available antennas. I wanted to combine the filter, preamp and receiver into one box but I wanted to use a GPS referenced local oscillator for stability. In the end I settled on a design which puts all but the local oscillator into one box. The LO is a separate Leo Bodnar GPS Clock which supplies 408 kHz for the receiver (divided by four in the SoftRock quadrature LO generator) and 136 kHz for a 2200m phasing exciter.

The major building block for the receiver is a SoftRock Lite II kit from Five Dash. A few modifications need to be made for 2200m operation. The schematic shows the values for parts that need to change for operation on this band (C3, C4, C10, C11, C12, L1, T1, R5, R6, R16), as well as the removal of the crystal and external LO connections in its former place. The capacitors can be ceramic. I recommend mounting the SoftRock Lite II board with the insulating hardware that comes with it. Ideally one wants everything isolated from the metal box except for the shield of the audio cable connector. To maintain that one ground point I run the receiver either on a battery or an isolated wall wart.

Schematic of the modified SoftRock Lite II

For the front end stages I have married a filter design by YU1LM and a preamp design by W1VD. The filter provides a bandpass response to keep out of band signals from overwhelming the receiver, while the preamp provides about 20 dB gain which is needed with many small receiving antennas on LF. You want enough gain in the front end and receiver so that the noise floor comes up at least 10 dB when you connect the antenna. If this seems a little different from conventional advice, consider that we are dealing with extremely weak signals where even fractions of a dB can make a difference. If we want to keep the signal to noise ratio from being degraded a meaningful amount, we need that much gain to be sure the SoftRock and sound card noise floor don’t degrade S/N of the system. With the exception of the 10 uF electrolytic, all capacitors are ceramic types.

Schematic of the front end filter and preamp

Next I needed a suitably stable local oscillator. We need a final LO frequency that is close enough to the 2200 meter band to allow tuning it with whatever sound card will be used. If the sound card sample rate is 96 kHz, we need to be within 48 kHz of the receiving frequency. I recommend staying a few kHz less than that due to the way anti-aliasing filters in sound cards work. This means we want our LO to be between about 96 kHz and 178 kHz in practice, preferably avoiding putting it “in band”. The LO frequency is divided by four in the SoftRock quadrature generator circuit. This means we need to inject a frequency four times higher into the receiver. Anything between 384 and 712 kHz will work. I was already using one of the two outputs from the GPS Clock to provide 136000 Hz LO to my phasing exciter. Available frequencies for the second output are somewhat limited and tied to the first frequency but in this case 408000 Hz is one of the options, and it is perfect. That puts our final LO at 102 kHz, comfortably within range, yet far enough removed from the band of interest to put the image frequency around 67 kHz, well down the slope of the receiver front end bandpass filter. Perfect!

First I tried injecting the 408 kHz square wave directly into the SoftRock. It worked but I didn’t have a good feeling about it. For one thing, that meant that the SoftRock and GPS clock grounds were connected, a situation which I was trying to avoid in case of ground loops and noise getting into the system. The GPS Clock also didn’t like the impedance, causing it to put out not only the harmonic rich square wave but also a significant amount of HF energy as ringing due to impedance mismatch. I tried using a transformer (for ground isolation) and low pass filter to clean up harmonics but this made the GPS Clock even less happy with a lot of ringing due to reflections. Since I had signal to spare I solved this, albeit somewhat crudely, but inserting a 10 dB attenuator between the GPS Clock and transformer. This gave a nice clean sine wave at sufficient level into the SoftRock LO circuit. I don’t claim this design to be elegant or perfect, but I do claim it works well for me. I used film capacitors in the filter because I had them on hand, but ceramic should be quite acceptable.

Schematic for the LO isolation and filter circuit

This new receiver has been in operation for several months. Sensitivity and gain is more than adequate for use with my LNV antenna. Frequency stability is now determined almost entirely by sound card sample rate drift and is on the order of 0.01 Hz over several hours. This is sufficient for all but EbNaut, where the sound card sample rate requires continuous monitoring and correction. I have not conquered that yet.

Internal view of competed receiver

Building a Filter

Occasionally I get asked how I go about building circuits on proto boards. This post describes how I built a low frequency band pass filter.

For some circuits, the layout will not be so easy, but for simple filters like this I have a method I almost always follow. Let’s start by looking at the schematic for the filter I will be building.

Original schematic diagram for the filter

Now let’s think about that for a moment. We see one side of four capacitors (C2, C3, C5, C6) is connected to circuit ground. Also the shell of the input and output coaxial connectors are connected to circuit ground. If all of those points are connected to ground, then they are all connected to each other. To make this clearer, we can redraw the schematic as follows.

Schematic redrawn to make it clearer how all “ground” points are connected to each other

I like to lay out my parts on the board so they physically resemble the schematic representation. If you think of the top of the schematic as north, bottom south, left west, right east as if it were a map (it is a circuit map!), then we can think in terms of components oriented along a north-south line or east-west line. C1, for example, has one of its leads on the west and another east. C2 is a north-south oriented part. For a filter such as this, I start by laying out all the capacitors on the proto board in much the same way they are represented in the schematic, making sure to leave spaces to fit in the inductors later on. As I put each capacitor onto the board, I spread its leads slightly on the back side so the parts won’t fall off the board when I turn it over for soldering. They don’t have to be spread much.

Proto board with capacitors laid out according to the schematic representation, leaving gaps for the inductors

I then flip the board over and just solder each capacitor lead to the pad around it. If using a temperature controlled iron, I suggest about 650F for soldering on these boards. Then I clip off excess lead length. Next, with the the help of the schematic I identify any capacitors that are connected to their neighboring capacitor and make those solder connections on my board. I’ve developed a method of doing this using a solder blob but many builders will prefer to use a short piece of wire soldered across the pads as a jumper. Another method is to fully bend over one or more leads before soldering to the board, so that the component lead itself becomes the jumper. That method is easy, but if it becomes necessary to remove a part later, it can complicate matters. Finally at this stage I connect all the grounds together in a row, just as they are shown in the modified schematic. Again, using solder blobs I have developed a technique to build such circuit paths entirely of solder but a buss wire soldered along the board will probably be easier for most builders. With regard to my solder blobs and building solder rows, it is much easier if the iron is not too hot. 650F is on the warm side. 600 or even a little lower can make it easier to bridge blobs without them separating from neighboring blobs while doing it. This is second nature to me now, but it took a while to develop this skill. It involves getting a decent size blob of molten solder on the tip and then placing it into the gap where you want to form a bridge. Putting the iron in there and then trying to add the solder does not work!

The back side of the board after soldering capacitors and forming the ground path along the bottom edge

The next step is installing the inductors. In this case, they are toroids. It may appear that the toroid itself is oriented along a north-south line while the schematic shows them east-west, but if you think of how the two leads come off the sides of the toroid, the leads are oriented east-west as are the connection points on the schematic. I hate having my toroids end up loose and wobbly on the board, and spreading leads doesn’t keep them tight against the board while soldering when small gauge wire is used. I have developed a method to help hold those little devils in place and keep them snug against the board while I solder them. It involves clip leads on the end of strings which loop up and over an overhead support with weights on the other end. This puts upward tension on the leads, pulling the toroid snug against the board.

Clips of toroid support and tension system clipped to inductor leads
Wide shot of the toroid support and tension system. I didn’t bother tidying up the bench before taking these photos!

A few words about soldering of the enameled wire may be in order. Life is too short for scraping or sanding the enamel off these very fine wires. I use wire with enamel that can be heat stripped. The heat of a hot soldering iron (I recommend 750F) along with fresh solder and perhaps a bit of liquid flux on the wire (if it is available) will burn the enamel off. The problem is it takes a few seconds and that much heat can cause the copper rings to come off the proto board! I hold the soldering tip against the wire about 1/16 inch above the board, being careful not t let it touch the board. It is necessary to apply a bit of solder to get the heat transfer working well enough but with a bit of practice the insulation can be burned off and the wire tinned without much difficulty. Dabbing a bit of flux (liquid or paste) on the wire before applying heat can be very helpful. If the wire is fluxed, usually just getting a small blob of solder on the hot tip and touching it to the wire for a couple of seconds will get the job done. I admit my first few attempts at this didn’t go so well but I got the hang of it after a bit of practice. Once the lead is properly tinned I can solder it to the pad on the board. At 750F this should be done quickly! Sometimes I lower the heat to 650F before soldering to the board. Once both leads are soldered to the board, I connect them to the adjacent components using my solder blob technique while the overhead support system is still keeping tension on the wires. Once all the soldering around these leads is finished, the alligator clips can be removed and the inductor leads cut short.

In this simple filter build that’s it except for connecting it to the outside world in whatever manner is appropriate for the project at hand.

Top view of completed filter
Bottom view of completed filter

Personal Perspectives on the Bruce Kelley Memorial QSO Party

It’s that time of year again – time for the annual Bruce Kelley 1929 QSO Party. This unique event, sponsored by the Antique Wireless Association, is like an “activity period” for use of transmitters built around circuits published in or before the year 1929. Many say it is meant to be a fun event, not a contest.

I have a 1929 TNT transmitter I built in 2011 after long time friend Ron, N4GJV mentioned the Bruce Kelley party to me. I had always been fascinated by the unique appearance of 1920s transmitters. Learning of this annual operating event compelled me to build one. Every year at this time, I struggle trying to decide whether to participate or not. I took part in 2013 and 2015 under my own call sign, taking first place both times. In 2016 I was given the special honor of operating under club call sign W2ICE, which was Bruce Kelley’s call sign. I haven’t participated since then. The Bruce Kelley is one of those events I want to love, but in reality my relationship with it is more of a love-hate thing. To understand why, I have to acknowledge that I could be a poster child for adults on the autism spectrum. I am very seriously impacted in several ways, the effects of which are evident in every aspect of life.

They call it a party, but what it is depends on who you talk to. For some it is a very informal event, a time to fire up the really old rigs and make a few contacts for fun. For others it is a contest and they are out to win. Clearly I fall into the latter category. It’s like the old Pringles commercials – bet you can’t eat just one. Nope, I eat the whole darn can of ’em! I find it impossible to just have fun and not make it about competing. Competing is the fun. Well, that and the warm glow of a UX-210 filament filling the shack. I suppose by nature I am a very competitive person. This is stifled everywhere else in life, so it comes out in ham radio. Ham radio is that one special area in which I feel confident and comfortable, whereas everything else seems alien. This is autism clearly showing itself. It would also be fair to say that many on-air aspects of ham radio have not been inviting or have been downright uncomfortable because of my life challenges. Conversational QSOs and ragchewing are pretty much out. Contesting, being a facet of the hobby that is generally quite comfortable, has gotten into my blood and I always feel it pulling at me. Whatever you call it, results of the Bruce Kelley event are published, and a plaque is presented to the station making the most contacts. To me, that makes it pretty cut and dried – whatever the name, it’s a contest. I have tried to operate casually, but competitive instinct takes over, pushing good sense aside.

On the face of it, you’d think that wouldn’t be a problem. I am a contester and to me the Bruce Kelley event is a contest. So what’s the deal here? Well, for for one thing the exchange is very long: signal report, name, state, transmitter type and year, power level. That is much longer than most contest exchanges and gets into my discomfort zone. This is compounded by it being a low power event. I might be ousted from the ranks of “1929” builders and operators for admitting this, but I am not normally a QRP operator. I stress about whether I’m going to be copied when running low power. While sending the long Bruce Kelley exchange, I tense up and break out in a sweat. With low power and the long exchange, there is a very real possibility that it won’t be copied entirely and repeats will be needed; additionally there is always the risk of “losing” a QSO that can’t be competed because conditions changed, something I just have a hard time with. Overall, operating in this contest is difficult and exhausting to me. Yet once I start, the contester in me takes over and I am there for the duration. I would be much more comfortable if the exchange were short, say signal report and state. But that would ruin the event for the majority of participants. My perception is that many “29” operators are folks who enjoy a good ragchew. There is nothing wrong wit that. I admire them and wish it were that way for me. Furthermore, most who participate in this event want to know the other operator’s name and what transmitter they are using. To most, that is part of the fun. To me, it is torture. I too am very interested in knowing what the other guy is using for a rig and so on, but getting that information over the air while operating QRP is not a comfortable thing.

There are good reasons why this is a low power event. For one, it is far more difficult, dangerous and costly to build a high power transmitter conforming to 1929 design. If high power were allowed, low power stations would have no chance to be competitive, and many would be priced out of the game. Even if low power is stressful for me, I wouldn’t want that to change for this event. One of the things that make it special is that the playing field is maintained such that those on a modest budget can compete. I like that. There is another good reason for keeping this a low power event. The old rigs don’t sound like modern ones. They have chirp, clicks, buzz and so on. This increases the risk of interfering with other users of the bands. Low power helps mitigate that risk. Overall, while I am attracted to this unique operating event, I must acknowledge is wasn’t crafted with the likes of me in mind. Which is fine, of course.

Another factor which has made this event less enjoyable for me has been use of a straight key. Back when I participated, this was not not mandated by the event rules, but many participants feel using anything else is not in the spirit of the event. Now the rules clearly state hand keys or Vibroplex type keys should be used. Personally I love the smell of ozone as the high keying voltage and current sparks at the key contacts! Ah, “real” radio! Using a straight key is consistent with the spirit and reality of 1929. But I have some issues with my arm, compounded by surgery on it a few years ago. Even just pounding out one or two QSOs on the straight key makes my arm ache. After my last participation in the Bruce Kelley party, my arm hurt for weeks. I even consulted a doctor to see if I had done any lasting damage. I decided I would not be doing it that way again, and built a keyer which can handle the high keying voltage and current of these vintage rigs. When I mentioned this in one of the forums, there was something of a small storm of controversy regarding use of anything other than a straight key. This has been a discouraging factor to me since that time.

So, here we are at that time of year. The Bruce Kelley 1929 QSO Party kicks off in just over 48 hours. The TNT is set up and tested. It is connected to the new keyer. But I have yet to decide whether I will operate or move the TNT back into its usual home, under an acrylic cover in my living room. It does make an interesting display piece and I enjoy seeing it every day, but it would be nice to use it on the air a bit more. Edit: Just over 12 hours to go and the deciding factor is the rule on using hand keys. I’m out. The rig goes back to its point of display as an ornament.

2200m Variometer Failure

On the morning of January 15 I was nearing the end of a 72 hour test of the JT9 submodes (JT9-10, JT9-5, JT9-2, JT9-1) on 136.395 kHz. The transmitter had been running 87% duty cycle for two days and as far as I knew all had been well. On this morning I checked in on things when I got up just before sunrise. It was running as expected with the waveforms on the ScopeMatch looking normal. I went about some morning chores and came back about 20 minutes later to check again. The transmitter was still running but the antenna was far off resonance. Minor changes are common but this was more than a minor change. I knew something was very wrong.

Loading coil and variometer assembly. The outer coil is 2 mH. The inner coil is about 180 uH and is driven up and down by a motor and threaded nylon rod. The adjustment range is approximately 2.3 to 2.5 mH total. This is more than sufficient to resonate the antenna anywhere in the 2200 meter band and allow for changes in weather conditions.

I quickly shut down the transmitter, grabbed my binoculars and went to the window to inspect the antenna. All wires were up and intact. I then hastily bundled up and went outside to check the loading coil / variometer. It didn’t take long to realize where the trouble was. When I removed the cover from the assembly housing, acrid smoke came billowing out and I could feel heat radiating from somewhere inside. This was not good! Since the smoke was so thick and presumably toxic, I could not do a full inspection until things had aired out a while.

2200m (left) and 630m (right) variometer enclosures. The blue drum is not tall enough to fully enclose the 2200m unit, hence the upside down bucket which is part of the lid assembly.

Upon subsequent inspection I found the bottom of the moving inner coil badly damaged. I can only guess as to what happened. Careful inspection of the following pictures will reveal something of the construction. There was a wire (12 AWG solid, insulated) running down the length of the form on the inside. This provides connection from the bottom of the inner coil to a a terminal at the top of the coil form which is jumpered to the top of the large outer coil. At both ends, the method of feeding through the form was a 18-8 stainless machine screw with washers and nuts as needed. On the inside the ring lug on the wire was between the head of the machine screw and the coil form. Stainless hardware may not have been an optimal choice. It stays clean practically forever but it has poor electrical properties. I had assumed it would be fine with the expected 2 amps or so of low frequency RF current.

What I suspect happened is that over time, probably aided by thermal expansion and contraction cycles of the PVC form, the hardware became loose on that bottom connection. As it began to loosen slightly, resistance of the connections may have increased somewhat, leading to more heat being generated. This may in turn have led to some slight softening of the PVC, allowing pressure on the connections to relax even more. I believe eventually it became so loose there was arcing which produced extreme heat in a localized area, eventually leading to the damage.

Before disassembly, some damage can be seen at the lower end of the inner coil.
After removing the inner coil assembly, the extent of damage is more apparent.
With the coil removed from the base plate there is more evidence the machine screw was the source of the problem. All of the damage centers around it. The wire inside is badly heat damaged, and the PVC form has either been on fire or has suffered damage from arcing (or both).

In hindsight, there may have been two warning signs that something was not right. If these were signs of failure in progress, things had been going south for some time. About two or three weeks prior to this incident I had noticed that when I was transmitting I would sometimes see “fuzz” appearing on both sides of my signal when viewed on the waterfall of my SDR receiver. It usually lasted only for several seconds, then cleared up. I did wonder about arcing, but the ScopeMatch looked perfectly normal. I put it down to just another artifact of severe receiver overload. It’s not as though my signal ever looked clean in the local receiver! There was always plenty of junk, no doubt worsened by the use of back to back diodes across the receiver front end to prevent damage from my own transmissions. But this particular “fuzz” phenomenon was something I hadn’t recalled seeing previously.

The second possible warning sign came 24 hours prior to discovery of the failure. On that morning resonance suddenly “jumped” higher in frequency. It wasn’t a big change, but was something I hadn’t seen before in benign weather conditions. Re-resonating took care of it but about an hour later it “jumped” back to the original resonance condition and needed to be adjusted again. This unexplained behavior should have been a warning that something was not right.

Much of what I think I know about this failure is speculation based on inspection after the fact. My theory seems further supported by the fact that the other stainless machine screws passing through this form had all loosened considerably. I know they were tight when it was built, but I was able to remove them using just my fingers. I will never know for sure exactly what happened, but the new inner coil will be designed to avoid the suspected failure scenario. If it fails again, I will have to reexamine my theories!

Mowable Temporary Cables

What? Mowable cables? That doesn’t make any sense! Let me explain. Throughout my nearly four decades exploring radio, I have often had occasion to run a “temporary” cable to some antenna. Usually these end up laying on the ground where they quickly become a nuisance, having to be moved every time the grass needs to be cut. This often continues for some time. After all, in a ham radio sense the definition of temporary is “anything expected to be in service for less than the life expectancy of the operator”. About year ago I had a sudden explosion of “temporary” cables. I needed to run coax and a variometer control cable to my new 2200 and 630 meter transmitting antenna, as well as coax to a receiving antenna for those bands in another location. These were put down just after the last lawn mowing of the season, but were at risk of damage from the snowblower as I kept a path cleared to the transmitting antenna during the winter. This summer they have been a constant source of irritation as I had to move them every time I mowed the grass.

Since I still can’t afford good coax and conduit to do this job in a permanent (meaning less irritating) fashion, something had to be done. One obvious solution is to dig a shallow trench and lay the cable in it — with our without burying afterward. This tends to be a lot of work and it’s messy, disturbing the grass (uh, I mean the weeds) and leaving dirt strewn all over. I was looking for a cleaner and, hopefully, easier method. One morning about 2 AM it came to me. I sat bolt upright in bed, sending Boo (the cat, who had been asleep on my chest) fleeing for cover. Who said you had to dig a trench? I have soft, sandy soil. Surely one could press a trench into the ground without the mess. It just might be easier, too. The following series of pictures depict the process, which worked very well.

Step One: Mark a line. Drive in stakes at each end and at any locations along the run where a bend is required. Run string (or small wire) from end to end, then spray paint a line on the ground along it.

Details of the string (wire) and painted line at a bend point.

Step Two: Hammer a slot into the ground. I used an 8″ x 8″ dirt tamper and a 10″ length of 1.6″ OD steel pipe. Lay the pipe on the painted line and hammer it in until its top is flush with the surface of the soil. In my soil this takes two to three blows, and the flat plate of the tamper makes it easy to know when you’ve reached the correct depth. This photo shows the pipe in place before being driven into the soil.

Here is a photo showing results after the pipe has been driven flush with the soil. To continue I simply pull out the pipe and move it forward 9 inches (just a bit less than the length of the pipe), then drive it into the soil again. The process moves along quite quickly.

Step Three: Lay the cable into the trench. I make 15 to 20 feet of trench at a time, then lay cable into it, then do another section of trench.

The completed job. There is no messy strewing of dirt, the paint line has virtually vanished, and the cable can barely be seen if one is not standing very close to it or directly in line with it. The top o of the cable is 3/4″ to 1″ below grade, so it is out of danger from the mower. Of course it is still subject to damage from any number of things, but with temporary cable runs that is usually a fact of life.

First USA to Europe Amateur Radio 2200 Meter QSO

It was early morning on the 28th day of March, 2018. Most people were sound asleep but not me. I was in my ham shack, hands trembling, heart pounding as I typed a few letters and numbers into my logging program. I could barely breathe. I had just completed one of the most exciting QSOs of my nearly four decades chasing DX. This single QSO cost more money and time than any other I had ever made. It was a QSO with England. You may wonder what is so exciting about that when any ham with five watts and a piece of wire can contact England from Maine. Well, this was special because we did it on the 2200 meter band. It was the first amateur radio USA to Europe QSO on what is, for us, a new band. This was no easy feat. It required months of station building and four nights just to complete the QSO. Some would call it a ridiculous folly and see no sense at all in it. But to me this is the true spirit of amateur radio, finding a way to communicate against the odds, adapting equipment and technique to accomplish the desired result. It is man and his machine against nature, determined to succeed under the most difficult circumstances.

The 2200 meter band allocation is 135.7 to 137.8 kilohertz in the long wave part of the radio spectrum known as LF or low frequency. In some ways this goes back to amateur radio’s early roots on 1750 meters, but it had been more than 100 years since U.S. amateurs were allowed to transmit in this part of the radio spectrum. These frequencies are not easy! Normal size antennas would be huge. A half wave dipole would be 3400 feet long; a quarter wave vertical towering to a height of 1700 feet. Natural and man made noise tend to be very high in this part of the radio spectrum and ionospheric propagation is feeble compared to the short waves. On top of that, we are only permitted to run one watt effective isotropic radiated power (EIRP). That is flea power compared to what we can use on most any of our higher frequency allocations! By comparison, when I was doing EME (moonbounce) on the two meter band I was legally running about 450,000 watts EIRP. But ham radio DXers who like a good challenge can be a very determined lot. The greater the challenge, the greater the reward.

I became interested in 2200 meters in late 2016 after the local club asked me to prepare a report on this and the 630 meter band, which were expected to soon be opened for amateur radio use in the U.S. At that time the only way to legally transmit on either band was to get a Part 5 FCC license under the experimental radio service. One could almost write one’s own ticket on power limits and frequency allocations but this wasn’t amateur radio. I did apply for and was granted a Part 5 license but never used it since FCC opened these new bands to amateurs just as I was getting a station put together. I found receiving on 630 meters to be relatively easy, if somewhat plagued by noise and available antennas. But 2200 meters was a very different thing. It took weeks of experimentation and testing to detect the first trace of signal on this band. Many weeks later after more trial and error I was rewarded with my first reception of a ham radio signal from Europe on the band when DC0DX appeared in my WSPR decodes. I confess it was then that I first started to dream of someday making a two way QSO across the Atlantic on long wave.

I thought I had plenty of time to build a station, since the FCC process on opening these bands had been dragging on for years. But in the Spring of 2017 the announcement came that we would get these new bands in a few months! Now the race was on. I frantically began building transmitting apparatus. I didn’t quite make it for opening day in October but I was on the band a few weeks later. Early amplifiers were plagued by budget shortfalls and poor performance. By mid February, 2018 I had managed to achieve 0.5 watt EIRP, just three decibels below the legal limit. The flood gates opened and to my amazement I started receiving numerous WSPR decodes from European stations. Wow!

I believed a two way trans-Atlantic QSO was in my future but was not sure when. I was eager for an attempt but still very much struggling with equipment and budget. I was hearing stations from Europe. Stations from Europe were hearing me. But for the most part, those who heard me did not have transmitting capability or not sufficient to reach across the Atlantic. The best bet would seem to be 2E0ILY. We had conducted tests earlier in the season and I could often copy his JT9 beacon. Chris could occasionally copy my WSPR signal but not at sufficient strength for JT9 to be viable. I knew there were ways to get it done, but this would take several nights. I was hesitant to ask anyone to commit such effort and time to a QSO.

As the relatively quiet season was drawing to an end I realized another season is never guaranteed for any number of reasons. I had given the matter considerable thought. There were no practical digital modes which would work with the low signal levels involved. Two old school modes came to mind: QRSS and DFCW. Both are very slow, trading time for weak signal detection capability. QRSS is extremely slow CW, so slow in fact that it can only be copied by reading it off a computer screen. In this case, a speed of QRSS60 would be best, meaning that each dot would be 60 seconds in duration. A dash is three times as long, just as in normal CW. This mode requires nothing special for equipment, as it uses on/off keying of a carrier and is fairly tolerant of frequency drift. But, the shortest element, the dot, sets the achievable signal to noise ratio. There is no advantage gained from the dashes being three times as long, so it is essentially time wasted. Time is valuable, as signal fading means you have a limited amount of time to copy the message. DFCW, or dual frequency CW is an offshoot of QRSS in which dots and dashes are the same length but sent on slightly different frequencies so that one may be differentiated from the other. This saves considerable time with no reduction in signal to noise ratio but requires more complex transmitter keying and reasonably tight frequency stability. In a typical DFCW60 transmission, the dot to dash frequency shift is a small fraction of a hertz. Transmitter and receiver drift must be held to less than this in order to avoid dot-dash ambiguity at the receiving end. It would take about an hour to send two call signs at DFCW60 speed. It was now late March. Clearly there would not be enough common darkness between Maine and any part of Europe to allow a QSO to be completed in a single night at this speed.

It may be useful to consider what is a QSO. These days the term means different things to different people. I came up through the DXing ranks with what is now a somewhat old school definition for a minimum acceptable information exchange to claim a QSO under very weak signal conditions. I still firmly believe in the old way, as we are after all supposed to be communicators. That definition is that each station must receive from the other both call signs, signal report or other piece of information, and acknowledgment. This requires that two transmissions be copied in each direction. Anything less than that does not seem like communication to me, and leaves me with no sense of accomplishment.

It seemed the best way to go about it would be to borrow operating and reporting techniques from EME, modifying procedure slightly to account for the much longer period of time required to send a message on the long waves. In this procedure, the letter O would be used as a signal report to indicate full call signs had been copied; R and O would be used to indicate full call signs plus signal report had been copied; R by itself to indicate call signs, report, and R (as part of R and O) had been copied. As for timing, it seemed sensible to use night by night sequencing. That meant the two stations would take turns transmitting, one going the first night the other the second, alternating back and forth throughout the QSO. It would take a minimum of four nights to complete a QSO, assuming the full message could be copied each night. If it wasn’t, additional nights would be required for repeats. That’s really slow! But it did offer some advantages with the equipment available. In order to achieve the required frequency stability I would have to use my QRP Labs Ultimate 3S beacon transmitter. The U3S is a great piece of gear, but editing messages is tedious. Night by night sequencing would give me all day to change the message for the next night’s transmission! A complete QSO would look like this, where bold indicates my transmissions, italics indicate transmissions from the other station:


Meaning of the first line is obvious. I am transmitting both call signs. In the second line my QSO partner adds the signal report, O, to let me know he had copied both call signs fully. In the third line I send RO which means I have copied call signs and my report, your report is O. In the last line my QSO partner sends R, meaning I have copied all on my end. When I copy the R the QSO is complete. If a message is not copied, or not enough information is copied, then one continues to transmit the previous message until getting something back which advances the QSO.

I had worked out a viable technique. Now I just needed a QSO partner. Just in time I worked up the courage to ask Chris, 2E0ILY if he would be willing to give it a try. I was very happy when he said he’d have a go at it.

We had decided I would transmit the first night, so I set the U3S to send ‘2E0ILY N1BUG’ over and over during the hours of common darkness between our respective locations. It turned out to be an ugly night in terms of weather. I was getting heavy wet snow squalls. Nothing causes a 2200 meter Marconi antenna (vertical) to go out of resonance any quicker than wet snow! These antennas are electrically short and require huge loading coils to resonate them. They are high impedance antennas and the bandwidth is very narrow. These antennas are prone to changing characteristics on a whim. Every time the snow started, stopped, changed intensity or the amount of snow clinging to the antenna changed, the thing went wandering up or down the band and required retuning for resonance on the operating frequency. Fortunately the variometer at the antenna base was motorized and I could adjust it from the comfort of my transmitter room. But I had to keep a constant vigil, watching antenna resonance and adjusting as needed. I had my finger on the switch for variometer adjustment far more than not. After a while my fingers were getting sore from constantly manipulating the tuning switch. Perhaps I shouldn’t have used a miniature toggle switch there. If you think this was an automated QSO without operator involvement, think again! My presence and diligence at the controls was absolutely vital that night!

Message copied from 2E0ILY on the second night of the QSO (annotated). Note dots on the lower frequency, dashes shifted 0.187 Hz higher. When the signal is this strong, elements tend to bleed together a little but since they are of fixed length it is still very readable.

The next night it was my turn to listen. Due to the extremely slow speed DFCW is copied visually¬† using software designed for this purpose. Anxiously I stared at the screen. When I wasn’t nervously pacing, that is! I began to see traces of signal, then an odd letter here and there. There was a B, a 2, a Y and I even thought I saw an O but couldn’t be sure. Eventually conditions stabilized and I began to get steady print on the screen. Waiting 60 seconds for a dot or dash to fully paint on the screen can be agonizing. Slowly the elements accumulate and become characters. If you are lucky, propagation holds up long enough to copy the full message. Fortunately, after somewhat of a slow start copy remained solid and I eventually had N1BUG, 2E0ILY and a very nice O painted on my screen! I had copied full call signs and a signal report indicating Chris had got full call signs from me the previous night! We were half way there!

The third night I was transmitting again. Since I knew Chris had already copied full call signs from me, it was not necessary to transmit them at this stage of the QSO. Technically I could have just sent RO repeating throughout the night, but being of the cautious type I decided to include call sign suffixes to provide positive evidence the correct station was being copied. Thus the message I transmitted was ‘ILY BUG RO’. This was a risk as it takes far longer to send than simply ‘RO’ and signal fading can be a huge factor. At least the weather was better and I didn’t have to ride the variometer all night.

Soon it was night four, back to pacing and staring hopefully at the screen. I was especially nervous that night, as I had some strong, drifting interference right on top of Chris! Finally it moved just enough that I could make out ‘BUG ILY R’. There was rapid fading and the dash in the R was much fainter than the rest. Fainter but unmistakably there. I was positive about the R but being the cautious type and realizing this QSO would be an amateur radio first I really wanted to see it more clearly before declaring the QSO complete. The signal faded and nothing was seen for hours. Sunrise at 2E0ILY was fast approaching and I had to make a decision. Was I going to log the QSO or retransmit my RO message the following night in hope of getting better copy of the R on night six? Just before dawn the signal reappeared, very weak. I could barely make out ‘BUG IL’, then the ‘Y’ was quite strong. Given the proximity to sunrise every minute felt like an eternity. Ticking of the clock became offensively loud. It was going to take another four minutes to get an R! Would it hold up that long? Slowly, as the clock ticked and my heart raced, a crystal clear ‘R’ painted on the screen. There were traces of signal for some time after that but nothing¬† I would call readable, save a stray ‘Y’ that somehow came through well past dawn. So it came to be that shortly after 0600 UTC (1:00 AM local time) on this, the 28th day of March, 2018 I entered this QSO into my station log. We had done it!

QSL card received for this very memorable QSO!

This was an amateur radio first from the U.S. but nothing new in terms of distance on the 2200 meter band. Canadian stations, operating under amateur call signs but otherwise a program similar to our Part 5 licenses, had worked Europe years earlier. Much longer distances had been covered. But for me this was one of the most exciting QSOs of my nearly 40 years as a DXer. It ranks right up there with my first EME QSO, the QSO that put me on the DXCC Honor Roll and several other notable events such as being credited with the first North American two meter auroral E QSO back in 1989. My thanks to Chris, 2E0ILY for his time and patience to make this happen – not to mention the kilowatt hours of electricity expended.

DFCW may be old school but it gets the job done under extremely difficult conditions. DFCW ‘decoding’ is done by the human operator. Deciding what has been copied is not left to computer software which may use assumption or non amateur radio means to fill in things it couldn’t positively make out over the air. DFCW is painfully slow but here we had a very positive over the air exchange of full call signs, reports and acknowledgement without any shortcuts or fudging. I was very pleased with that!

Although this single QSO cost more than any other, this was a low budget operation. Most of the LF station consists of low cost kits and home built gear. Equipment used at my station for this QSO was the QRP Labs Ultimate 3S driving a home built amplifier to 175 watts output. The transmitting antenna was a 90 foot Marconi (vertical) with a top hat consisting of three wires each 100 feet long, spaced five feet apart. Three one inch diameter aluminum spreaders plus triangular wire sections at each end are electrically part of the top loading. This is resonated at the base with an inductance of approximately 2.3 millihenries. Loss resistance at the time was near 100 ohms, resulting in EIRP of 0.5 watt. For receive I used a 30 foot low noise vertical, band pass filter, W1VD preamp, and a modified Softrock Lite II SDR receiver. The amplifier and most of the receive system has been described on my blog and/or web site. There are photos of the antenna and variometer on my web site.

The Diminishing Amateur Radio QSO

I have always gravitated toward DXing and “weak signal” work. I am a very competitive DXer, sometimes contester, and like to push the limits of technology and skill to make difficult QSOs on challenging bands or using challenging propagation modes. I have 297 DXCC entities worked on 160 meters, 125 on 6 meters, 84 on 2 meters. I worked over 600 unique stations on 2 meter EME between the late 1980s and the early 2000s, all on CW.

What is a QSO? It is (or should I say was?) a two-way communication between two amateur radio stations. If we look back at the original definition of the Q signal, QSO means “I can communicate with ______”, where the blank would be the call sign or other identification of a particular station. It made sense to use this Q signal to mean “I have communicated with ______”. They key word is communicate. We are, after all, supposed to be communicators.

So how do we define communication? We had the concept of a “minimum” QSO for many decades. I am speaking here mainly about VHF and up “weak signal” QSOs. Our forefathers, in their wisdom, no doubt in recognition of the fact that we are communicators, realized some standard had to be set on what, at minimum over-the-air information exchange would be acceptable for a QSO to be considered countable for awards, etc. The standard they came up with was that both stations had to copy full call signs, signal report or other piece of information (such as a grid square), and acknowledgment that those things had been received. We had a clear standard definition of the minimum acceptable amount of communication which needed to take place over the air to claim a QSO had taken place. In all the years that I worked meteor scatter and EME on 2 meters and above, I never logged a QSO where I did not copy this information entirely, including both my call sign and that of the other station. Although in any competitive activity we can assume there are a few who bend the rules, I never had the sense that most operators were anything but above board in adhering to the minimum QSO standards. One could find the definition and standards for a minimum QSO widely published.

All of that changed when a new crop of digital modes came on the scene in the early 2000s. First we were introduced to the concept of “deep search”, wherein only about half of the calling station’s call sign need by received over the air for the software to claim a decode. The remaining portion could be obtained by finding the best match in a database of known active call signs stored on the computer of the receiving station. There was no community discussion or voting on this beforehand. One man made a decision that changed everything. The software with this capability was developed and released. It was immediately popular with a multitude of newcomers to EME who found they could now partake of the activity with much smaller stations, and by many of the old guard who were hungry for more QSOs. There were some, myself included, who felt deep search violated the minimum QSO standard and that such QSOs were incomplete, not valid.

Aside from ethical questions, we may ask how reliable is deep search? What if there are several similar call signs in the database, for example? What if the call sign we want is not in the database but a similar one is? I have conducted tests on a number of occasions. To use one as an example, I listened during the 6 meter EME DXpedition VK9CGJ. For some time I listened without deep search enabled. There were no decodes. I then enabled deep search but did not have VK9CGJ or any similar call sign in my database. There were no decodes. Then I added W7GJ to the database and immediately started seeing decodes of W7GJ calling CQ. Then I saw a decode of W7GJ sending me a signal report. This wasn’t possible, as W7GJ was the operator at VK9CGJ. Clearly deep search had misidentified the station because a partial copy matched part of this call sign what was in its database. I Where it got my call sign from I don’t know! I then entered VK9CGJ into the database and started seeing decodes claiming VK9CGJ was answering me and sending a signal report. But wait, it gets better. The signal report wasn’t even in the EME format. In other words, all of these were false decodes. Not just false decodes of a station calling CQ, but false decodes containing QSO information! I had not transmitted at all, so no one should have been calling me. If in fact he was calling me, it could only mean that a false decode had occurred on his end. I have seen similar results in other tests. Similar tests have been carried out by others, with similar results. To me it is very clear deep search makes mistakes. How is it that so many people accept QSOs made with this feature as valid, when the full call sign of the calling station has not been copied over the air? Perhaps almost as disturbing, I have received a number of QSL cards for 2 meter EME QSOs during a period of time when I didn’t even have a 2 meter station. Were these QSOs manufactured by the software?

Later we were introduced to modes which used a single tone (steady carrier) to “communicate” part of the QSO such as signal reports and acknowledgment. Since only a very brief instant of tone recognition was required for the software to claim a decode, this was obviously prone to false positives.

Lately we have another newcomer in the QSO shortcut features. AP (a priori) decoding uses already known information as a QSO progresses to augment decoding. Unfortunately it starts out knowing the receiving station’s own call sign, so this doesn’t need to be copied over the air. The decoder assumes the receiving station’s call sign is in the message unless it gets enough over-the-air evidence to prove otherwise or introduce significant doubt. At this time there would seem to be insufficient evidence on the reliability of this, but I have seen a number of people asking about stations calling them “in the blind” when they haven’t yet transmitted. One has to wonder if these are cases of the decoder assuming their call sign was in the message and then failing to find sufficient evidence to the contrary in a partially received message. Furthermore, on one very popular mode which uses AP decoding, everyone is strongly encouraged never to call someone on the frequency they are transmitting on, but instead to use split frequency. This further muddies the waters. If the usual operating convention were to call on the frequency of the station you want to work, that in itself would offer some clue (though not by any means conclusive) that you are in fact calling that station. But if you stations are calling on random frequencies, this clue is lost. It’s enough to make one wonder if this insistence on using split is just for further obfuscation to hide the truth about AP decoding.

AP decoding with split frequency is ludicrous! Suppose I were to call CQ on CW or SSB. I hear no callers on my frequency but I tune further up the band and hear someone give their call sign along with the some letters that might fit mine, such as “N1” and “U”. It would be ridiculous for me to assume they were calling me. Yet this is exactly what AP decoding does.

I find it very sad that all of this has been accepted with relatively few dissenters. I fail to understand how users of these modes, let alone organizations which issue operating achievement awards can consider such QSOs to be valid. But we are in a new world. For the most part, the definition of a minimum QSO has disappeared, especially the part which talked about full call signs having to be received over the air. Many operators clearly know what these features do and use them anyway. Given the obvious lack of understanding of basic concepts by many, however, it is likely a good number do not understand the shortcuts that are being taken by the decoder. Add to that the fact that we now have a new generation of operators who came into the game in the digital age and know nothing of minimum QSO standards as they existed before. We can clearly see this situation is long since irreversible. The bottom line is that today’s standard for a minimum QSO is closer to mutual detection of signal than a set quantity of over-the-air information exchange. Where will it stop? Are we headed for “QSOs” where only a hint of signal from the other station has been detected but no actual communication has taken place?

Digital modes using these features have largely taken over many aspects of DXing. EME went almost entirely to digital modes many years ago. More recently 6 meter DXing went almost completely digital. HF DXing is taking a strong turn in the same direction, as is VHF contesting. Proponents of digital modes say those who don’t like them should simply continue to use CW or SSB. That sounds reasonable on the face of it, but experience proves there is not enough activity on these modes to sustain a DXer, while at the same time many of the people busily working digital modes say they would rather be doing traditional modes or that they view the digital modes as a necessary evil.

There is perhaps truth to be found in the latter. Long ago EME reached a point where it was not worthwhile to build or maintain a station for the small amount of remaining CW activity. Now the same is becoming true for many other aspects of DXing. The sad fact of the matter is one either accepts the digital modes and the new definition of a minimum QSO or one leaves the DXing pursuit. One cannot be competitive without using the digital modes and most likely cannot find enough activity to justify having a capable station. That is the bottom line. I have been wrestling with this for some time. I have great difficulty taking any satisfaction from QSOs made on digital modes that shortcut the information exchange. Yet there seems to be no other choice if I want to use my VHF/UHF equipment for more than an elaborate home dust collection system.

It isn’t just digital modes that are changing the nature of the QSO. Nearly every day I see people talking about checking the online log of some DXpedition to see if they had a QSO because they didn’t hear enough over the air to know if they made it into the log. How sad. If I don’t hear enough over the air to know the QSO was good, then obviously it was not complete on my end! It doesn’t matter if I am in the DX station’s log or not — the QSO was not valid. But I am clearly in a minority with this opinion.

It seems we have moved away from being communicators, taking pride in building and operating stations capable of real communication. Instead we now look to any kind of mutual signal detection as a basis for claiming a “QSO” and/or award credits. It’s all about the glory with none of the substance. I am not the only one who thinks this is wrong. Many avid DXers having given up and left the hobby altogether. Others barely hang on, wondering if it is really worth it any more.

A Low Drive 2200 Meter Amplifier

Note 25 January 2019: The drain waveform has been corrected and this amp has run many hours at 250W output including some rather high duty cycle mixed WSR-15 / WSPR-2. It seems very reliable at that level. I will revise this post further when I have more time.

Note 12 May 2018: I have discovered this amplifier does not operate with a nominal Class E drain waveform. However that does not change the fact it has performed very well as described in this post. I intend to publish and updated version with corrected waveform at a later date.

While still planning and collecting parts for a high power 2200 meter amplifier I began to wonder if the design I use on 630 meters could be converted and made to work at 2200 meters – and if so, would I have the right parts to build it? Some quick math, assuming linear scaling of component values with frequency, showed that I just might be able to hit the correct values using parts salvaged from a problem ridden dual band amplifier I had given up on. So I set out to build and test a prototype. It took some fine tuning of inductor and capacitor values in the output circuit to get best efficiency and power peak at 137 kHz.

Schematic of the completed amplifier

Initially I used T106-2 cores for the inductors but in order to fit the required number of turns I had to use 24 AWG wire. Heating of the wire was excessive but otherwise the amplifier was showing a lot of promise. I decided to bite the bullet and order some T157-2 cores which would allow using 20 AWG wire. Note: heating of the wire in these inductors was not a surprise. My 630 meter unit does the same, as do several built by others. In the final design, it is possible to run high duty cycle at 100 watts output without a problem. For higher power I recommend a small fan blowing air across L1 and L2. It would probably be OK without the fan but I prefer to err on the side of caution. Capacitors C1 through C4 are made by connecting smaller values in parallel. I had a bunch of .01 uF 630 volt WIMA FKP2 capacitors and some 2000 pf 500 volt silver mica capacitors. These were the only two values needed when using the proper combination in parallel. The DC blocking capacitor is 2 uF, comprised of two 1 uF WIMA MKS4 capacitors in parallel. Initially I used a single 1 uF as in the 630 meter version but I found it was heating up slightly. Going to two of them in parallel resulted in no detectable heating.

The 22200 meter “junk box” amplifier

Construction is similar to the 630 meter amplifier discussed in an earlier post. “islands” were made by grinding away some foil from double sided FR4 material with a rotary tool and diamond bit. The finished amplifier can be driven with one milliwatt (0 dBm), like its 630 meter counterpart. Power output is similar. I measured in excess of 30 watts with a 13 volt supply, 110 watts with 24 volts, and 155 watts with 28 volts. In all cases, efficiency is 87 to 88 per cent. These figures hold over a range of 134 to 140 kHz. Outside that range it beings to roll off rapidly. I have been running mine for the past couple of nights at 28 volts and it seems fine. In the interest of disclosure I did have one FET die during testing but I had not been watching the antenna matching closely enough. Temperatures plummeted from the mid forties to the high single digits during that night of operation, causing the antenna resistance to drop sharply. This caused power output to soar above 200 watts before the FET finally gave up at 3:30 in the morning. I do not consider this a fault of the amplifier. Knowing how 2200 meter antennas are, the operator should have been watching more closely!

Update March 7, 2018: The amplifier has been running perfectly with no additional FET deaths. For more than a week I have been transmitting a combination of WSPR-15 (a good test for any amplifier) and WSPR-2 at 150+ watts output.

Update March 10, 2018: I cranked the voltage up to 30V and have been running the amp at 175 watts output for three nights with high duty cycle WSPR-15 and WSPR-2.