Springtime Lull

The bad spring weather continues. This has been the wettest early spring I can remember for perhaps 10 years. At least it has warmed up, although we still have regular cold weather. That isn't so bad except that it comes with high winds and snow. It is always amusing to see the tulip shoots pushing up through the snow cover. This weekend it was a summery 25° C on Saturday and snowing on Sunday.

About the only productive work I've done outdoors was several hours clearing brush along the Beverage lines in preparation for summer growth, and to take down several large dead maples that threatened the towers or buildings. Felling trees isn't so hard but cutting them up and disposing of the debris is a lot of work. I also spent time putting connectors on and testing Heliax runs that I hope to bury in a trench to one of the big towers either this spring or in the fall.

I did manage one tower climb to resume work on one of my projects. That was great until I fired up the station for the Ontario QSO Party and found out I had trouble with both prop pitch motor rotators. One wouldn't turn at all and the other had an intermittent direction pot.

Remember this uncomfortable truth with large stations: you can be as thorough as you like yet there are so many things that will go wrong. Maintenance is never ending, no matter how well you build it.

I've had time to operate yet admit to doing little. General chatting doesn't often interest me and there has been little happening on-air to attract me. I've been passively monitoring far more than I've operated.

• There are no interesting rare DXpeditions at present. 3Y0K brought excitement for a while and then there were S21ZD and XX9W, plus a few others that drew my attention. The latter were difficult due to being shots over the north pole. They seemed to have more luck with Europe and with FT8 so that's what they did. 
• Despite that difficulty, with daylight shining on the Arctic there have been regular openings most evenings to Asia over the pole, at least on 20 meters, and some on 17. The several days long dive of the solar flux below 100 bodes ill for 15 and 10 meters. The years long slide down to the solar minimum is well underway.
• 
  6 meters briefly showed signs of life around the spring equinox, as expected. I heard South American stations almost daily for nearly 3 weeks. That dried up in early April. In any case there were no new ones to work. There was a CE0Y station active but not on 6. It will be several weeks yet until we see the first glimmerings of the summer sporadic E season.
• 160 meters has been quite poor. Most evenings the Europeans are very weak. Even the FT8 activity is subdued. There has been little DX at our sunrise openings, just the occasional VK and KL7, with just one JA heard on FT8. I expect better with the quiet geomagnetic conditions at present. As previously mentioned I heard but did not work 3Y0K on top band. I could have tried harder but it was inconvenient. Soon I'll be rolling up the radials for the duration of the farming season.
• There are no major contests. The next is WPX CW in late May, which I may enter for practice since it's not one that I particularly like. The only QSO parties that interest me are the Ontario QSO Party, where I want to raises the activity level, and perhaps the Florida QSO Party since it is one with lots of activity. Handing out a mult was fun in OQP but the contest was otherwise not terribly exciting.

While the rain pours and the winds howl, keeping me off the towers, I am dabbling with various indoor projects. 

• 
  I made significant strides on the software for the next version of my antenna selection software. Although it won't be ready for a while yet I am getting close to connecting the new UI (user interface) to the Arduino-based antenna switching system. The design process has been interesting since the revised UI requires a different relationship between clients and server. I may write about it when the project is done.
• To support the antennas slated for construction this year and next I am preparing Heliax runs to the tower that hosts the 20 and 15 meter stacks. That tower also has a 30 meter delta loop and the tower itself is shunt-fed for 160 meters. A new trench will be required, running parallel to the one I dug 6 years ago. I'll toss a Cat5 cable into the trench for control line expansion.
• Most of the material for the new 3-element 20 meter yagi has been assembled. I'm thankful that the aluminum is on hand because, have you see the price of aluminum recently? Antenna prices are going up, commercial or home brew. It ain't easy being a big gun!

This article took me so long to finish that I finally did spend a few hours on the towers. Many more will follow as the spring weather stabilizes. I'm beginning to realize how much work there is to do this year. I'm getting exhausted thinking about it. The springtime lull won't last much longer. Then, if I feel lazy, I'll have different excuses to avoid work on the station, such as ticks and the growing hay.

Stray Capacitance in Interaction Models

Measuring stray reactance -- L and C -- can be difficult because the values are typically quite small. Yet that is a requirement I've dealt with when modelling antenna interactions. Test fixtures can only be built with some difficulty and then measured with suitable instruments, and I've never done that before. The literature addresses some of the cases I run into but not all. Then there's the matter of whether the quoted figures are reliable since the measurements methodology may not be described.

There are two cases in particular that I want to discuss since they are prevalent in my station and I've harboured doubts about my methods and calculations:

• Coupling of guy cable segments at insulators. There is coupling due to field interactions (naturally dealt with in NEC engines) and the series capacitance of the overlapping guy grips.
• Coax common mode leakage across transformers with galvanically isolated windings. I use lots of these in my Beverage systems, and I use more in long runs of RG6 lying on the ground that may be parallel to Beverage antennas for some distance. 

When I first developed interaction models in EZNEC for my guyed towers I modelled a wire for each non-resonant guy segment and overlapped by a length and separation approximately that of what was built. That was cumbersome and not really very accurate, but probably good enough. For the small Beverage transformers I represented the coax with connected wires and placed series capacitive loads on the wire to model the series capacitance between the transformer windings. I used values gleaned from ON4UN's Low-Band DXing and other sources.

The latter method of modelling stray capacitance is easier than the former, so I've been using it almost exclusively for the past several years. However, I don't know how accurate either method is or can be.

It struck me as an ideal small project to tackle during the extraordinary and persistently bad weather we're going through this April: rain, snow, wind, cold. There are always jobs to do in the shack and the workshop when tower work is too uncomfortable. I set out to measure the series capacitance in the cases listed above with the hope of designing better interaction models in the future.

I have a 1:1 Beverage transformer on a BN73-202 binocular ferrite core with 3 turns of insulated #26 wire for both windings. It was left over from a project and is identical to what I use for isolating coax segments in my long RG6 runs to the Beverage antennas. For the other case, I quickly constructed a "dummy" guy segment termination from a 504 insulator and two 5/16" guy grips. This is what I use on my big towers supporting stacked yagis and large 40 meter antennas.

There are 3 instruments that I have available for the measurements:

• RigExpert AA54 antenna impedance analyzer (single port)
• VNWA3 2-port VNA
• 35 year old LCR meter (made in Taiwan, and the brand is defunct)

I first did the measurements with the AA54. The results, at first, seemed sensible, but did not pass scrutiny. This shouldn't have been a surprise since these analyzers, even one of this quality, have increasingly poor accuracy as you move farther from its 50 Ω reference point. A pure capacitance in series with an infinite resistance (open circuit) has a very high SWR indeed. It is a poor LCR meter in these circumstances.

You may have to click on the image to improve the resolution. On the right are two measurements of the transformer, one open and one with the transformer in circuit. The ends of each winding are joined for the measurement of inter-winding capacitance. I compared the two calculated capacitance values with the expectation that their difference would be close to the actual value. In this instance, the difference fell between 2 and 3 pf: measurement precision is no better than 1 pf.

Notice that the R value is 0 Ω for all of the measurements. That casts suspicion on the results. The open circuit is so out of bounds from what this single port device can accurately measure that some deviation was to be expected. The measurement of the guy cable series capacitance is about the same, further casting doubt on the suitability of the instrument for this application.

I tried the measurement from 1 to 50 MHz in the hope that there would be an island of stability, if not accuracy, at least at low frequencies. At low frequencies the calculated capacitance was far too high, only stabilizing above about 5 MHz. So I chose 50 MHz and got the same result at a few other randomly selected frequencies. The poor accuracy really isn't the fault of the antenna analyzer. I asked it to do a job it was not designed for. 

I moved on to my old and trusty LCR meter. Like most of these instruments it does its measurements at a low frequency, although that is not documented. But I have had a lot of success with it over the many years I've owned it, measuring fixed and variable capacitors from a few pf up to a large fraction of a μF. A major downside of the meter is that it eats through 9 volt batteries very quickly.

The LCR measurements were quickly done with the aid of the short alligator clip leads. The stray capacitance of the instrument plus leads is slightly below 6 pf, so we subtract that from the measurements.

The results are far more in line with my expectations: 5.6 pf for the transformer and 11.3 pf for the guy termination. The Xc at low HF frequencies is close to what others have measured for a transformer of this design. That gives me confidence that these values improve my interaction models. Greater measurement accuracy may be desirable for capacitors used in antennas and matching networks.

I did not do measurements with the VNWA 3 at this time. With the many recent PC upgrades I made this winter it would take some time to set up the software to use it. The single port (S11) measurement would likely be better than with the AA54 but probably not by a lot. More accuracy requires a 2-port (S21) measurement of the series reactance, using a fixture that includes the outer coax conductor. Maybe when I have nothing better to do at a future date I'll make the measurements if only to satisfy my curiosity.

In practice there are many parameters that determine guy wire interactions, with the series capacitance just one of them. As you go higher in frequency the Xc falls enough that there is significant conductance through those guy terminations. For example, Xc of an 11 pf capacitor 30 MHz is just 480 Ω. It's 10 higher on 80 meters. Those non-resonant guy sections are not as isolated as they appear! Don't be surprised if they model differently than you expect when you include the stray capacitance between supposedly non-resonant guy segment.

There are also induced currents from the antenna itself and among the guy segments despite each segment being non-resonant in isolation. Perfection isn't possible: we can only do the best we can. I intend to use the LCR meter measurements in my EZNEC interaction models until I have better.

Is it worth the effort? I believe so. I've put enough years and sweat into my "big gun" station that it is only sensible to get the most from it. That doesn't mean I'll make major changes when an interaction is worse than I'd like, but I'll know what to expect. That's valuable information even if it isn't good news.

Ignorance is not bliss. 

Did FT8 Save Amateur Radio?

It was with some surprise that an article I wrote a few months ago went "viral". Well, viral as far as it can be within a limited population of hams. It has been the most popularly viewed article in the recent history of this blog. 

Digital modes court a range of emotional responses from hams that have been licensed for a long time. Newer hams just shrug and carry on. Digital is undeniably popular. Many of the public comments and private feedback to my article seem to have missed the point. I was drawing attention to the way the world is, not the way any of us might wish it to be. So, yes, digital has won. You don't have to like it.

At the risk of being seen as taking advantage of the controversy I will revisit it for a particular reason. It isn't for the financial reward since I get none from the blog. That reason comes from a throwaway comment made by a friend when we spoke recently. That's the source for the title of this article. We laughed it off, but I kept coming back to the question over the following days. 

It's worthwhile to flesh out the arguments pro and con. I might as well since I am unable to get any tower work done due to weeks of poor weather. The above photo was taken this morning. I envy those of you that don't experience spring snowstorms. Warm weather is on the way so technical articles will follow as I start into my long list of tower and antenna projects.

First, what if there were no FT8? What would have been the implications on licensee numbers and on-air activity? There is no way to know for certain. Instead we have to look at the evidence that exists, circumstantial though it may be.

Let's review a few facts, not all of which have hard data attached. I am not willing to invest the time to do extensive research for a brief article like this. Hopefully there are no significant errors:

• There are more hams in the world than ever before. It is certainly higher in Canada, the US and many Asian countries other than Japan, growing at rates faster than the total population. It may also be true in Europe, though not so much elsewhere.
• Towers for effective HF communication are being eschewed by new and young hams in developed countries for a variety of personal and societal reasons. That was not true decades ago. They prefer simple antennas, portable operation (e.g. POTA) or may avoid HF entirely.
• Few new licensees know CW and only a fraction of them learn or are planning learn. Yet phone and conversational digital modes can be difficult for those with small stations. Like long time hams, there is more interest in making contacts, DX or otherwise, than having conversations. Conversations take place off-air, even among hams.
• VHF/UHF FM is the gateway for many new hams, for local communication, public service and emergency preparedness. Many of them let their licenses lapse. A few of those that stay migrate to HF. 

It is a commonly held belief by many older hams that if there were no digital modes that new hams would be active on (what they like to call) "human modes." That is, where a computer is not an active component of the QSO. This mainly is meant to mean CW and SSB, although some will include RTTY and other computer encoded/decoded modes that permit conversations or data communication.

Is that true? We can only speculate since there is no way to do an experiment. Take a look at the waterfall spectrograms shown in that earlier article that caused such a fuss. Do you believe all those FT8 signals would transfer to CW and SSB if we auto-magically and retrospectively eliminate digital? In my frank opinion, no, that would not have happened.

There are few conversations taking place on HF. Most are "599" DX QSOs or POTA activations. Those that are actual conversations are between hams of long acquaintance who have a regular schedule or participate in so-called nets. If we restrict our focus to CW there are even fewer conversations, and those are typically not between or with new and young hams.

CW won't die but it will become a niche mode. SSB will continue since it is easy. Few new hams that are solely on FM will stick around, or will find their niche there and stay there.

Digital modes, FT8 in particular, are undeniably popular. New hams with small stations can work a lot of DX on HF, and they do! They really enjoy it and have been bitten hard by the DXing bug despite the naysayers. It doesn't interest me as a contesting mode though some promote it as such.

That said, is there an attraction for a digital-exclusive HF operator to spend more time on SSB and to learn CW? The answer is yes. Many are learning CW to improve their POTA results, mix it up in the pile ups and to become more versatile contesters. It has been said (and I agree) that CW is an ideal contesting mode.

Of course, many of those using digital on HF are unlikely to ever learn CW and they are discouraged by attempts to DX with SSB from their small stations. We are well below replacement numbers on CW, so its use will decline as elderly hams depart. It has had a wonderful 100 year run but now its time has passed. SSB will continue as a DX and contest mode and for some conversation. FT8 will likely be a mainstay for general operating and DXing on HF for many years to come. However, we can't reliably predict far into the future. Time will tell.

I've droned on for longer than I intended. But it's relevant to the original question: did FT8 save amateur radio?

If we restrict ourselves to HF, I am leaning towards yes. I'm not convinced but I am persuaded. Had there been no FT8 (by far the most popular digital mode on HF and VHF) those hams currently active on FT8 would not be on CW or SSB. The spectrogram of a CW band segment like that in the earlier article would likely look very similar.

That's not the end of the story since FT8 does more than just increase activity at 7074, 14074 and the other FT8 watering holes. Once these hams get hooked on HF, DX or POTA, their ambitions grow. Many hams new to CW and SSB have migrated after being almost exclusively on FT8. SSB first, of course, yet many are learning CW. Why? What incentive do they see?

The answers are various, with no one overriding reason. The following are ones I've personally heard from newer no-code hams. Keep in mind that these observations do not comprise a statistically valid sample:

• The challenge of learning and becoming proficient at the code
• Improve results in radiosport activities: POTA, SOTA, DXCC and contests
• The high rate potential in competitive contesting
• Relatively simple home brew CW equipment for the technically oriented

Communication isn't in the list since that isn't the attraction in 2026. It seems to only attract a minority of new hams. Again, it isn't about what ought to happen (however you may feel about it) but what is happening.

There is a story in the current (April-May 2026) issue of the National Contest Journal about one relatively young ham, WM6Y, who took the CW challenge after spending time on FT8. You have to be an ARRL member to read the article so I will quote a few sentences:

"Do not dismiss digital modes. They can be a gateway, not a replacement. Sometimes the path to CW does not start with a key. Sometimes it starts with a computer screen — it did for me. FT8 brought me back to amateur radio. It motivated me to upgrade my license. It led me to portable operations and ultimately to CW. Without FT8, I might never have returned to the hobby at all."

In his case the activities were POTA and contesting. That agrees with my experience talking to newer hams, as I mentioned above.

Digital isn't so bad, so cheer up. These modes can contribute a great deal to the future health of the hobby, whether or not hams decide to later migrate to CW and SSB. I regularly use FT8 on 6 meters and a few other cases, despite initial reticence. I guess you could say I took the opposite migration path: from CW to digital. 

The future is potentially bright for our beloved hobby, and digital may be an important reason why.