One Screw Defeats Two Antennas

When we left the 30 meter delta loop I mentioned that it had to be disconnected for the time being. The reason is that it did not have a feed line. Instead I used the one for the 160 meter antenna (shunt fed tower). To conserve Heliax my intent was to have them share the same transmission line. That required a way to switch between antennas at the tower base. It's an economical arrangement since those antennas are never used at the same time; 30 meters is not a contest band.

Switching up to a kilowatt in a low impedance (50 Ω) system is conveniently done with an 8 to 10 amp modular relay. I keep them in stock for applications such as this. I selected a 12 amp SPDT relay, the same device I use in many of my home built antenna switches. "Dead bug" style construction is ugly but it works fine in this application. No one will see it with the enclosure cover in place.

The enclosure at the tower base was previously drilled for 2 auxiliary antenna ports (UHF chassis connectors), so I removed the tape from one of them and installed the connector, relay and flyback diode (1N4007).

The default path is the 160 meter antenna. There is no external connector for it since the enclosure includes the gamma capacitor and connections to the gamma rod and ground. When the relay is energized the RF path switches to the 30 meter delta loop. 

When (if) I add another antenna port, a second SPDT relay will be added. The relays would be chained by taking the wire to the 30 meter connector to the second relay, which would switch between the two auxiliary ports. That is, to select 30 meters the first relay is energized and to select the other auxiliary port, both relays are energized. There is negligible impedance "bump" at HF from this circuit.

The configuration of the antenna selection software was changed to select the delta loop on 30 meters and manage contention in case two radios (SO2R or multi-op) attempt to select more than one of the antennas on the transmission line.

If you've read this far you may be thinking that this is routine and hardly worth writing about. What's interesting about relays switching RF? It's done all the time. Despite hinting that I would write an article about the 30 meter antenna switching I had no real intent of doing so. What changed my mind was what happened a couple of weeks later.

The antennas and switch had been working well. Then one morning they weren't. Both antennas showed high SWR and poor receive signal strength. On a warm and sunny weekday morning I grabbed a few tools and my antenna analyzer and walked across the hay stubble to discover what was going on.

There were no obvious problems. The antenna analyzer confirmed that the transmission line was okay and that the trouble lay inside the enclosure. There were no visible faults when I opened it. The DMM confirmed that the relay was operating and the RF paths were fine. This had become very puzzling indeed.

Since the enclosure is non-conducting I moved on to test the ground wiring.  Unlike in a metal enclosure those wires are necessary. 

When I measured the resistance from the ground lug (bottom centre on the right panel above) to the transmission line connector flange there was an open circuit. How was that possible? The trouble spot is pointed out by the blue arrows.

The picture above shows what it looked like after the repair. At right is the #4 screw that I replaced.

There is rust on the screw head, top and bottom, and the first couple of threads. The rust acted as an insulating layer between the screw and connector flange, both it's outer surface and the screw hole interior walls. I used plated screws since they were handy at the time. But I did not replace them with 304 stainless screws that I bought this summer for this very purpose. I forgot.

As already mention, for a plastic enclosure there is no automatic ground path from the connector flange. It must be explicitly wired. The flange screws are critical since the solder lug, which is wired to the earth (and tower) grounding lug, must have a solid electrical connection to the flange. 

I opened the box of stainless screws and replaced the rusty one. That fixed the fault. I'll have to do the rest, just in case. Although not all are used for ground connections, it's sensible to replace them all. Stainless should not be used everywhere but when you need it, you need it. The corrosion deposited on the silver plated N-connector flange was removed by light buffing with steel wool. 

Even the biggest antennas can be defeated by a tiny screw. Don't overlook their importance.

Sanity Checking an Antenna

It is no simple matter to raise a large antenna onto a guyed tower. I've done far more than most hams and I still have to carefully plan and execute every step. From small yagis to the truly gargantuan, I've lifted them onto free-standing and guyed towers. I am well aware of the dangers so that the risks to property and people are always at the forefront of my attention.

It is aggravating when I and my friends make the effort to raise a beautiful big yagi onto the tower and find that it does not work. What can you do? Some problems can be fixed in place while in many cases, especially the largest antennas, it has to come down for inspection and repair. It should be obvious that the risks of raising and lowering antennas multiple times are greater than doing it once. Not to mention the annoyance of the friends taking time out of their lives to help.

Since antennas need to be well off the ground to work properly, testing and repairing large yagis on the ground might seem unlikely. While true there are still many tests that can be done on the ground. These include mechanical and electrical inspections. In the latter category are continuity tests, coil and trap tests, matching network tests, among others. You do what you can and then up it goes, hoping for the best.

Commercial antennas are easier to deal with than those you design and build. If you build a commercial product according to the instructions the antenna ought to work. They've done the hard work for you ahead of time. For home brew antennas you must deal with both construction issues and electrical design issues. There are more trouble areas to contend with.

However, what I driving toward is that testing an antenna is different from adjusting an antenna. What I am about to propose is the former, not the latter. For the moment let's assume that the antenna is properly adjusted, whether by following the instructions that come with a commercial product or a home built antenna that has been previously adjusted but is now on the ground.

I have previously described the design and construction of this symmetrical and reversible 40 meter Moxon yagi. Although the antenna worked and its performance closely matched the NEC5 design, the reversing function did not work. I had tested the individual components before assembly but did not do a full antenna test before raising it. I was in a hurry at the time to get it out of the growing hay. Better to raise and use it rather than disassemble the antenna and try again after the harvest. I got a few months of use out of it so the effort was worthwhile.

I gathered a crew and lowered the antenna in mid-August before heading to Manitoba. When I returned I diagnosed several electrical and mechanical issues and made repairs. This time I took the time to do a full antenna test before gathering my friends for an antenna raising.

But how can you do a full system test with the antenna on the ground? This is where we need to clearly differentiate testing and tuning: the antenna is already tuned (adjusted) so we just need to test it. The antenna has to be high (relative to wavelength) to be tuned, but not a test as a basic sanity check.

As pictured and tested, the Moxon is about 50 cm off the ground, with capacitance hat tips even lower. Even so it can be tested -- sanity checked. Although its behaviour will be very different than what you will measure when it on the tower, it will still "work".

First, the resonant frequency will be lower, perhaps much lower, due to ground coupling. In a sense, near fields are slowed due to the VF (velocity factor) of the soil. The amount is unpredictable but not too important for this type of test. Hook up your antenna analyzer and sweep through a large spectrum below its design range.

Second, the impedance at resonance will not be 50 Ω. Expect a higher SWR. In most cases the SWR will be moderate so that its ground-proximity impedance curve will remain recognizable.

Third, don't expect a directional antenna to exhibit the same pattern as it does in the air should you attempt an on-air test. Efficiency will also suffer due to ground loss. For a sanity check these attributes are of no great interest except insofar as excessive loss will push the SWR curve higher and may not display properly on the analyzer. In my experience this is rarely a problem. 

Sanity tests can be done for many kinds of antennas. I've done the same with tri-band yagis a meter or two off the ground. When properly constructed there will be clearly identifiable SWR dips below the 3 typical band ranges. 

In another case a ham acquired an older model tri-band yagi. There were no identifying marks remaining on the traps and a visual inspection was inconclusive. I suggested some quick experimentation by random arrangement of traps, one element at a time, sitting on trestles, and do an SWR sweep. When the element shows the expected SWR dips, set it aside and move on to the next one. Testing goes faster as the pile of traps gets smaller. 

This is an SWR sweep of the Moxon on the ground in its normal (forward) direction. The impedance is pretty good despite the almost 20% lower frequency. 

Next, I hooked up a battery to the reversing terminal to test it in its reverse direction. This time it worked. The sanity check was successful.

Notice that the SWR curve is not quite the same as in the forward direction. It's ~25 kHz higher. This could be a real difference or due to different ground characteristics under each element or slight height differences. The antenna would have to be lifted at least 0.1λ to discern whether the difference is real.

I didn't do that last test. The sanity check was good enough that I called my friends over this past week to raise the antenna. This time the antenna worked as it should when it was mounted on the tower, in both directions. The small discrepancy between the forward and reverse directions was still there so this was no testing anomaly due to ground proximity. The 25 kHz shift is most likely due to the reflector coils in each switch box not being perfectly identical. It isn't enough of a difference to worry about.

The 40 meter reversible Moxon is a heavy and awkward antenna so I hope that it continues to work. I'd like to avoid lowering it again. On the first evening of use I learned quite a lot about how it performs and compares to the 3-element yagi at twice the height. Many nights will be needed since propagation elevation angles and low angle absorption change day to day and even hour to hour.

Once I have enough experience with it I'll write an article on the antenna's performance. There is enough innovation in the design that might inspire others to emulate the antenna whether for 40 meters or other bands. This has been and continues to be a very interesting project. It was also illustrative of the advantages of sanity checking a large HF yagi on the ground.

Tower Trip to VE4

A confluence of motives convinced me to load the car with my climbing gear and drive to Winnipeg in late August. I've had several polite requests to do tower work for friends back home (Winnipeg is my home town). As elsewhere, there are fewer hams willing and able to do tower work and commercial alternatives haven't worked for them for a variety of reasons. The car was also packed with items from a deceased relative to be handed off to family. This is not the first time I travelled to do tower work.

Although it's a long drive (over 2200 km), with so much to carry it was not practical to fly. A large part of the drive north of Lake Superior is rugged and very beautiful, and I wanted to do it one last time. I don't expect to take the land route again; future visits will have to be by air.

As any contester will know, there is not a lot of contest activity from VE4. There was more when I was a young man, or at least that's how it seemed to me. Aging of the ham population and slower adoption of contesting by the younger generations of hams is as true there as elsewhere. This is despite the growing population of the province and of Winnipeg in particular (approaching 800,000), and growth of the overall ham population. There are many hams but most activity is on VHF, UHF and higher, focussed on technology and data networking. HF activity has declined. Again, that is no different than elsewhere.

In this article I'll talk about towers and antennas, and about some of the hams I met with. I apologize for the lack of pictures of hams in this article. I was focussed on towers and antennas, taking pictures on the tower but not off. While I will use what I found as topics worth discussion, as a matter of privacy I will not say which station belongs to whom. Not all belong to contesters.

First, the people. I was invited to the RSM (Radiosport Manitoba) annual BBQ. There were 12 attendees, not all contesters but certainly enthusiastic and active operators.The host was Gary VE4YH. Although his call may be unfamiliar to contesters, he hosts remote operators for contests. The station is larger than most though still modest. On his tallest tower he has a JK 3-element coil loaded 40 meter yagi that works very well from what I was told.

While the burgers and dogs sizzled on the grill I gave a talk on the building of my station. It's one I've presented a few times, updated to keep in step with the continuous changes that I make.

Perhaps the best known contester who drove in for the BBQ was Todd VE5MX. Surprisingly it was our first "eyeball" QSO. We had an interesting chat. He is headed to the WRTC competition in England next year (2026). His own station (re)building pace has slowed while his crew -- daughter and son-in-law -- start their family. Todd is a proud grandfather despite the wait for his crew to return.

My oldest ham radio buddy and fellow contester is Rob VE4GV. You'll hear him most often from PJ2T, portable /6Y, and occasionally from his own suburban station. He has quite a story to tell, which is related in great detail on his QRZ.com page. My original call (VE4OY, since reissued) shows up a few times.

Jessy VE4JBB/VE4DX is relatively young compared to most contesters. He has a tower and wires at his father-in-law's farm outside of Winnipeg. We can expect to hear more from him in the future. For now he is busy raising a family and his job in the IT sector. He gave me a few ideas for accelerating software development for my station projects by using AI tools. I'll have to explore that, but I admit to having doubts.

Barry VE4MA has long been a pioneer in EME and the microwave bands, with his exploits and record attempts published widely. I got my first and only experience of EME by listening to echoes of him pinging 432 MHz signals off the moon. That was in the late 1970s while I was in university. He continues to be very active locally and at his winter home in Arizona.

Cary VE4EA organized my tower work schedule while I was in town. My trip came about when I reached out to him to find a local tower climber who could help an elderly ham in Winnipeg. One thing led to another and off I went. Cary operates contests remotely since he lost his tower in a storm several years ago. During winter he occasionally joins multi-op teams at various stations in the US southwest.

Cary also arranged a visit and tour of Winnipeg Seniors Amateur Radio Club: VE4WSC. It is in an old fire station that was gifted to RAM (Radio Amateurs of Manitoba) for their use. There is a lot of space for meetings, stations (VHF, UHF and HF), workshops and a variety of radio and networking equipment. It's on a prime strip of real estate on a major thoroughfare and bordering the Red River. I imagine that any club would drool over this extraordinary facility. A picture of the fire station and its complement of antennas can be found using the above link.

The main purpose of my visit was to discuss HF antennas, specifically what might be possible. Since it's a city owned building any towers or other building attachments must meet their standards. The fire hall brick tower is in poor condition (the building is old!). The roof and masonry had to be reinforced just to support the Hy-Gain Explorer 14 yagi and other antennas. There are wires for the lower HF bands.

They will likely need to install a tower higher than the building (70'+) adjacent to the building to improve their HF capability. They can't make that decision on their own since the installation will have to be done by professionals approved by the city. Perhaps the bigger problem is lack of interest in HF by most of the local hams. They have a modern and sophisticated station that sits idle most of the time. It's available should an emergency arise but it could be used for so much more.

Now let's talk about towers. 

After my recent tirade against the excess enthusiasm hams have for nylocs I will now address another obsession: stainless steel. It is a myth that stainless hardware is always superior to more prosaic steel fasteners.

There are 3 critical questions to ask before selecting stainless fasteners:

• Alloy
• Strength and toughness
• Galvanic corrosion when in contact with other popular metals, especially aluminum 

At right is a thrust bearing where the steel set bolts were replaced with stainless. F593C was stamped on the bolt heads, which is not very specific with respect to alloy and grade. They were seized within the thick cast aluminum bearing housing. They were too tight to the mast to jack up the mast and antennas (400 lb) to access the rotator.

After liberal dosing with penetrating oil, two of the bolts heads still sheered off when forced with a long wrench. The third reluctantly turned. That was enough to jack the mast. There was an ample coating of "white dust" on the embedded bolt threads due to galvanic corrosion. It is almost always the case with most stainless alloys in contact with aluminum. Choose suitable alloys and lubricate stainless hardware. Otherwise prepare for future trouble. 

I replaced the bolt with a fully threaded grade 5 bolt. Also, those locking nuts really ought to be outside the housing, not inside. Those, at least, all turned with the help of penetrating oil.

While we're on the subject of thrust bearings, let me counter another popular myth that I've mentioned more than once on this blog: do not support the mast and antennas dead load with the thrust bearing. These devices are almost universally designed for radial loads only. 

Too many have their lifetimes cut short due to this persistent myth. I've seen this happen more times than I can count. Don't let yours end up like the one at right. They are not easy to remove and replace!

There are industrial bearings rated for both axial and radial load, but those are not the ones typically marketed to hams as tower thrust bearings. I have several of those bearings to support massive antenna systems to protect the prop pitch motors (rotators) from radial and axial loads.

Place the load on the rotator where it belongs. Rotators have all those bearings and large diameter races to withstand hundreds of pounds of axial load and even a substantial bending moment. A polymer sleeve/bushing is usually more than sufficient to hold a mast in place -- a bearing isn't necessary and a bushing is easy to repair or replace. But I am under no illusion that this article will extinguish thrust bearing myths. I expect that the myth will outlive me.

For some reason I've found myself repairing a number of old Moseley yagis this year. The driven elements are difficult to work on since the screws that secure the coax pigtails also provide mechanical support for the element halves. This one uses a cable tie and wire as secondary supports to ease electrical work. It's ugly but it works. I had to redo the setup to replace a cracked insulator and severely weathered coax and rotation loop.

My very first yagi was a TA33jr (same as the one above) back in 1975. I'm not nostalgic and I still don't like them for their poor mechanical design and lossy traps. But they sure have a lot of satisfied customers. Unlike so many other antenna companies, Moseley is still in business and selling many of the same antennas they did decades ago. 

Trylon self-supporting towers are very popular in Canada. They can handle smaller yagis and quite large HF stacks depending on the tower model and height. As you might expect, many hams put far too much on top. When the tower fails they blame the tower rather than themselves. Optimism is nice as long as it doesn't blind you to the realities of mechanical engineering.

The most popular Trylon self-supporting tower among hams is the Titan series -- I have one. For more demanding applications the more expensive Super Titan series is occasionally selected. Price, weight and foundation requirements must be considered before selecting any tower. A realistic assessment of wind load for your area is vital. Destructive prairie winds can rip across the landscape when you least expect it. The winds laugh at hams and their towers.

I saw a couple of Trylon Super Titan towers during my stay in Winnipeg and worked on one of them. Since the diagonals have a large slope, optional pegs are attached to one leg for climbing. Although this is an awkward way to climb a tower it is far better than dealing with the steep diagonal struts. Steel soled boots are mandatory.

Self-supporting tapered towers are stressed in predictable ways. The most common experience is bending stress due to the wind load (lateral force) of yagis at the top. When the legs yield it typically occurs about ⅓ of the tower's height from the top. Depending on the installation details, the failure point can be a little lower than that, but probably not below ½ the height.

A Trylon tower that has been stressed in this fashion may exhibit bent struts (structural members between the legs on a tower face) where a future failure is likely to occur. That's a danger sign that I've seen on far too many ham towers. The struts (or diagonals, if you prefer) can be replaced if you can find a source. If lightly bent it may be possible to bend them back into shape; any more and the tempered steel will be weakened. These measures can buy you time but that's all. I advise tower owners to reconsider the entire installation.

There are other failure modes. One is torque due to wind action on the yagis; most yagis are not symmetrical with respect to wind surface area and can build up a lot of momentum due to oscillations and wind gusts. In this case the tower usually fails at or slightly below the rotator. The struts at that location often do not show bending stress before the legs fail. 

A less common failure mode (in my experience) is due to bending stress on the top section(s) when the mast is stronger than the tower. The struts above the rotator will likely be bent. 

I've found many installations where the owner insists on the strongest chrome-molybdenum mast available and places it in a tower of far lower strength. That is guesswork, not engineering! A strong mast won't save your tower. I am speaking from experience.

The adjacent picture shows upper section bending stress on a Trylon Titan tower I inspected during my trip. The same damage was found on all three tower faces.

The tower is old and there are two large yagis on top. I'm surprised that it hadn't already failed. As you can see this is in a tightly packed suburban area where failure poses significant risks. I suspect the tower lasted this long due to wind shadowing by the many mature trees in this old neighbourhood. Trees don't grow fast in cold prairie soil.

I gave the tower owner a few ideas on how to deal with the problem but there was nothing more I could do. Any solution will be difficult and expensive. Ideally the tower be taken down and replaced with one engineered to survive. 

I'll end with a story of tower rust. Towers don't rust quickly on the cold and dry Canadian prairie. A similar badly rusted tower of the same age where I live could still be rust free in Winnipeg. 

If the rust doesn't go deep it is easy to repair. Remove the loose stuff and use one of the available paints to coat the damaged area. It can be a messy job on a tower, especially using spray paint.

I was fortunate that the wind was light and in the right direction to allow application of a cold galvanizing spray on this minor rust damage without getting any on my clothes. For my own towers I wait for favourable weather, a luxury I did not have on this busy trip.

I hope to be back to a regular schedule soon. Too much has been going on this summer. I have a lot of tower and antenna work to get done before winter and the major contests.

Phone Contest Phonetics

Copying errors are rife on CW. We expect it. After all, CW is an acquired skill later in life unlike speech which we all learn at a very young age. Also, we've evolved to handle speech well, not the rapid patterns of monotone dots and dashes. 

A high dot-to-dash ratio in many characters and words is a common cause of errors, both sending and receiving. I have spoken about my mostly futile attempts not to have my call miscopied as VE3UN and similar errors during contests.

Copying errors on phone are just as common but of a different character. Techniques to minimize errors are as old as radiotelephony. There is lots of noise and interference to contend with, distortions due to limited audio bandwidth and dynamic range, and audio transduction imperfections (microphones and speakers/headphones).

One of the oldest techniques to reduce errors is phonetics. We use them for call signs and other critical information that must be spelled out character by character, when accuracy is more important than speed. There are standard phonetics, such as the ICAO alphabet, among others. Inventing cute phonetics may be amusing, just don't try it in a contest if you want a good rate.

Stick with the standard phonetics which have been time tested to be effective. Not perfect, just better than alternatives. These have several important advantages:

• Unambiguous: phonetics are distinctive and therefore unlikely to be confused with other letters
• Multi-lingual: pronouncable and understandable to native speakers of most European languages, and many others
• Noise resistant: they have a distinctive "punch" that do better under conditions of QRM and QRN, and when the SNR is poor

One advantage they do not have is brevity. That matters for contesters. Some phonetics (e.g. Uniform) have 3 syllables. There is a trade off between brevity and effectiveness. As contesters, there is an advantage to call signs that are quickly voiced using phonetics. Yet there are only two in the ICAO alphabet that have just one syllable: Golf and Mike.

You might find it interesting to compare a call sign lengths in syllables. Obviously the fewer characters in a call sign the better, so let's compare with 5 character calls:

• Victor Echo 3 Victor Norway: 9
• November November 1 Sierra Sierra: 13
• Golf 3 Mike Mike Golf: 5

Of the numerals, only 7 and 0 have more than one syllable. This is unlike CW where the numerals can be the longest characters to send. However, that single syllable can be dangerous since they are less likely to be copied correctly than 2 and 3 syllable phonetics. Repetition may be required. Extending a numeral to 2 syllables -- e.gl Niner -- will confuse many operators, especially non-English speakers.

Deviations from a standard alphabet are effective in select cases. One example is to use Zed rather than Zulu. Nevertheless, an unexpected phonetic can result in a request for repeats. It can be very worthwhile to experiment with phonetics in your next phone contest to determine whether they are effective or not. You'll have to do it in a DX contest to ensure you get a mix of operators with a variety of native languages.

When one phonetic doesn't work it can be helpful to alternate or substitute others. Victor and Echo work well for me in the prefix, while Victor and Norway in suffix often do not. I can stretch each to 3 syllables by voicing Victoria and/or November instead. Again, experimentation is key. 

What works for one contester may not work for another due to pitch (e.g. YL ops), accent, and the native language of the copying station. In an earlier article I noted that ocho for 8 is more effective with South American Spanish speakers, but oddly not for operators in Spain.

To speed up my call I have tried V E 3 Victor Norway in several contests both for running and S & P. Since the prefix is pretty common I judged this to be an effective contraction. It isn't; requests for repeats increased to an unacceptable level. I no longer use it. 

Simply speaking faster increases copying errors. The same is true on CW. Depending on your call sign and the contest exchange there may be opportunities to speed up all or parts of these messages. It is easy to program in CW function keys, and perhaps that will eventually be done for SSB and TTS messages.

Stations like PJ2T can skip phonetics entirely since they are so well known and a desirable multiplier in most DX contests. It's hard to do better than 4 syllables for an unambiguous call sign. Unfortunately for the rest of us, we must stick with phonetics.

The topic of phonetics came to me as I was reading about the TTS (text to speech) feature that is soon to be rolled out as a new feature in N1MM Logger+. There are a variety of voicing issues being addressed. One of those is phonetics. The ICAO alphabet is being implemented but there could be others in the future. 

When we begin operating SSB contests like we've become accustomed to for CW it is very likely that scores will increase due to less mental strain operating SO2R and even 2BSIQ. But it won't happen quickly or smoothly. There will still be many times that the operator will have to step in, far more than for CW. It'll be interesting to watch. 

Inevitably I'll try it for myself. First, the smaller contests and then we'll see. I may try it for the first time in the upcoming contest season.

Nylocs: Overused & Underused

I ought to write more about fasteners. We use them by the dozen, and even by the hundreds and thousands in a large station. They're ubiquitous. I sometimes buy them individually, though more often by the box. Common ones I can buy at local specialty stores, less common ones I buy online or through contacts in the tower business -- there are suppliers that won't sell retail.

The purpose of a fastener, no matter the type or the material, is to hold things together. They may be metal plates, round tubes, combinations of both, wires, and more. Those used outdoors must survive the rigours of wind, rain, snow, sunlight, corrosion, axial and/or shear loads and so much more. It is no wonder there is so much variety on the market.

Unfortunately for us, fasteners fail. Sometimes it's a mechanical joint and other times it's an electrical connection. The former can pose a safety risk while the latter can render an antenna, and even your entire station, unusable. We want our fasteners to keep things fastened!

Hams usually don't come into the hobby with a deep knowledge and understanding of fasteners. I certainly didn't. We stumble along, using what comes with the products we buy, doing what other hams do or just buy whatever we can find at the local hardware store. 

When a fastener fails we have a tendency to overcompensate during the repair. A common aftermarket choice is the nyloc. They are included in many modern HF antenna products. And why not? They often do a fine job on our towers where vibration and weather shake loose more common fasteners. I use them a lot in my own antenna designs and I have replaced nuts on commercial antennas with nylocs when the need arose. I like them.

They are most useful in specific applications:

• Vibration
• Thermal cycling
• Round surfaces, such as tubes
• Joints that are tightened once and are difficult to access afterward

Some hams, encouraged by initial success, start to use them everywhere. That can be a mistake. In many applications they can cause more problems than they solve. It is not a universal solution to our fastener woes. There is a large variety of fasteners for that very reason. Each has its range of application. 

Here are a few items to consider before choosing to use a nyloc:

• Material: Are the nyloc, bolt and work surface compatible? A poor choice can lead to galvanic corrosion, galling, erosion and difficulty removing the nyloc at a later date. I almost always see stainless nylocs used since they are most commonly stocked. Even stainless on stainless can be a problem since different stainless alloys don't always play well together.
• Grade: The nuts and bolts should be the same grade, for example grade 5 steel and 304 stainless. Otherwise threads can be stripped, they can gall and occasionally fail during tightening or later when under load. Nylocs must be carefully selected as for any hardware.
• Ease of use: I have seen nylocs used in place of the manufacturer's recommended fasteners for splicing tower sections. That may seem like a good idea but really isn't. First, you will rarely see stainless fasteners spec'd in this application, and there is good reason for that. Shear loads have their own requirements. The choice of nuts also matters. Have you ever tried to assemble or disassemble a tower that uses nylocs? It is very fatiguing when hanging off the side of a tower. The reason is that high torque must be applied on these large fasteners for many rotations of the nyloc rather than just for a moment for an ordinary nut and lock washer. 
• Reuse: Nylocs can be reused within reason, and I do. But for how many times? There is no reliable answer. Do you really want to bet on it holding after using it for the third or fourth time? I've discarded nylocs while attempting reuse because when I judge that they didn't grip properly. When in doubt throw it out.
• 
  Plastic surfaces: Nylocs to secure electrical connections on plastic enclosures are often problematic. One example I've run into several times is the Cushcraft XM240 balun. The studs that connect to the driven element grip the enclosure with a conventional nut and lock washer, while the wire lug is secured to the stud with a nyloc. The large torque over many rotations of the nyloc caused the inner lock washer to abrade the plastic so that the studs loosen. In my experience it is a common cause of intermittent connections. The feed point is out of reach so the antenna may have to come down for repair. I've seen the same on other products and on my home brew projects.

If not a nyloc, what are acceptable alternatives? As always, it depends on the application. There are so many alternatives that it can be dizzying. 

Luckily only a few suffice for the range of applications that a ham is likely to encounter. Here are some that I use, or that I've encountered but don't use.

• Lock washer: This is hardly surprising since it's the single most popular device for securing a nut on a bolt. The problem is that there are so many types. Spring and star (internal or external) are the most common, and it is unusual to bother with others. 
• Keps nut: These clever devices have an exterior star lock washer incorporated into the nut. They are specified on a variety of Trylon towers that are in wide use in Canada and in the US. They occasionally show up in other products. Large specialty stores will have them, but otherwise you'll have to order them online.
• 
  Jam nut: Instead of a lock washer, a flat washer and two nuts are used. The outer nut is the jam nut. It can be an ordinary nut but there are special nuts made specifically for this application. First you tighten the inner nut as usual then, holding it fast, tighten the jam nut against it. Contacts tell me that jam nuts are becoming increasingly common in commercial tower projects in lieu of lock washers.
• Chemicals: Probably the one most have heard of is Loctite. There are many varieties on the market from them and other suppliers. I never use chemical locking compounds on towers and antennas. Indeed, I am more likely to use a long-lasting grease on threads to retard rusting, prevent galling (stainless) and ease removal years later. A properly employed fastener will hold fast when lubricated.
• Compression clamps: These include hose (or gear) clamps, while others use a conventional bolt and nut to tighten the clamp. They are mostly found on telescoping antenna elements and light duty mast. They are easily damaged by excess torque so use them with due care.
• Wired nuts: They are often specified in high vibration environments such as aircraft. Prop pitch motors use them. Most hams discard them when servicing old equipment since they are difficult to reuse or replace once disassembled. The matching bolts have holes through which the wires pass.
• Thread deformation: For nuts that will never be removed, the bolt threads emerging from the nut after final tightening are deformed with a hardened tool. The nut can't come off, ever. I've seen this technique occasionally used on commercial tower splice bolts. Those towers are meant to be cut down at the end of service life, not disassembled for reuse.

That was a very long-winded way to explain why nylocs are not a universal solution for securing fasteners. I recommend avoiding them where they are inappropriate, but do use them when they are the best solution. Don't select fasteners out of habit, myth and lore, or because they happen to be available. When in doubt, use only what the manufacturer recommends.

Contests - The Highest Score Wins

When I was young I received a Scrabble game as a birthday present. It was a difficult game for a 13 year old since my vocabulary was limited. One of my sisters enjoyed playing since being 6 years older she knew many more words. She enjoyed winning even though the competition was weak.

Was I supposed to read the dictionary to learn more words? Dictionaries are big and after a few hours of flipping pages I judged that a poor strategy to bridge the gulf between our vocabularies. I needed a quick fix, not one that might take months or years of effort, and a boring one at that. 

[This is the point where I stretch the analogy to contesting, so please bear with me!]

What I lacked in raw facts I was able to make up in strategy. I reasoned that if I couldn't achieve a winning score with words all I had to do was impair her ability to make a high score. I became very good at boxing her in so that if I couldn't use a double or triple letter/word square neither could she. To her dismay I began winning games despite my limited vocabulary.

Winning is accomplished by scoring more points than your competitors, not by displays of intellectual prowess. Depending on the game there are always alternative paths to victory. The same is true of radiosport. But (as I alluded to in the warning above) we should never do it by impeding our contest competitors! Contesting is not Scrabble.

What's the equivalent to those obscure high-value words in radiosport? Contest scores are most often calculated from a combination of contacts and multipliers. For the purpose of my analogy, multipliers are the equivalent of high-value words -- working a multiplier can sometimes be the equivalent to the drudgery of working 10 stations. Finding and working multipliers is an important skill.

Multipliers are contest gold. They may be sections, counties, political districts, zones or countries. You can beat your competitors by logging fewer contacts if you can log more multipliers. Sometimes significantly fewer contacts. 

No matter your contesting objectives, working multipliers is always exciting. Therein lies a danger: if you pursue multipliers for the rush of excitement they bring, they could become your downfall. But only if you're truly out to win; otherwise there no harm in the practice.

Early in my contest career I had a terrible habit in DX contests of camping on a country multiplier and striving against the pile up to get it in my log. Valuable time was wasted. That was when I was still a "little pistol". I knew it was foolish yet I kept doing it. It was a difficult habit to break. Honestly, I'm actually not sure that I've broken the habit. It may just be that I've built a station so big that I can crack pile ups on the rare multipliers on the first call. 

But those are DX contests. I'm a keen DXer so my obsession was not too surprising. My attitude is quite different when the multipliers are not countries. I don't know that I've ever worked a clean sweep in ARRL Sweepstakes and I don't care. Others obsessively pursue a sweep. That's okay, if that's important to you. Just don't imagine that achieving a sweep makes you a great contester or a winning strategy. For that, compare your final score against those of your competitors, including those that missed a section or two. That decides who wins.

Other contests where a "sweep" of the multipliers is a popular objective are several of the state QSO parties (especially California and Florida), districts in WAG (Worked All Germany) and some other country-specific European contests. There are others of the same ilk.

Yet you never hear of anyone complaining that they've never completed a sweep of all 40 zones or all 340+ countries in CQ WW. The first is barely possible while the latter is effectively impossible. Propagation can be difficult and, more often, there is no activity (contest or not) from many countries.

The same impossibility applies to VHF where grid squares are the multipliers. Again, nobody talks about sweeps in these contests.

That's quite sensible. Why pursue a multiplier sweep when it is impossible or so improbable that it might as well be impossible. With effort it is possible in ARRL Sweepstakes, QSO parties and a number of other contests. 

Is it the possibility of a multiplier sweep that sparks the drive to achieve that objective? Many contesters ardently follow rovers and closely monitor spots (assisted classes) in the bigger QSO parties to ensure they don't miss any of the rare counties, which may be active for only a few minutes. You snooze, you lose. Many use assistance with the sole objective of a sweep.

Although not contests, you find an all or nothing objective in operating awards such as reaching the top of the DXCC Honor Roll or in the pursuit of the 6 meter FFMA. 

But in contests, the pursuit of multiplier sweeps has little to do with winning. Except in certain types of contests. Can you guess what distinguishes those contests from those where a multiplier sweep is no one's objective?

Those are the contests where activity is limited. It is easy to run out of stations to work in most QSO parties, in ARRL Sweepstakes, among others. When your rate slows to nothing, what can you do? You stop operating for a while or you hunt multipliers, if they're active and you can find them.

Rover schedules and highway roadmaps are studied, you camp on the rover's frequency waiting for them cross the country line, and eyes repeatedly glance at the multiplier window being populated by spots.

Many find tremendous enjoyment in the pursuit of multiplier sweeps. I do not, but who am I to tell them that their enthusiasm is misplaced. If there were many more stations to work they probably wouldn't be doing what they're doing. What's the harm?

In those cases, there is no harm. Yet I have to question the contests where that happens. It becomes less of a competition and more or a scavenger hunt. A curious game though not a terribly competitive one. There is no time for those games in a contest with lots of activity. Sure, you still hunt multipliers but you keep your aim solely on the score. Better to skip a mult or two if you can run up the score faster by running and SO2R.

I like entering many of the low activity contests, but not to pursue sweeps. It's good practice and fun. The time needed to build the score when the rate drops by waiting for new mults to appear is unappealing to me. I am never competitive in those contests, only operating when and if I feel like it.

When RAC (our national organization) recently added a new section for administrative reasons, some contesters reacted with alarm. If adopted as a multiplier in foreign sponsored contests like ARRL Sweepstakes, a multiplier sweep will become more difficult. So what? Do they also complain that P5 is hard to work in CQ WW? 

It doesn't impact a station's competitive position when a multiplier isn't activated during a contest since it has no effect on the results. The only impact is those whose objective is a sweep. It is of no consequence for contest competitors.

Don't lose perspective. If sweeps is you aim, go for it. But if your aim is to win or rank highly, focus on your score, not an arbitrary objective.

30 Meter Delta Loop

I have often lamented that I have no antennas for the WARC bands: 30, 17 and 12 meters. Making or buying antennas for these bands is easy enough, it's just that I primarily focus on the HF contest bands and I don't want to crowd the towers and create unwanted interactions. I have relied for years on antennas that can be matched with a rig ATU (or the wide range of a manually-tuned tube amp), and kept pushing off better performing antennas for those bands.

I can get away with it since many of my antennas are high. Height can compensate for poor efficiency and pattern. I do pretty well in the DX pile ups on those bands. Nevertheless it is a gap in my station. In the heat of summer and while waiting for the hay to be harvested I decided to undertake construction of a simple 30 meter antenna. 

Although it's simple, it is worth an article. The reason is that many of the mechanical and electrical issues I dealt with are commonly encountered by hams choosing, designing and building antennas. Hopefully this somewhat lengthy article will prove helpful to some readers. 

I had several objectives for the antenna's design and deployment:

• DX friendly: I operate the WARC bands solely to chase DX. That means low elevation angles.
• Omni-directional: Directionality requires rotation or electrical direction switching, which is far more investment than I want for a simple antenna that will not see heavy use.
• Interaction: My contest band antennas have priority. I won't tolerate interactions (which are almost always detrimental) from this antenna.
• Support: The main towers are in a hay field. I need the antenna to be entirely off the ground, including supports, so that tractors can freely drive beneath it.
• Simplicity: I have enough maintenance challenges that I do not want this new antenna to create a lot of unwanted work in the future.

My choice was a vertically polarized delta loop, fed ¼ of the side length up from a bottom corner. This is a common method to achieve vertical polarization in a delta loop. Elevation angle is low, it's omni-directional, doesn't interact with horizontal yagis, and it's simple.

In this model, the delta loop is 1 meter from tower centre and the bottom is 5 meters high -- as built, the antenna is 0.7 meters from tower centre and 6 meters high. That places the apex at about 15 meters, about 8 meters below the lower 5-element yagi of the 20 meter stack. There is one guy threading the delta loop since the lowest guy station is at ~30' (9 m). 

I modelled the tower as a long, thick vertical wire. As for shunt feeding the tower on 160 meters, I had to estimate the effective (electrical) height to approximate capacitance loading of the several yagis. I omitted the guys since they are broken into short non-resonant sections and likely have a small effect. Longer guy segments are located far from the tower and will not affect the delta loop even if there is near resonance at 10.1 MHz. I am more attentive to the effects for a directional antenna since the pattern nulls are easily perturbed.

The tower affects both pattern and resonance. It will still work if placed snug against the tower -- with suitable insulation since that's a high voltage node on the loop -- but will be detuned. If placed further outboard it can become difficult to install and maintain, and the pattern becomes more directional. I wrote about these parameters long long ago.

Rather than ask you to interpret those old words, here are a few notes to keep in mind:

• I used NEC5. Although accuracy is not critical for this antenna, the close spacing of the delta loop and tower is challenging for NEC2. There is no good way to align wire segments as NEC2 requires. Resonance dropped 500 kHz in NEC5 compared to NEC2. From my field measurements while building this antenna, NEC5 better reflects reality.
• The electrical height of the tower affects antenna resonance a small amount so it is not critical. Other factors dominate this antenna's behaviour.
• The closer the delta loop and tower the more omni-directional the pattern and the lower the resonant frequency. The first makes sense since with closer spacing the induced current will be closer in amplitude and phase.
• Why the strong coupling? Look at the current plot (above left). For a vertically polarized delta loop the voltage nodes (current nulls) are at the two points where the loop and tower are closest and therefore coupling greatest. This is a critical component of Moxon design, as one example. For a delta loop we need to be aware of the coupling if only because it affects antenna dimensions and demands good insulators at bottom centre and apex.

My initial estimate for the loop perimeter length was far off! I neglected to account for the above effects, opting for extra length and then trimming, and I was misled by my initial use of NEC2 within EZNEC. The initial test placed the resonance at 9.0 MHz or more than 10% long. Following up with NEC5 gave a better estimate. Trimming came later. The discussion about the SWR below was using NEC2, which caused several issues, as we'll see.

30 meters is only 50 kHz wide (0.5%) so it is easy to achieve a low SWR across the band, as the NEC2 model's SWR demonstrates. The matching network is a λ/4 transformer made from a 4.9 meter length of 75 Ω coax, included in the EZNEC model. The NEC2 unadjusted feed point impedance is about 115 Ω, which is typical for a full wave loop. The feed point is ¼ leg length (2.5 m) from a bottom corner. If you prefer a mix of vertical and horizontal radiation, a typical choice is to feed the antenna at a bottom corner. Expect a small impedance change, though not enough to justify a different matching network.

That's enough for now about the NEC2 model. Let's move onto construction before dealing with the model errors. Despite being a simple antenna there are several potential trouble points to be considered.

The bottom of the delta loop is made from aluminum tubing. This was done to meet the criterion of no ground anchors. I chose a couple of long tapered surplus yagi elements from my aluminum stock and spliced the inner 1" OD tubes with a 1.315" pipe. It's about 9.5 meters long -- the 3 sides add up to about 30 meters, or 1 wavelength). 

Surplus #12 insulated wire from a decades-old wire antenna was used for the two sides. The EZNEC wires include the insulation since the lower velocity factor shortens the required length, typically 2% (VF of 0.98). As is typically recommended for wire antennas, I cut the wires a little long. They can be trimmed to bring the antenna into resonance where you want.

The sides of the loop pull up the drooping long bottom tubing and provide tension to the structure. The tower bracket keeps the bottom in position and prevents it from rotating in the wind (picture and description further below). The ABS pipe insulates the bracket from the antenna. A good insulator is needed since the centre of the bottom side is at a voltage node.

A vertically-polarized full-wave loop doesn't have to be high to work well. As you take it higher there is more radiation at higher elevation angles and that is usually (but not always!) less than ideal for DXing. However, ground loss increases at lower heights. There's a tradeoff. 

I had to choose a height that minimized potential interaction with the 20 meter yagi up 23 meters while allowing clearance for farm machinery. My initial choice of 4.5 meters was increased to 6 meters to be certain of avoiding collisions. It is still well below the bottom 20 meter yagi.

The other interaction consideration is the cage gamma rod alongside the tower. The tower is shunt fed on 160 meters. There will likely be a tuning impact on 160 that I'll have to compensate for. Since the radials are removed for farming operations that can't be done yet.

I temporarily connected the delta loop to the 160 meter transmission line and made the required changes in my antenna selector software. By fall, when the 160 meter antenna is back in service, I'll add an auxiliary switch so that the antennas can share the transmission line. There is no foreseeable case where both antennas will be used at the same time.

I made brackets in my workshop for connecting the wire sides of the loop to the aluminum tubing bottom. Small strips of aluminum are held to the tube by hose clamps. There is a lip to keep the strips from slipping out. The wires are connected to the slanted upward end of the bracket by ¼" stainless bolt. Smaller bolts are strong enough but the smaller washers are insufficiently wide for wrapping #12 wire. The wire ends are looped and tinned for strength and to protect against corrosion, respectively.

The brackets can be slid along the tube for fine adjustment of antenna resonance without having to cut the wires. That feature came in useful.

The ¼λ transformer is made from RG59. It is found cheaply at local flea markets and is sufficient for the lower power permitted on 30 meters. It might handle a kilowatt but I don't intend to find out! The coax is coiled into a scramble wound CMC (common mode choke). It's less than ideal but good enough for a simple antenna like this one. Use a better choke if you prefer, but take into account its weight on the wire side of the loop.

When I modelled the antenna I added wires to simulate common mode on the outer side of the coax shield going down to the ground. To my surprise it had a deleterious impact on the pattern. Modelling the coax outer shield proved beneficial since even simple antennas can behave in ways you might not expect.

The RG59 solid centre conductor is fragile so I didn't want it swinging in the wind. Coiling the coax and binding it to the feed point insulator helps to avoid trouble. There is no wind induced flexing of either the open wire ends of the RG59 or the antenna wires. I added a short length of stranded and tinned wire to the centre conductor to further protect it should there be any unexpected movement. Weatherproofing of the open RG59 end was done after the picture was taken.

The LMR400 feed line is unsupported between the feed point and the tower. One advantage of LMR400 in this application is that it is lighter than many alternatives, included the heavier RG213. Their wind loads are equal and that may be a factor of coax choice if strong wind is a concern. RG58 might be a better choice for that case but, again, power handling might be an issue for bands other than 30 meters.

When the wire sides were draped over the tower guy station and connected to the bottom section, the bottom corners of the loop were slightly off the ground. This was my chance to do a "sanity" check. It may seem odd if you've never seen it done before, I connected the analyzer and swept the SWR over a wide range. 

Obviously the antenna is nowhere near functional in this state! However, this test will indicate whether the antenna is functional. There will be excess ground loss and significantly lowered resonance since it is sitting on the ground, and the apex is draped over a conductor (the guy station anchor). The SWR dip down to about 4 at 8 MHz was a satisfactory result. Had there been no dip around that frequency I would have checked all the connections to see if there was a mistake. I've done the same test with tri-band yagis propped up a few feet above ground.

Confident that the antenna was approximately correct, I weatherproofed the exposed conductors and capped the coax connector. Raising the delta loop for a proper test was delayed a few days while I attended to other matters during a bout of extreme heat (well, for us). Working outdoors was unpleasant.

The apex of the raised delta loop is a convenient distance below the long tube that supports the top of the 160 meter gamma rod. So that became the upper support. Rather than tying the dacron rope directly to the wire, I routed the wire over a large thimble I pulled from my junk box. The thimble avoids a sharp bend in the wire and makes it easy to level the loop by sliding the wire over it. Since I was working alone I did it by observing the antenna's shadow. 

Under tension the friction is high enough that the insulated wire is unlikely to shift. But it wouldn't be a bad idea to connect the wires on both sides of the thimble to limit motion. Don't pinch the wire since that can alter the tuning. Instead use a length of PVC or other plastic rod. Make it longer and the interior angle can be raised from 45° to the ideal 60°. The acute angle is due to wire sag. I can't increase wire tension any further since that pulls up the ends of the tube bottom side.

The support rope is looped over the gamma rod support tube several times. Tension and friction prevent the rope creeping along the tube. The rope is loosely tied to the tower to prevent it blowing in the wind. It is not a truss for the tube, as it may appear in the picture; the tube is strong enough on its own.

This is a view from the ground of the bottom side bracket. The hardware store utility angle is not strong enough for this application but it was handy and didn't require that I do any drilling. There is very little weight on the bracket since the apex support rope takes much of the strain. However, the wind load on a 10 meter long tapered tube is a danger. The ropes on either side of the ABS pipe provide lateral support.

If the antenna works well I'll replace the bracket with a stronger one. There is no rush. 

When I tested the antenna in its final configuration it resonated at 9 MHz. That's more than 10% low! After further tests and modelling using NEC5 (as discussed earlier) I lopped 1 meter off each of the two sides -- shortening the loop by 7%. That's less than 10% but it is better not to overshoot when trimming wires. With several factors that influence resonance there is more than one way to reaching the desired endpoint.

Trimming raised the resonant frequency to 9.7 MHz, which is indeed about 7%. For the final adjustment I slid the wire brackets at the ends of the bottom tubes inward by 65 cm. That put the SWR curve where I wanted it. 

The SWR is unfortunately difficult to read in the adjacent picture. The centre of the display is 10.1 MHz. The SWR is about 1.8 mid-band. I took the measurement with a 50' roll of LMR400 that was looped over my shoulder. The open run to the feed point drooped more than was ideal. 

The SWR improved when the cable was properly dressed and routed down the tower face. However it was still no better than 1.5. When I returned to EZNEC I discovered the reason. I had neglected to rerun the SWR plot using NEC5. NEC2 did not correctly calculate the impedance due to close coupling to the tower.

The tight coupling lowered the feed point impedance to between 75 and 80 Ω. That is much lower than the 115 Ω calculated by NEC2. The RG59 ¼λ transformer is doing nothing at all since its nominal impedance is the same as the antenna. I could do away with it but it's still handy as a common mode choke.

The insects and heat were insane so I decided that this was close enough. The rig put power into the antenna just fine without the ATU.

That's the completed antenna. There is enough tension in the support rope to pull up the ends of the bottom side a small amount. That adds stability to the antenna. Also notice that the coax is routed so that it comes off the side at close to a right angle to reduce coupling. It can't be entirely eliminated since the coax must traverse the interior of the loop when fed for vertical polarization. The 3 sides are not quite equal but close enough not to noticably impact performance.

That evening I put the antenna on the air. It was easy to be heard by the DX stations I called on CW. However there weren't many DX stations on CW. I monitored FT8 and the antenna at least heard well, copying many stations in Asia. But I didn't transmit.

I will have to move the transmission line back to the 160 meter antenna since I need it for a couple of upcoming contests, despite the lack of radials. I hope to have the transmission line remotely switched for both antennas by September when I'll install the 160 meter radials in preparation for winter.

Summer Happens

The blog has been quiet for a few weeks. I've been here and getting things done but, well, summer. 

We've had a lot of unusually hot weather which makes it difficult to work outside. Although most of the hay has been harvested, making room for antenna work to resume, there are other considerations. I enjoy non-radio activities in the warm weather, and when I get on the air it is usually to check for 6 meter sporadic E.

My primary antenna season is the fall when it turns cool and the bugs diminish. Which is not to say that nothing is happening at the moment, just nothing worth its own blog entry. I have been up the towers numerous times in July and I'm not done. Mostly I am investigating problems, making minor fixes and planning for upcoming antenna work. 

Working alongside the hay, even after harvest, is uncomfortable due to the heat, humidity and ferociousness of the insects. They are attacking anything on 2 or 4 legs to prepare for winter. However, once you are 20' above ground they miraculously vanish. But most of the work is done on the ground and that is uncomfortable and occasionally painful. I won't ask friends to endure that when they volunteer as ground crew. There will be enough time later in the season.

To break the silence I decided to describe the projects I've been working on. With a big station there is always work going on, even if each job isn't worthy of its own article.

30 meters

I have no antennas for the WARC bands (30, 17, 12 meters). After 9 years at this QTH that is about to change. A 30 meter omni-directional antenna that was simple to build and won't interact with contest band antennas. Expect an article shortly about this antenna. You can see enough in the picture above to guess what it is.

Rotators

I can sympathize with the many contesters and non-contesters that have opted to forgo the difficulties of rotatable yagis. Since the tradeoff, for my station objectives, is more towers and antennas pointed in various direction, I put up with rotators and their inevitable failures. 

The direction indicator for one my prop pitch motors is misbehaving. The fault took time to recognize and isolate since it occurred at the same time I completed my new controller. It should not be difficult to fix now that I've isolated the fault location. 

The chain drive on the other prop pitch motor needs attention since the chain has more slack than I'd like. It's an alignment problem that has been there since it was installed in 2017. The momentum of a 3-element 40 meter yagi rocking back and forth puts unwanted stress on the system. I will attempt a solution this year.

40 meter Moxon

Regular readers may have wondered why there was no promised article on the antenna's performance. The reason is that there are internal wiring errors that were undetected in the rush to get it out of the hay field this spring. The repairs are simple but must be done on the ground. It is likely that we can lower it, do the repair and raise it again the same day. I am waiting for the heat and bugs to abate and for the last of the hay to be harvested.

XM240

It is sitting on the ground and awaiting judgment. That is, to sell it or put it back on a tower. If it goes up it'll probably be fixed south as a multiplier antenna. The TH6 fixed south serves the same purpose on the high bands. You can never have enough antennas! Should I decide to sell it, there is a buyer standing by.

IARU contest

The station was active in this 24-hour contest in mid-July, but not operated by me. Vlad VE3TM attempted to surpass his CW low power score from last year. Although conditions didn't cooperate he appeared to have a good time. More guest operations are in discussion for future contests.

Beverages

Problems have been cropping up over the summer. Since the antennas are off in the bush they have been effectively inaccessible, and will remain so until October. They'll be repaired in time for major fall contests such as CQ WW. I am thinking more seriously about an alternative low band receive antenna system that is less vulnerable to the depredations of nature. Beverages are great antennas but the frequent maintenance and repair is becoming a burden.

Amplifiers

The Acom 1500 is still out of service. I've been trying to diagnose and repair the amp without success. I suspect damage somewhere in the measurement and protection circuits. Unless I resolve this shortly I'll have to ship it for repair. That will not be cheap since there is no commercial Acom service centre in Canada. I have two other amps so this issue is not impacting my ability to operate.

Portable power

A couple of years ago I purchased a portable power station for power outage emergencies. These events are not common but when they occur they can last for many hours. For example, in stormy weather it is vital to run the sump pump. I have since found it handy for many household chores and for antenna work. Rather than having to buy a set of battery powered tools I can carry the power station into the field, far from power outlets, and use my existing corded tools. It came in handy this week for trimming and soldering antenna wires.

Everything else

As sporadic E propagation fades on 6 meters and poor prospects for a high MUF this fall my thoughts are reluctantly returning to HF earlier in the season than expected. Since I am now less likely to miss openings, there is more time to go cycling, follow the Tour de France and otherwise enjoy the great outdoors. 

I am also reflecting on the future. I am human and age brings its challenges. While I remain physically strong there are signs of creeping old age. Two cataract surgeries this spring and other small issues feature among those. I am becoming accustomed to using more lighting and magnification to do close work. Tower work continues to be a non-issue, for which I am thankful.

I hope for many more years of working of sustaining and growing the station, and writing for the blog. Never stop learning and striving for personal improvement.