Keeping Busy During the Pandemic

In addition to no availability of helpers during the pandemic lock down the weather has been anything but springlike. The temperature has been very cold, so cold that it's been snowing. In May. We experienced high daily temperatures that are below the normal high for this time of year. The combination of cold, high winds and snow is delaying many antenna projects.

Recent visitor walking past the towers

Even so quite a lot has been accomplished on the ground, some of which I've related in recent articles. While not the most interesting of items to relate, in this article I'll describe the many projects that have kept me busy. During these challenging times there is still much that can be done.

Antenna decommissioning

From the 150' (43 m) tower I completely removed the 80 meter inverted vee and my seasonal 160 meter antenna. As I've previously reported the 80 meter inverted vee has proved less useful than expected. The 160 meter antenna radials are in the way of farm equipment for haying season and must be removed for a few months.

I have no firm plan to put the 80 meter inverted vee back up except possibly at a lower height where it was originally installed. I also have to give thought to 30 meters since this was the only antenna that worked well on that band. When the 160 meter antenna goes back up in the fall I have a plan to improve its effectiveness with regard to efficiency and directivity. More on that later in the year.

160 meters on the 80 meter vertical yagi

When I last mentioned the addition of 160 meters to the 80 meter array the matching network was temporarily attached. The shunt capacitor has been moved inside the weatherproof box and the match has been improved. To do this the values of the shunt capacitor and series coil were adjusted.

The 2350 pf capacitance calculated with TLW is very close. The addition of 4 × 100 pf 1kV capacitors to the 2000 pf mica transmitting capacitor brought the SWR very close to 1. Coil turns were squeezed and spread to put the SWR minimum at 1830 kHz and then taped to the form to prevent movement. Due to its large size the coil remains exposed to the weather and that may be a problem.

It isn't perfect but it gives me year round access to 160 meters. There is activity through the summer months though far less than the winter. I mainly expect to use it in the few contests I operate in the warmest time of the year.

80 meter yagi

The 80 meter yagi itself requires repair. The galvanic corrosion noted previously was repaired by soldering tinned lugs to the wires that attach to the galvanized tower struts. This should be sufficient for years of service.

The northwest/southeast pair of directions is not working properly and the problem needs to be diagnosed. There was a broken control cable I knew about but that repair didn't solve the problem. There is no rush since the low bands are not a priority during the summer and these are the least used directions. Perhaps I'll look at it during the summer if I'm brave enough to hazard the ticks! I use a ground sheet to reduce the risk.

Trench warfare

Another consequence of the pandemic is the difficulty and expense of renting equipment. The fellow I usually rent from appears to be shut down for now and in any case he no longer has the trencher I used in the past. This is the trench to my most recent 140' tower. During the winter I had two runs of Heliax on the surface for the recently raised bottom yagis of my 20 and 15 meter stacks.

With the arrival of haying season I had to do something and fast. So I picked up a shovel and pick axe and went at it. Manual digging of a 170' (50 m) trench about 20 cm to 30 cm deep and wide enough to accommodate several runs of LDF5 and rotator/control cable is not a lot of fun. But as with contest operating and BIC (butt in chair) being methodical and persistent with SIH (shovel in hand) the job does not take too long.

The trench is shallower towards the far end and hugs the stone wall to avoid the roots of the beech trees lining the inside of the wall. The roots of the (currently) small spruce tree go deep rather than shallow and were no impediment.

Cables are bundled with those from the other big tower at the far end of the trench and follow the same overhead run to the switching system at the base of the 70' tower near the house. Total distance is ~230' (70 m).

The pictures provide perspective on the scope of the challenge. This is one time that ugly cold weather is advantageous. You don't overheat in the springtime sun and the black flies and ticks won't come out to play. You need only prepare to get wet and dirty. Overexertion is not recommended so I did it in stretches of no more than 1 hour at a time. The first day I broke the sod and set it aside. The next day I expanded the trench to the required depth and width.

Industrial electrical suppliers are open for pickup orders so I ordered the cable I needed and within a week the trench was ready for covering. That went faster than the digging. I put the Heliax at the bottom and the control cable on top, maintaining enough pressure to keep all of it flat on the bottom as I back filled the trench. The field is now ready for haying.

Tower maintenance

All the towers required maintenance and their annual inspection. Tasks including the antenna removal noted above. Nothing too serious was amiss though some things require repair.

On the Trylon (21 m) tower the only important task was to aim the yagis. The Tailtwister mast clamp is not the greatest and wind storm action on the 40 meter yagi occasionally give the mast a turn. This time the high wind (90 to 100 kph) moved the yagis out of alignment by 20° in late winter. The XM240 beam width is so broad that it didn't matter much however with the arrival of sporadic E season correct aiming of the 6 meter yagi is better than having to constantly remember the azimuth correction.

On the new 140' (40 m) tower the mast bearings developed surface rust despite being painted before installation last fall. I will remove the bearings and paint them properly with several coats. That's easier than painting them on the tower. This is only possible because the mast hasn't yet been installed. Although the double sealed bearings are silky smooth rapid rusting could become a problem as the years pass. While up there I completed the rigging to tune the upper set of yagis for the 15 and 20 meter stacks.

The TH7 on the 150' (43 m) tower was misaligned by the same amount as the XM240 and 6 meter yagis during the same wind storm. The direction pot was easily aligned at the control unit but an inspection was warranted. The saddle clamps were less tight than they should be. The antenna was turned and the bolts torqued.

Unfortunately the turnbuckle screws on the boom truss support were bent when the wind hit because the mast side of the turnbuckle screws are bolted to the mast clamp rather than freely pivoting in open eyelets. I was easier to do at the time with the material on hand so I took the risk. The turnbuckles are inexpensive and the TH7 is slated to come down later this year so I decided to leave it alone. It'll certainly last the summer.

Tuning the upper 15 meter yagi

The upper yagi of the 15 meter stack has been sitting out in the hay field over the winter. There was no rush to get it tuned and prepared for raising since I could not be ready until spring and better weather. The mast has yet to be raised and the bracket to be fabricated. In the hope that I can get that done before the hay grow too high I proceeded to tune the yagi.

This went far quicker than the first time. All the gamma match dimensions were recorded and replicated on the upper yagi. It is better to keep good records than to redo the work! Element length adjustments were done on both yagis at the same time so that their performance is as identical as possible.

It took only one tweak to achieve the excellent SWR curve shown. The yagi is too low for proper tuning. My intent was to check that the tuning was about what it should be and the mechanical work on the gamma match. It is back on the ground for remedial work on the gamma match before it is readied for final adjustment. The boom is stronger and heavier than for its lower twin since it will be rotatable and up almost 150' (46 m).

Due to the lock down the yagi likely won't be raised until August. It will be placed out of the way for the interim. The upper 20 meter yagi will not be assembled and tuned until just before it is raised in late summer. It is too large and heavy to be stored except in pieces.

Operating

It's a funny thing that despite staying close to home during the pandemic lock down my enthusiasm for operating has been lower than usual. From what I am hearing from others this is quite common. I will not force myself to operate since that would make it a chore rather than the pleasure it ought to be. The absence of DXpeditions and major contests doesn't help.

I have not been entirely inactive although I've done more listening than operating. Low solar flux has not stopped the polar path summer openings as 24 hour daylight returns to the high north. UA0, BY, JA and more southerly east Asia stations are heard on 20 meters almost every night.

On 160 meters there are morning openings to VK, ZL, JA and other distant locales. For a few minutes before and after sunrise (which is very early in the morning) stations come through with good signals. Unfortunately almost all the activity I've heard has been FT8 and not the CW I prefer. Since I am not an early riser I rarely catch these openings.

If nothing else it is an opportunity to experiment with the new Beverages and switching system. The great circle route to west Australia, which is near our antipode, is very different than east Australia and New Zealand. ZL is best on the southwest Beverage while VK5 and VK6 are off to the side on that antenna and are only heard on the north Beverage (VK5 is northwest and VK6 is north-northwest). The east-west reversible Beverage planned for next winter is needed.

With the 160 meter antenna removed the port on the antenna switch was reassigned to the 6 meter yagi. The end of 160 meter season is the start of sporadic E season VHF. I have already heard my first European and EA8 stations and worked stations in South America, Caribbean and Central America.

No new countries have yet been worked although a couple were copied. My hopes are high for the season which peak at the solstice in late June.

Snowbirds

The Snowbirds are the military aerial acrobatics squadron of the RCAF. Their home is at an air base about 150 km to the west in FN14. With the arrival of spring they have begun a series of countrywide tours as part of the government's plan to keep public morale up during the pandemic. Although my remote rural QTH is not on the schedule I am on the flight path to between their base and Ottawa and Montreal. I have seen them in the vicinity once or twice before.

Several days ago while I was down on my knees in the muck laying cables in the trench I heard the unmistakable roar of many engines approaching from the western horizon. Guessing what it was I stood up and pulled out my phone. Seconds later they made their appearance, flying low and fast and in formation headed east.

Realizing the rare opportunity I noted their flight path and ran back about 20 meters in my mud-caked work boots. I took several shots in quick succession and picked the best for display. I sent it around to a bunch of local hams and our contest club and it was well received. I'll end this article with that shot. Enjoy!