Tuesday, March 21, 2017

Perils of Expediency

As I wrote my series of articles on tower construction and antenna raising in the midst of a Canadian winter I downplayed the difficulties. Trust me, it is no fun at all standing atop a tower when the temperature is -5° C and the north wind is blowing while I am propping 20 kg of antenna on my shoulder and threading nuts on bolts to (hopefully) finally get a yagi securely attached. Of course I have to do this with gloves off.

I am thus reminded of just how driven hams can be in the pursuit of what is essentially just a hobby that we would undertake these challenges. It is little wonder that those around us sometimes think we're just a little bit crazy.

Considering the conditions it should be no surprise that I took shortcuts. I deliberately did sub par work to minimize exposure to the winter weather and the associated hazards. Although I am not proud of that I did what I felt needed to be done to get me on the air this winter. Expediency has its price, a price that I am now paying. My hope that all would survive until spring did not come true.

Here is my list of things that went wrong. Some have been briefly mentioned in preceding articles.
  • What I had at first thought was an inexplicable interaction between the XM240 40 meter yagi with the 80 meter inverted vee turned out instead to be an intermittent connection in the coax rotation loop. I had tested the coax on the ground and I taped the coax such that there were no connectors within the loop. It needs to be fixed to keep the yagi working at all times.
  • The rotator wiring has suffered two failures, both caused by reusing the only cable I had on hand that had connectors on it was long enough. The cable has several splices, the wire ends are frayed and the connectors are difficult to waterproof. One of the splices sagged onto the ground just before a heavy snowfall and subsequent thaw. This caused a few days of unreliable direction indication. I dried and cleaned the splice and made sure it was properly supported above ground. Then the rotator failed entirely due to a broken connection. Jiggling the cable and re-securing the connector at the rotator was only a temporary solution. Now I have to remove the rotator from underneath the mast to do a proper repair.
  • The mast and tower are overloaded for my wind zone. I did this to have yagis on 40 through 10 meters through the winter. For the second time the mast has slipped in the rotator clamp in high winds.
  • The galvanized muffler clamps securing the XM240 to the mast are not up to the task. These fasteners are not designed to withstand axial loads. The formed sheet metal saddles can bend under axial load. The saddles ought to be solid and have a large gripping surface. I already knew this when I chose what was locally available: inexpensive and easily acquired under a tight schedule (expediency).
  • The Trylon is almost but not quite vertical. Fighting with the gin pole and splice bolts has in a few resulted in a couple of instances of an improperly seated section. Although not a serious problem and only noticed when looked at closely -- it's about 1° out of true from about 25' above ground -- it irritates me.
  • Running cables on the ground risks damage with the amount of house renovation and construction that has continued through the winter and now into early spring. There has been one instance when a contractor spread out a bunch of tarps to dry over the cables, which means they walked over them, not noticing them due to the light snow cover. Luckily there was no damage.
  • The wire of the Beverage antenna sags in a few places low enough to reach up and touch. There is risk of wildlife damage, especially bucks being chased by coyotes (yes, this sort of thing really happens on my property). Since the antenna looks like a keeper I'll have to redo the support system to keep it high enough to prevent injury and damage.
Despite this litany of woes the station has performed very well over the past few months.


The immediate problems that needed fixing were the coax to the XM240 and the rotator wiring. All the other problems can wait for spring.

It took a couple of trips up the tower once the weather cooperated. The first climb was to assess the problems better than I could from the ground and to haul up the things I'd need to complete the job. These items included a power cord for soldering, clamps to support the mast and antennas when the rotator was temporary removed and cords from yagi to tower to limit mast rotation during the repair period.

I slightly loosened the bolts securing the mast to the rotator and the rotator to the tower plate. This was done to ensure there would be no delays when the work was to be done. A new method of raising the mast and antennas (200 lb) was experimented with and discarded. Better to get that dealt with beforehand rather than wasting time later.

Before descending I fiddled with the rotator wiring and connector, purely out of curiosity to see if it would work again (it did). Locating the source of XM240 misbehaviour was quickly determined to be an ancient nickel-plated PL259 UHF connector on the 40 meter run of RG213.

The braid had broken off the solder to the connector body. I had mistakenly secured the coax to the tower below that connector instead of above. The connection experienced rotation stress, especially severe in cold weather when the coax is stiff. Never place a connector within a rotation loop. This is the price of sloppy work when the north wind is howling.

The next day a ham friend arrived to serve as ground crew. The forecast was promising to effect repairs, including soldering a new connector onto the main run of rotator cable. Unfortunately the weather stayed cool and turned windy making soldering too difficult; I had a small soldering torch, but that can't be used on a multi-pin connector since it'll melt the plastic body. Nevertheless I did get much of the work done.

I used a car scissors jack under the XM240 boom-to-mast clamp plate to raise the mast about 1 cm, which is enough to allow the rotator to be removed. Clamps at both bearings served as insurance in case the jack slipped. Of the many methods to lift 200 lb of mast and antennas off a rotator using a car jack is simple and fast but has the serious disadvantages of being unstable in a wind and placing undue stress on the antenna clamp. It was desirable in this instance since it was fast and easy.

With the rotator sideways on the tower plate I scraped off the old silicone sealant and then removed and discarded the wiring harness. The new one I had prepared was quickly attached and the rotator reinstalled. I then removed the jack but left the mast clamps in place in case the wiring was faulty and the job needed to be redone. Before retiring for the day I secured the XM240 coax from motion during rotation, thus protecting the broken connector.

I planned to return to the job later when the weather improved. Not only did it not improve the forecast was for moderately high winds. The next day I cut down the full length of rotator cable, brought the end indoors and soldered on the new connector there. Then back up the tower to reinstall the cable. In the end it was easier and faster this way. I then removed the mast clamps so that the full weight of the antenna systems rested on the Tailtwister once again. I left them on the mast, just in case!

Since the XM240 worked fine as is I decided to abandon repair of the coax connector for another time. The wind speed was rapidly climbing and it was time to finish up and descend. Fortunately the new wire harness and connectors worked placing the rotator back in service. If nothing else I am now prepared for CQ WPX SSB this weekend should I decide to enter: it is not a favourite contest of mine.

Spring follow-up

Since my weather associated fiasco in attempting to plant the 150' tower last fall my 2017 plans have been adjusted in accord with that event. We are now waiting for the ground to thaw and dry out enough to allow the foundation work to be completed. I predict that will happen in early to mid May. With luck the tower should be up by the end of June. I'll write up the full woe-filled story once the foundation for the tower is complete.

Until then I have the one tower for my antennas. I will need to make some compromises on operating since I need to raise the refurbished 6 meter yagi for sporadic E season starting in May. I will likely have to take down the XM240 for that and put it aside at least until the new tower is up. So I will likely have reduced capability for CQ WPX CW at the end of May. Perhaps I'll temporarily put up one of my old 40 meter inverted vees.

I can then leave the Explorer 14 where it is for a while longer, stacked on the mast with the A50-6. July will be when the major antenna work can begin.


Expediency comes at a price and I paid for it this winter. I'd do it again. The success I've had in contests and DX chasing for the past 12 weeks was well worth it to me.

Should you ever do anything similar be honest with yourself. Put the risks up front, assess them and prepare accordingly. Do not fool yourself. That is a sure path to disaster. Avoid expedient choices except in a pinch. Even then don't do it unless you are comfortable with the risks.

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