Tuesday, April 24, 2018


The killing field. The large tree on the
ground is the one that did the deed. The
other leaning deadwood is now cleared.
There's been a lack of articles recently for a variety of reasons. We had a string of springtime snow and ice storms accompanied by two days of high winds (up to 90 kph). Once that was out of the way I had to deal with an impacted wisdom tooth. This brought all antenna work to a halt for nearly two weeks.

Once I could get outside and do stuff again in the late-to-arrive mild spring weather there were many non-ham jobs that took priority. One of these tasks was to clear away fallen trees and branches due to those storms. Even so I have been able to do some antenna work, in particular making progress on the 80 meter vertical yagi. I'll have more to say on that in about a week.

What I thought would be one of the more mundane tasks was to inspect the northeast Beverage that goes through some heavy bush along its 175 meter length, with the far end at the edge of the swamp (bog). By mid-May this area will be effectively off limits since the growing vegetation will host some nasty wildlife. By this I mean that the bush and hay fields become tick heaven until at least mid-summer.

I had a suspicion this wouldn't be a normal inspection since the Beverage has not been performing well lately. When I approached the feed point my fears were confirmed. The aluminum wire was slack, evidence of a break somewhere. A month earlier all had been well. I waded through the bush along the antenna line looking for the problem.

Wire hanger bent when the tree fell on the Beverage
Approaching the termination the land slopes gently downward into the swamp. With the frost not out of the ground in sheltered areas run off pools on the surface. The ground is very squishy. The problem was discovered just 15 meters shy of the termination resistor.

Presumably during the storms a lot of the dead and dying trees met their fate. Trees in the boggy ground are prey to disease and rot. Many of the softwoods are skinny things with sparse leaves, unable to fare better in the saturated soil. Even so they pack a punch when they come down. It has happened before though without ill effect. Aluminum fence wire is surprisingly strong. However it is not invulnerable.

I counted five of these benighted trees in the space of less than 10 meters that had fallen onto the Beverage wire. One of them was large enough to sever it. Surprisingly a couple of the broken trees were still leaning against the wire which was still under some tension because the big tree was lying on top of it.

Manual splice: ugly but
it works, for now
A severed terminated Beverage becomes an unterminated Beverage. This is still a reasonably good receiving antenna except that it is bidirectional, only rejecting signals off the sides. A bidirectional Beverage has the advantage of covering two directions at once but with the serious disadvantage of poorer performance in the one direction you are most interested in.

The dead trees were pushed aside to rot in peace on the wet ground. After determining that the termination box containing the resistor and the ground rod connection were undamaged I retrieved the broken ends of the wire and manually spliced the break by wrapping 3" of the wires together. It held when I pulled on the wires to test the splice. Although this is not the proper way to splice aluminum wire it is a quick and easy way to temporarily put the antenna back in service.

I was not done since the slack had to be taken out the Beverage wire. All soft drawn wires will stretch a surprisingly large amount when put under high tension. It should be obvious that a wire that has been pushed beyond its breaking strength has also been pushed beyond its yield strength, which is typically ~70% of breaking strength. The 175 meter wire stretched ~60 cm (2').

Since I had only about half that much rope remaining at the termination I returned to the feed point, along the way lifting the wire off the foliage that trapped it while it lay slack. I removed the rest of the slack at the feed point and was pleased to find that my improvised splice held. Again I followed the wire to the termination and then back to the feed point to pull the wire free from twigs it snagged as it was lifted to its original height. Yes, this is a lot of work! Having an antenna farm is not for the lazy.

When night fell I was pleased to discover that the antenna was back to its usual awesomeness. Hopefully it'll survive the summer. In the autumn I may replace this antenna with a bidirectional Beverage although I am still loathe to tamper with an antenna that performs so well to Europe, which is the most productive contesting path.

This tree was too large to remove without assistance. Instead I
defanged the threat by cutting the branches which are long
enough to strike the Beverage wire when the rot progresses
to the point that the tree falls the rest of the way down.
The next day I went back into the bush with a saw and cleared away several dead and dying trees within reach of the Beverage. I want to avoid a repeat. Luckily it is only this area near the swamp that has sick and risky. Elsewhere they're healthy and strong and not too tall or are evergreens that do not have large overhanging branches.

Having lots of trees available as supports is nice provided you account for the risks. Everyone I know who runs Beverages through bush periodically clears deadwood, and yet still suffer breaks from time to time. This is my fate as well. Beverage maintenance will only become more onerous when I put up more of them.

Is it worth the trouble? In my experience: yes! Just keep these things in mind:
  • It's not a matter of if but when. Have a plan and material on hand to quickly and effectively repair or replace Beverage wires.
  • Splicing aluminum wire is difficult and there is likely no mains power nearby. Beverages made from coax that are spliced with connectors cannot take tension so you'll have to use messenger wires or replace the coax.
  • Inspect the full length of Beverages twice each year. Once in the spring after winter has done its worst and again in fall before the contest and low band season begins. Remove suspect trees and deadwood that can threaten the Beverage when they come down.
  • Be safe! Cutting down trees is dangerous work. It is even worse with deadwood since you will get little warning when a rotten limb or trunk you are sawing snaps. Trees will kick out, twist, break, pivot on obstacles and otherwise behave unpredictably when they are cut, chopped, pulled or pushed. They can be far heavier than you expect since deadwood is often waterlogged. Do not overestimate your ability to outmanoeuver a falling tree!
Get the help of a friend or professional is you are uncertain how to proceed. Don't improvise! As you would for tower work acquire and learn to use the proper tools. Beverage antennas are wonderful things but are not worth the risk of serious injury.

Deadwood cast aside to peacefully decompose on the wet boggy ground

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