Fighting Flora and Fauna

This is not the first time I've written about my troubles with wildlife. While a rural QTH is great for antenna farms, the majority of animals are not accustomed to seeing or dealing with humans. Unlike they behaviour changes they exhibit in and near urban areas, they proceed as if in the wild. 

They come close and satisfy their curiosity by chewing or walking on cables, dig in the loose soil of recent excavations and make their homes in shelters built for antenna and cable switches and junctions, and inside tubes and pipes. Deer and their predators follow the trails I make through the foliage and snow. The predators are intelligent enough to respect humans, and their firearms, and keep their distance.

Dealing with animals, vegetation and insects is an unavoidable part of regular station maintenance. Sometimes it is damage I must prevent or repair, and other times nature must be tackled in pursuit of my antenna farm projects. Read on for my latest adventures.

Many insects like dark enclosed spaces in which to build their nests and to store food and eggs over the winter. To their delight, all of my outdoors enclosures for matching networks, switching and cable junctions have weep holes to allow moisture (rain or condensation) to exit. It seems that no matter how small I make the holes there is an insect that is smaller yet. I can't make the holes too small or the surface tension of water will prevent drainage.

Even so, when I built the Beverage antenna remote switch early in 2020 (see article for pics) I made the weep holes smaller than usual and the hole for the Cat5 control cable a snug fit. In early summer the switch exhibited intermittent short behaviour (excess current to the relay coils). A few weeks later when the hay was harvested and I could safely access the switch.

As I slid the cover off after removing the screws an enormous number of ants came scurrying out. They crawled around the enclosure, over my hands and up my arms, with most jumping off when they realized they were on an animal (me). In the 30 seconds or so that it took me to pull my phone out and take a picture only about half the ants were left inside.

You can see the cocoons under the ant mass. These had to be scraped off after the the ants were cleaned out. The funny thing is that the ants were not responsible for the switch failure. After bench testing in my workshop the likely culprit is a secondary lightning strike. Long Beverage wires are notorious for building up large induced voltages from nearby strikes, and in this case the integrated suppression diodes in the relays had failed. 

Unfortunately, as I discovered in a similar case, the diodes fail to a low resistance value (not a complete short) when their PIV rating is exceeded. I was further irritated that the specs for these Littlefuse reed relays do not state the PIV rating of the suppressor diodes. I didn't notice that when I selected them. For the interim I have more of these in my stock so I will be installing them shortly, in time for the fall 160 meter season. I would like to replace them with relays that use my choice of suppressor diodes.

Despite the diagnosis the ants are not innocent. They brought a lot of moisture into the small enclosure that left its mark. Notice that all the bare copper wires are heavily corroded (green). Tinned wire and hardware is unaffected. When I rebuild the switch the bare copper will be replaced by tinned wire. Wire that than cannot be easily replaced (e.g. transformer windings) will be coated to inhibit corrosion.

It is interesting that one of the two styles of coax jacks corroded (on the left) and the other did not. Application of dielectric grease to the threads should inhibit further deterioration.

The ants were a surprise since it's earwigs I typically have to deal with. Earwigs will climb at least several feet to find a nice comfortable hole to lay their eggs in late summer. At last count there are 6 enclosures with earwig infestations (including every one in the 80 meter vertical yagi). I am not yet able to reach the Beverage antennas which each have two enclosures (head end and reflection transformer) to be inspected.

The picture shows the 80 meter yagi switch box with the largest earwig infestation. It is the one at the base of the southwest parasitic element. All the covers were removed and the units left open for a few days until the eggs dried and could be cleaned out. Try it when they're fresh and you will only smear the black goo everywhere. 

A bit of rainwater while they're uncovered won't damage the relays and coil. Neither will a water rinse. Sealed relays can put up with a lot of environmental abuse.

Before winter I plan to deer-proof the cables and support ropes in the 80 meter yagi. They do like to chew things, much to my surprise. In my station they are far worse than rodents. Squirrels, mice and their kin have molested none of the on-ground cables. Sometimes a chipmunk will dig a home along a trench line but they have not damaged anything. Perhaps they favour recently disturbed soil.

In the picture above you may be wondering what the problem might be. It is an after picture, once the problem was resolved. When I put up my first big tower in 2017 the ideal location for one of the guy anchors was behind a short spruce tree. It was not really in the way so I ignored it. Little trees grow into big trees and that's when the trouble begins. 

First it gobbled up the lowest guy. I trimmed branches to avoid contact with the guy. The tree continued to grow and soon gobbled up the second guy and was well on its way to the third. I like trees so I avoid cutting them down when possible, especially an attractive tree in a pleasant setting like this one. 

My patience was exhausted when climbing vines that infest trees grew over the guys. Vegetation in contact with steel, including galvanized steel, promotes rust. With the help of a friend the tree was dispatched and roots cut out below ground. They guys are now free and ground levelled where the tree once stood.

There is a ham I know (call withheld to protect the guilty party) who installed a guy anchor near a seedling many years ago. The tree grew and grew until the anchor and equalizer plate were embedded in the trunk of the now large tree. Neither the tree nor the anchor seemed to suffer from the experience, or at least not yet. I would have loved to take a picture but did not to avoid offending the ham in question. It would have made a great picture, and an instructive one.

Speaking of anchors and trees, there is one last item that is a little different. In this case the tree in question is very much wanted.

A few years ago I opened a path in the bush at the east end of the hay field to use a tree as an anchor for tramming yagis up and down the 150' tower. This worked well. I want to do the same this fall when I decommission the TH7 and bring down the experimental 40 meter yagi element. 

If the latter passes inspection for its mechanical soundness it will become the driven element of a 3-element 40 meter yagi. That project is proceeding and if all goes well it will be built and raised to 150' later this fall. The yagi will weight close to 300 lb (135 kg) and will require a tram line that is equal to the challenge.

There is a large and healthy tree deeper in the bush that appears to be ideal. Equally important is that it is directly opposite the guy anchor discussed earlier. The guy anchor, which has a spare eyelet for this purpose, will hold a back stay cable to the mast to balance the large force of the tram line tension and the yagi's weight.

Clearing of the bush to access the tree and make a path for the skyward pointing tram line is ongoing. The above picture shows the current progress. The tree itself is hidden in shade at the centre of the frame. I'll have more to say about it when it is ready. As a trial run the tree will be used as an anchor to lower the TH7 and 40 meter yagi.

I'll close on a more amusing note. Wild turkeys are common in the area. They roam the lawns and harvested fields almost daily this time of year. They step around guys and over radials and, so far, have done no damage. I leave them alone.

The big birds are shy and run (or fly) when they see me. This one was taken through the window. One day earlier this year there were more than 20 of them in the driveway.