I was watching the tower crew measure the guy tensions on this tower the other day:
AM tower
The preferred method is to use a pulling force to move the guy wire slightly off of the turnbuckle or hairpin bolt then measure that force. Hydraulic rams with a pressure gauge are used more often then not.
hydraulic ram, showing 7,000 lbs pulling force
These guy wires are called “Bridge Strand,” the bottom wire is is 7/8 and the top is 1 1/8 inches. Normally, these are tensioned to around 5 – 10% of their breaking strength at 60 degrees F. In this case, it was slightly colder so the tensions are a little bit higher. If it would have been warmer, then they would be a few percentage points lower.
A couple of videos for your viewing enjoyment:
Lower guy tension 7,400 lbs, Upper guy wire tension 10,500 lbs. Both are well within their ranges.
Warm, unmanned buildings in the wilderness are very attractive to all sorts of uninvited guests; mice, rats, snakes, insects, etc. Unfortunately, these can do damage to equipment, as evidenced here:
Mouse-infested power panel, remote transmitter site
Thus, some steps need to be taken to secure transmitter sites, generators, outbuildings, and even vehicles from mice in particular. Mice can squeeze into a hole that is .7 inch (17 mm) in diameter when they are fully grown. In many transmitter buildings, this leaves lots of opportunities; coax feed through ports, ingress holes drilled for wires, electrical service entrances, cooling fans, gaps under doors, soffits, etc.
Many people simply call the pest control people who will come and put poison out. That does not solve the problem and can in fact make it worse. If the poisoned mice go outside to die, they are eaten by the snakes and birds that naturally control mice in the wild. Those animals then die from the poisoned mouse. Meanwhile, new mice are being reproduced every 20 days or so. Fairly quickly, the bait is consumed, the mice no longer have any predators to naturally keep the population in check and there is a mouse explosion.
Large hole, formerly a vent for propane heater, covered with aluminum rack panel black.
The best way to keep them in check is to seal up the building as much as possible. For some reason, coax entry ports are often left open. This is very easy to fix and whenever tower crews are running new lines, ensure that they apply the correct boot for the port and line.
Deteriorated door jamb was replaced with pressure-treated wood
Another thing that happens; door jambs deteriorate or the bottom of steel doors begin to rust away. This opening is very attractive to insects, snakes, mice, and even plants.
Generators need special attention. Radiator and ventilation openings should be covered with chicken wire. This can be attached to the metal housing with self-taping screws and fender washers. Be careful and look inside the housing to make sure that the area inside the housing where the screws are being applied is clear of wires and hoses.
Stainless steel pot scrubbers fill gaps around conduit and fuel line
Ingress for fuel, control, and electrical conductors need attention as well. I found stainless steel pot scrubbers to be effective for filling gaps around these conduits and pipes. They are available on Amazon or many other places.
New Power Panel, an expensive lesson in pest control
Other openings can be filled with a combination of pot scrubbers and spray foam. Using spray foam alone often does not work, as the mice will chew through it.
I also keep a can or two of bee spray at most sites. Bees, hornets, and paper wasps love to make nests in propane tank fill covers, ATUs, under air conditioning units, or anyplace else that are sheltered from the rain.
It is a little bit blurry, but the real problem is that none of the indicator lamps on the phasor or antenna monitor are working. Those little incandescent 387 bulbs burn out frequently. It is difficult to tell, at a glance, whether the phasor is in daytime or nighttime mode. One also cannot tell which tower or mode is selected on the antenna monitor.
It is a small job to replace them, but it does take some time. They currently exist in older transmitters, studio consoles, meter backlighting, and other control indicators. Since I began working in radio, I have replaced hundreds of these little lamps. I would rather spend my time on more interesting projects.
The 387 bulbs cost about a dollar each and last less than a year, in most cases. Fortunately, there is a solution to all this. Enter the based LED replacement lamp. These little guys have the long life of an LED (100,000+ hours) in a package that is a direct replacement for the Incandescent lamp. They run about $5.31 each.
Dialight makes a very handy cross reference:
Dialight Incandescent to LED cross reference
The entire cross-reference section is three pages long and is a part of their PMI catalog. The full cross reference .pdf can be found here.
Those Dialight LED lamps are available from Mouser, Allied, and Newark Electronics.
Time is money. There are much better things to be doing than going around replacing incandescent indicator bulbs in various pieces of equipment. At the same time, it is important to know what the status of that equipment is at a glance, which is the reason for using any type of indicator in the first place. Using drop-in replacement LED indicating lamps with certainly save time and money in the long run.
I went to do maintenance at one of our sites and noticed that a certain transmitter was running at half power. Followed the path of the fault log and found this. When I mentioned it to the station staff, they said, “Yeah, we noticed it sounded a little funny…”
This is the second time this has happened with this particular transmitter. In any case, this is what I get paid for, so I am certainly not complaining. If only every problem where this easy to find.
When I get back out there to replace this, I will bring out my network analyzer and sweep the antenna and transmission line to make sure there are no issues with that. In addition, I will double-check all the grounding to make sure the copper thieves have not made off with any critical components like the ground buss bar or #2 solid down lead wires.
