Using a small electric winch has a safety advantage over other methods: if something gets stuck they will stall rather than break the lifting cable (or worse yet, pull the tower over). If you pay att
3M EPS-400 is an adhesive lined tubing with a 4:1 shrink ratio. Ken K6MR All: Is there shrink tubing that will reliably shrink by a 4:1 ratio? I tried using some tubing I had on hand to cover several
Which is why you want the antenna torque balanced. Then it doesnt matter what direction the antenna is pointed, or where the wind comes from. Modern software makes it easy enough to do that there is
Sufficiently advanced technology is indistinguishable from magic. Dont worry. Thousands (millions?) of them are out there. I had a tower go down decades ago due to improperly installed cable clamps (
Something must have changed recently: I have purchased 30 sets of bolts for 25G from Hill Radio within the last year or so and all worked well. The bolts I just checked are a mixture of JH and JDF ma
Why do people insist on putting the first section in concrete? If you read the K7NV analysis of guyed towers it is far better to use a pier pin base. Less stress on the tower and the problem of rust
I bought a used TH354 as my first tower in 1967. This was one of a series of guyed crankups that Tri-Ex made in the 60s and a little into the 1970s. The series was the T, TH, H, and HS, in heights fr
Max Gain Systems http://mgs4u.com/index.html Ken K6MR I want to experiment with building a 2-element half-WL wire-beam for 40m. I know that Cubex sells fiberglass poles I could use for spreaders. Doe
The guys you have to watch for are the dirt strips that pop up out of nowhere. Ive got a neighbor that comes over the towers at 300 feet or so on final to his dirt strip. As I understand it the strip
PSTRotator by YO3DMU. Ken K6MR I'm working on setting my station up as a 'glass panel' station. All of my equipment will be rack mounted and controlled via my pc, and a couple monitors including a to
W8JI has a photo on his web site of 110 feet of 25G being taken down with a crane. He put the sling at 75 feet and it was ok. He noted that the sling should be in the middle of a section and wrapped
Ive wondered this myself but never bothered to model it. Here are some rough figures from Yagi Stress: Reflector element without the tee: 2.88 sq ft. Driven element without the tee: 2.76 sq. ft. Refl
Thanks Joe. I was thinking about wind vectors but didnt work it through. With these numbers it should be simple to add a torque compensator to make up for the higher torque generated by the reflector
Ok, this even makes mathematical sense (as it should): Assume the wind angle is with respect to the antenna direction. Total area = Element area * COS (angle) + Boom area * SIN(angle) First derivativ
All the more reason to be sure that the antenna is torque balanced. Those shifting winds can beat a rotator to death (not a prop motor, but all regular ones). I can loosen the bolts on my reasonably
You are without a doubt the Excel Master :^). I couldnt live (er, at least do any antenna sims) without AutoEZ. It is amazing. Ken K6MR I'd like to add a "me too" to that thank you. Nice mental exerc
OK Jim, I need that explained. If the wind is at 45 degrees to the boom, how is there not a contribution of force by both the boom and the elements? Ken K6MR You don't need to be concerned with equal
Thanks for the link. This is definitely not an intuitive result. The good thing is that the loads are smaller using this procedure. Yagi Stress calculates these loads, but Ive never done pencil and p
Ive been trying to find an archive of Communications Quarterly but no luck so far. This obviously takes some study to understand (at least for a non-mechanical type like me). Grant: your idea of adju
I have two of the KK1L switches. They work well. As they say, some assembly required. But overall a nice design. As for a band decoder: assuming you have a radio with (DCBA) outputs, Unified Microsys