The line was Heliax, about 1.5”, installed in 1949, and lasted about 40 years. When I was involved, it was just over 10 years old.
It was just a short run; I’d estimate about 70 feet total. Just a 30 foot tower on a 4-story building, fed from the first (and-a-halfth) floor.
Antenna height above ground about 80 feet, and above average terrain about 24 feet (sorry to say).
What we worked with was in 400 ft. coils. So there were a number of splices. connectors do not seal perfectly. And I can assure you that the temp dif on a 150 ft. run is huge and the condensation problem is bad.
It was just a short run; I’d estimate about 70 feet total.
What we worked with was in 400 ft. coils. So there were a number of splices. connectors do not seal perfectly. And I can assure you that the temp dif on a 1350 ft. run is huge and the condensation problem is bad.