---- IM Ashford <[EMAIL PROTECTED]> wrote: > Any expansion due to heating of the heliax inner should be compensated by > expansion of the linking feeder inner,pushing the tuning bar upwards.
I had a set of homebrew 220Mhz duplexers made out copper pipe that would drift with temperature changes. I built a plywood box, put them inside, and added a small lightbulb controlled by a thermostat. This kept them very stable. There's no reason that you couldn't do the same thing for the coax duplexers. Not very pretty, but effective. Too bad the UK is so expensive to ship to. We just pulled out six 200 foot runs of Andrew 1 5/8" VXL7-50 heliax that was damaged at the top of the monople. It got chopped up into 6 foot lengths and dumpstered. (Not much value to this stuff). 73, Joe, k1ike
