All, has anybody had any real success with the switching method described in the ARRL Antenna Handbook using one coaxial relay and a length of 93 ohm line to switch from LHCP to RHCP on crossed yagis? I have tried this method several times and there appears to be very little difference in signal level. I seem to think that the 93 ohm cable is close enough to 75ohm and becomes a transformer instead of the delay line that the idea is trying to achieve. I also seem to think that for this idea to work properly that the delay line impedance should be in the vicinity of 110-125 ohms. I have seen many methods using two relays, and yes that would have to be the surest method of accomplishing this. However, for ease of construction I like the single relay method. I have constructed these to the letter using only one velocity compensated ¼ wave length of coax on the 75ohm transformers and on the delay line, thats were I thinking that the transformer sections and delay lines should perhaps be long odd multiple of a ¼ wave length, i.e.; 3/4 , 5/4 etc to see a better impedance match. Any ideas from past experience would be appreciated.
Best 73s Frank VK5KV _______________________________________________ Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
