Value of New Comm Antenna?

wiwarrior

I have a 74 Piper Warrior & recently put in a Garmin SL-30. I had it at the shop for an avionics tuneup & the tech suggested I replace my original 'bent rod' comm antenna. I plan to go back in 2 weeks and am considering getting it done. The only somewhat related info I can say is I have flown out of reception before with my SL-30, meaning I could only hear the controller with 'squelch off'.

The tech said he sees issues with those older antennas. The new Comant antenna is about $200 + install. I trust the shop & don't think he's just trolling for $$. My coax seems O.K., I guess it would get a closer look with the new antenna. At this point I am leaning towards going new.

Bob H

HI wiwarrior,
The very earlier models of comm antennas were designed and effective for 360 channels. They don't perform well on 760 channels. If your's goes back to the sixties and seventies, it should be changed. How do you know that your coax is okay? Frankly, if it is old RG-58 from a similar vintage, it too is very suspect and I would replace it at the same time I replace the antenna. The dielectric qualities of RG-58 breaks down and effects performance. You've got a great radio there! Think of your antenna and coax as the "plumbing".
Even a new toilet won't flush right if the plumbing is bad! Bob Hart www.AvionixHelp.com

wiwarrior

Glad to hear your opinion Bob. Yes, I do plan the new antenna when I go back, I'll ask about the wire too. The current antenna is original with the 1974 plane. I am happy with the radio, when there is no squeal.

wiwarrior

Not able to edit. I went back to the shop because of an annoying, intermittent, radio squeal during transmit. I had trouble shot most everything, ignition, intercom, headsets, alternator. The shop found an internal problem with the radio, 'modulation problem'. Anyway, the radio is back to Gamin under warranty. When I go back I'll get the other items upgraded.