Comm Receive and Transmit Issue

[svyolo]

I have a Comant CI-122 antenna as well, mounted forward on the tunnel, and a MGL V-16 Com radio. Seems to RX fine. The MGL Razor control head has a function where it tells you what the SWR measurement is. Mine is marginal at the lower end of the frequencies (1.7) and it gets worse, nearly linearly, as frequency increases. I get a Antenna Warning (SWR >2) at about 127 Mhz, and worse than that at the upper limit of freq. Maxs out at 3.5.

I am not an antenna expert. I will check the cable when I get a chance.

[gregc]

SWR basics are here: https://www.arrl.org/files/file/Tech...f/q1106037.pdf. Personally I wouldn't be concerned about SWR, especially under 3 (I think a "warning" at 2 is silly). Use quality low loss coax, make sure your connections are good and that you have a reasonable ground plane and it should work just fine.

[svyolo]

Thanks I will have a read.

[SpruceForest]

Having flown aircraft with antenna manual diversity (top and bottom cockpit-switchable antennas) bottom usually worked great for airborne use and chatting with ground-based radio operators, but could be finicky for talking to airborne aircraft when on the ground. The reverse was true for top-mount antennas. With a single radio, I think it's a coin toss, but seems like top-mount antennas on SEL are perhaps a bit more popular than belly mount, if only because Cessna and Piper made a bunch of airplanes in years past. Sounds like a lot of good advice on getting things working right before you give up on the current location.

[Battson]

This is a good summary and mirrors my experience with a belly-mounted antenna. I've found it is largely the same as at wing-top mount in 99% of operational situations, save for a few unique situations like trying to call another ground station many miles away where lots of physical obstructions (trees and buildings) block the path. But on the other hand, when airborne there seems to be no difference whatsoever.