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Ask a Tech: Poor VHF Radio Performance

Just because you spent big on the latest digital comm transceiver doesn’t mean it will perform any better than the one it replaced. Antennas matter—a lot.

Larry Anglisano
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Edited By:

Larry Anglisano

That’s the top of an older Legend Cub and the VHF comm, ELT and GPS antennas installed. Antenna installs are challenging on fabric-covered aircraft like this because there might not be a sufficient ground plane for optimum performance. In some shortchanged installs, the systems might not work at all without sizable rework.

Two questions related to VHF radio performance came in for this month’s Ask a Tech feature, and both problems could yield similar solutions. The new owner of a Citabria brought the airplane to his mechanic to have a new Trig Avionics standalone comm radio installed. The other with an older Cherokee had his shop install a new Garmin radio.

Unfortunately, both owners are having issues receiving anything unless they’re close to the station, and the Citabria owner says controllers complain of weak and garbled transmissions. These aren’t the problems you’d expect after writing a $5000 check for installation.

Larry Anglisano

Editor in Chief Larry Anglisano has been a staple at Aviation Consumer since 1995. An active land, sea and glider pilot, Larry has over 30 years’ experience as an avionics repairman and flight test pilot. He’s the editorial director overseeing sister publications Aviation Safety magazine, IFR magazine and is a regular contributor to KITPLANES magazine with his Avionics Bootcamp column.