Can you use a COM antenna with a hand held in NAV mode?

[crusty old aviator]

I have a COM hand held that I use with a TSO'd COM whip, mounted on the belly of my antique. It works great, but what if I were to use a NAV/COM hand held? Would the CDI, etc. work using the COM antenna? I'm not planning on doing this "on top," but I'm curious how accurate the NAV functions would be using the COM antenna.

[Mike M]

I do. It works.

Narco HT870

[Derswede]

I agree, it will work fine. The VOR frequencies are in the range of the comm frequencies, so the antenna will be close to resonant, and a handheld will do well with one. Try to use a direct connect to the radio (no adapters) as you will stress the connector on the radio less. I have broken several connectors on ham radio hand helds using adapters. Much better than the short stock antenna.

Derswede

[FlyingRon]

The major difference between a VOR/LOC antenna and the COMM antenna is polarization. Comm is vertically polarized, Nav is horizontal. Of course, the rubber coated dummy load on you handheld isn't really a circular radiator either. It probably works as poorly in any orientation (though you can try tilting the radio to see if it helps with reception).

[Eric Page]

Shamelessly copied from Wikipedia, here: https://en.m.wikipedia.org/wiki/Airband


The VHF airband uses the frequencies between 108 and 137 MHz (https://en.m.wikipedia.org/wiki/Hertz). The lowest 10 MHz of the band, from 108–117.95 MHz, is split into 200 narrow-band channels of 50 kHz. These are reserved for navigational aids such as VOR (https://en.m.wikipedia.org/wiki/VHF_omnidirectional_range) beacons (https://en.m.wikipedia.org/wiki/Beacon), and precision approach systems such as ILS (https://en.m.wikipedia.org/wiki/Instrument_Landing_System) localizers.

(https://en.m.wikipedia.org/wiki/Airband#cite_note-freq-3)As of 2012, most countries divide the upper 19 MHz into 760 channels for amplitude modulation (https://en.m.wikipedia.org/wiki/Amplitude_modulation) voice transmissions, on frequencies from 118–136.975 MHz, in steps of 25 kHz. In Europe, it is becoming common to further divide those channels into three (8.33 kHz channel spacing), potentially permitting 2,280 channels.

Even if your antenna is tuned to the center of the comm band at 127.5 MHz, it should work fine. A few MHz one way or the other in antenna tuning will make little noticeable difference except at the extremes of range, and as Ron pointed out, you'll lose a bit on the polarization issue, but you're probably not expecting panel-mount performance from a handheld anyway. Go forth and navigate!