VOR antenna

popaviator

popaviator

Well-Known Member
I was pre flighting an aircraft today and a thought popped into my head. Normally on a 172 a v shaped antenna is on the vertical stabilizer. I'm curious how the signal is transmitted between 2 VOR's. Even if there is only 1 VOR there is still a V shaped antenna... So how is that reception distributed to both VOR's.

maybe the answer's right in front of me...idk....i'm tired :insane:
 
It's just one antenna isn't it? You tune in a frequency and it will send the signal to the reciever.. Like if you are flying the ILS and you have both nav and gs signals going though the same antenna.. right?
 
If there are two VOR receivers, but only one antenna, then there is a splitter (similar to what is used with a TV) somewhere in the aircraft. If glide slope transmitters are involved as well, then a diplexer may come into the mix if the radio(s) have separate connections for VOR/LOC and glide slope antennas, as they operate on different frequency bands.
 
Barty said:
If there are two VOR receivers, but only one antenna, then there is a splitter (similar to what is used with a TV) somewhere in the aircraft. If glide slope transmitters are involved as well, then a diplexer may come into the mix if the radio(s) have separate connections for VOR/LOC and glide slope antennas, as they operate on different frequency bands.
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Thanks! :D
 
juxtapilot said:
It's just one antenna isn't it? You tune in a frequency and it will send the signal to the reciever.. Like if you are flying the ILS and you have both nav and gs signals going though the same antenna.. right?
Click to expand...

The GS antenna is usually on the bottom of the fuselage, separate from the nav (LOC).
 
Grabo172 said:
The GS antenna is usually on the bottom of the fuselage, separate from the nav (LOC).
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I thought VOR/NAV/GS shared the same V shape antenna, and just used the splitter to send the signal to the correct radio? Which antenna is GS on the bottom.. Transponder, ADF, Marker beacon, secondary COM perhaps and GS is there too?
 
JulietBravo said:
Just curious, where? Can you see it physically? Or is it still inside the fuselage on the bottom?
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Some aircraft have separate glide slope antennas, others do not. Antennas on the bottom of most light aircraft are usually for the marker beacons, transponder and possibly ADF (assuming it is still installed).

Without going into too many technical details, it is possible for an antenna to be resonant on multiple frequency bands, thus eliminating the need for separate antennas.
 
Well that's what I first thought. I've always been under the impression that the VOR antennas on the tail are also used for LOC and GS; all essentially sharing the same antenna. I don't have much experience with older planes and different style antennas. I've just never heard of a separate GS antenna.
 
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