Where are the actual antennas?

deyoung

Line Up and Wait
Joined
Nov 13, 2014
Messages
508
Location
Tucson, AZ
Display Name

Display name:
Chris
For larger airports, mostly class C (and B I assume) that have approach and departure control, where are the actual antennas they transmit and receive from located? Are they physically on the tower, generally, or elsewhere?

I know ARTCC centers have remote antennas all over, but I'm guessing that approach and tower are usually at the tower... but maybe I'm wrong.

This is relevant since I've been troubleshooting a radio problem that has me using a handheld on and off, and since I'm transmitting from inside a metal box it has pretty limited transmit range. (I'm adding the external antenna connection for it at me earliest opportunity.) So, since I know I have to be reasonably close for them to hear me, can I assume that it's the tower I need to be reasonably close to? :)

I don't expect to be able to maintain contact with center on a handheld, but I'm based at a class C and do need to be able to get in and out of there on it.
 
I at some point have been told that at large airports, MOST of the comm antennas are on remote antenna arrays and some on the tower. At smaller class D fields, on the tower. I could be wrong though. I know a guy that works on the radios and radar systems for the FAA. I'll ask him about it and get back to you.


Sent from my iPhone using Tapatalk
 
Depends on the facility. Back when Dulles Approach was actually just below the tower cab at Dulles, the antennas sat there on the side of Route 28 near the airport fuel farm.
Now the approach facility is 30 miles down the road at the consolidated TRACON. I have no idea if they just remoted the existing antennas or they built new ones.

Washington Center has a giant HF array on a tower right outside the building.
 
For larger airports, mostly class C (and B I assume) that have approach and departure control, where are the actual antennas they transmit and receive from located? Are they physically on the tower, generally, or elsewhere?

It depends on the area, but often there are remote transmitters on the fields of other airports in the region.
 
I've seen antennas next to a road while riding my motorcycle. Probably about 40-50 miles away from a Class C airport. The sign on the fencing said it was an FAA facility(don't remember the exact wording but it was definitely for aviation).
 
(I'm adding the external antenna connection for it at me earliest opportunity.)

If that is the picture of your airplane in the avatar, just go down to your local NAPA aviation parts house and buy a couple of feet of thin (0.010" or thinner) shim brass. Cut a strip from it 1" x 21" and fasten (tape of some sort or rubber cement) it diagonally to the pilot or passenger side window. Put one end of it VERY near any screw holding the window or trim in, making sure that the screw somehow is attached to the door metal mongery.

Before you attach the strip to the window solder the center conductor of a piece of RG-58 50 ohm coax to one end of the brass strip. The conductor should be as short as possible, certainly not more than 1" or so. Take the braid and crimp a ring connector onto it. Fasten strip to window and ring connector to the ground screw on the window frame.

This is a TEMPORARY lash-up antenna. Put the external antenna on as soon as reasonably possible.

Jim
 
If just calling the Tower and asking doesn't work, you can DF it with your handheld, on foot (at least while measuring).

You can get a rough bearing by tuning the receiver so signal is discernible from noise, but only barely. If it's real strong, remove the antenna and/or tune to the next frequency to make it weaker. Place the receiver against your chest, and rotate in a circle. When the signal is weakest, the bearing is directly behind you. Do this in two or more spots, and you can triangulate the transmitter's position.

Of course, that technique works best if someone is transmitting nearly continuously (it's OK for ELTs, though other techniques are more sensitive). If it's quiet, you're gonna get nothing.
 
Back
Top