SQ 314 Emergency Services Tip # 05 August 8, 2008

Locating an ELT on the Ground with a Handheld Aviation Radio

Typically, an ELT is located on the ground with an L-Per directional receiver. It is possible however to locate an ELT with a handheld aviation band radio.

Since the ELT transmitter and the handheld radio are omni-directional, it is necessary to block the signal from the ELT with something like your body.

This technique applies to ELTs in the 121.5 MHz and practice beacons in the 121.775 MHz range.

Technique:

Turn the receiver to the intended frequency (121.5 or 121.775).

Hold the radio in front of you waist high.

When an ELT signal is first received, it will most likely be too strong to block with your body. Several techniques can be utilized to attenuate the signal to allow direction finding by blocking.

Turn the volume up high

De-tune the frequency until the sound is weak

Turn up the squelch until the signal disappears.

Rotate your body 360 degrees looking for a null. When the signal nulls, the direction to the beacon is behind you.

Noting the direction, move to another location and repeat the process.

Where the two directions cross is a potential location for the beacon.

Advance to this intersection and repeat the process.

When the offending beacon is located, it should be silenced.

Vernon H. Parsons, Lt.Col. CAP

SQ314 Emergency Services Officer