[Another Dumb question catagory - trailing antenna

Hi!

I have antother question about antennas, i have seen that some planes have infront of the ADF antenna another two smaller mast with an aereal cable on them, some pilot told me that those were made to help the ADF to know wether the plane was going to the station or was getting away from the station....but.... Is this true? and why not all the planes has this feature, thanks so much!

Avenger in Action has a picture of a TBF Trailing a wire. The caption says it was for long range com. And they hoped the crew would remember to wind it in before landing.

The old aircraft used AM radio receivers and transmitters. Some path finder aircraft were fitted with HF (High Frequency) radios and had the HF antenna trailing from the aircraft. This was to prevent static and loss of signal while airborn. The use of trailing antennas was discontinued after the engineers discovered coax cable to shield from interference.

I'm not too sure about the air aspect of these cables, but I do know that Naval ships use them quite extensively. They are used for a couple of things on ships, such as Anti-Torpedo decoys and VLF / ELF (Very Low and Extremely Low Frequencies) radio antennas.

The AT cables (or Nixie, as it's called) are charged with an electro-magnetic signal that draws the torpedo to the wire, making it think that it is actually the ship. It can also be used as a short range EMP device.

The VLF or ELF have incredibly long waveforms, requiring very long antennas to be able to broadcast / receive signals. i can only assume the same use is true for aircraft.

Scott