[Elecraft] directional antenna

[Ron D'Eau Claire]

Plug "directional loop antenna" into your favorite search engine and stand
back. There are dozens, perhaps hundreds of web sites with design info on
the 'net.

Directional loops covering the 600 meter Marine Band were required equipment
on all ships until just recently. Can't tell you how many trips out I made
on a ship to turn circles and calibrate the loop after work had been done on
the ship - any movement of metal, etc., of any size would distort the
pattern. 

What the DF loops were required for was to chase down a lifeboat if someone
was using a 600 meter lifeboat radio after a sinking. The DF loop was used
on occasion to check position where other services such as LORAN weren't
available, although since the 1980's GPS did a much better job all around.

They are gone from almost all vessels today. The 600 meter lifeboat radios
have been replaced by VHF radios and satellite systems that report the
lifeboat's exact position using GPS to all ships involved in a rescue. But
that's a change that's happened only in the past 5 years. 

Ron AC7AC