ADF Antanna

[studfiver]

I am looking to change the old clothes line style adf antanna on my 1975 m20f, any suggestions to what is the best way to go about it?

[Guest Anonymous]

Older ADFs have two antennas, a "sense" antenna used for radio reception and seeking, and a "loop" antenna used for the radio direction function.  The replacement of your "Clothes Line" depends on your ADF manufacturer, but most have an antenna like the KA-44B used with the Honeywell/King KR-87.   That is a loop/sense antenna that will let you get rid of your "Clothes Line" sense antenna.  You take off the existing loop antenna (A KA42 would be typical for a King ADF and replace it with the KA-44B.  The antenna connection for the old sense antenna can be moved or eliminated.  The cost for a DA-44B is typically around $800.  Some systems may also require a convertor that splits the signal from a single antenna connection into two as required by the older ADF.  This is usually fairly cheap.

The loop/sense antenna is usually larger that the one it replaces, so mounting it on the belly is not a problem.  It also makes a handy skid plate if you are unfortunate enough to ever do a gear up landing as it is the first thing that usually hits the ground.