[lr172]

I stripped 40" of shielding from some coax and f/g'ed to the cowl for a Marker Beacon antenna. I am wondering if I need to ground the shield. I soldered a wire to shield where it was stripped so that I could ground it, but now wondering if that is necessary or appropriate.

I appreciate your guidance here.

Larry

 

[flightlogic]

I would ground it. Remember, you have half an antenna (without counterpoise) if you let it float. The MB signal is 75 mhz.... pretty low for aviation.
You are not looking for much range, just flying over the top of the transmitter. But, I would suspect some lack of sensitivity if you don't ground it.

 

[lr172]

Thanks for the input. I thought that it would be necessary.

Larry

 

[az_gila]

I wouldn't bother, there is no metal ground plane behind it if your exposed wire is in the cowling.

This is what Bob Archer says...

Marker Beacon antenna: A simple and cheap antenna
can be fabbed by installing a 40" long conductor in a
wing tip under the wingtip VOR antenna about 3" from
the end of the metal of the wing. Connect a center
conductor of a coax to one end of it, ground the braid if
you like, not necessary, and you are home free.