[ARC5] Antennas

[Mike Hanz]

On 3/1/2011 9:01 AM, Robert Eleazer wrote:
> A discussion over at the Army Air Forces forum, where I explained to the assembled and no doubt awestruck multitudes that the "antenna mast" seen on some aircraft (Pacific P-40 was the example in question) was in fact simply the lead in for the real antenna - the wire going back to the tail - leads to this question:
>
> Was the AN-104 wooden metal covered antenna you can see in so many pictures (and in old Fair Radio catalogs) always simply just a way to hold the wire antenna for the 274-N up or was it also used as a VHF antenna?

It was designed from the start as a VHF antenna, Wayne, was a improved 
version of the AN-74 mast.  There were several different version of 
these masts, at least one being uninsulated, but the AN-104 used a 
copper cladding to provide an antenna that covered ~100-140MHz with a 
remarkably low VSWR.  Somewhere around here I have a plot of VSWR vs 
frequency but it's MIA at the moment.  Its use as a standoff for wire 
antennas came as an aside, I suspect - drill a hole in the tip and you 
have a convenient hanger.  The drawing I posted at 
http://aafradio.org/sidebar/AN-104B_outline.png warns the installer not 
to have the attachment wire to the insulator extend more than 2" from 
the mast.

73,
Mike  KC4TOS