[MRCA] WWII German NVIS Antennas

[Rob Flory]

I think currents in top hat largely cancelled by currents in vehicle.  Dominant radiation still that of a short vertical.

As an anology, think of a  vertically-polarized full-wave loop.  I had one for 80m with 40-foot vertical portions with feedline in the center of one.  Horizontal portions 90 feet long.  Great DX antenna, dominant radiation from vertical sections, short as they were.  Nulls off sides not deep because the vertical portions are only 90 feet apart.  I split the antenna in 2 to get the verticals a half wave apart, and fed both "bracket" shaped halves, which also let me inverse the phase  to work endfire.  

RF

-----Original Message-----
>From: w8au at sssnet.com
>Sent: Jun 24, 2008 1:30 PM
>To: Military Radio Collectors Association <mrca at mailman.qth.net>
>Subject: Re: [MRCA] WWII German NVIS Antennas
>
>At 08:25 AM 6/24/2008, Rob Flory wrote:
>>Per the link below, the "feedline" was a single wire.  That means 
>>that in fact, the "feedline" was the radiating portion of a very 
>>short, top-loaded vertical.
>
>Heinz Guderian's vehicle "flat-top" was fed at the rear corner, which 
>makes it more of an
>Inverted L, which would radiate over all it's surface.
>
>A pure top loaded vertical would be fed at the electrical "center" to 
>keep the top hat
>balanced.  (ie: Marconi style)
>
>This could be compared to the TBW Marine beach setup, where the LF 
>antenna was a horizontal end fed at 25 ft height (or so) against a 
>low mounted "counterpoise" of the same length, and end fed to the 
>radio ground.  Something like a big radiating capacitor?
>
>Just some more "monkey wrench" to toss into the gears....:-)
>
>Perry   w8au 
>
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