[Milsurplus] Mounting Aircraft Antennas?

[Michael Hanz]

They frequently used a phenolic block, sometimes with cast clamp, just 
under the skin of the aircraft.  There is usually a rubber gasket to 
keep water from entering.  In any case, the clamp has to have the same 
shape as the bottom of the antenna.  If you don't have machine tools, 
it's a lot of work with a file....😁
- Mike  KC4TOS





On 10/26/2020 11:38 PM, KD7JYK DM09 wrote:
> I have recently acquired the following antennas:
>
> https://www.ebay.com/itm/Transponder-Antenna-AT-184-AP-AF-8351-Phaostron-Co-/283143629873 
>
>
> And:
>
> https://www.ebay.com/itm/Phaostron-AT-185-AP-Antenna-AF8351-/373205080085
>
> I found the "white bronze" alloy used for the connectors interesting, 
> although they have the stink of silver, but, my question is, how the 
> heck were they mounted????
>
> I found a drawing online showing a craft with such antenna on it, 
> mounted flush to the fuselage, but as you can see, there really isn't 
> any way to do this.  The nut on the bottom of each antenna connects to 
> a long rod passing through the antennas that pulls the three parts, 
> top element, insulator, and bottom element, together.  There is a 
> rubber gasket on the bottom of each antenna to seal between the body 
> of the antenna, and the surface of a craft.  The nut is split, and 
> crimped in, probably a sort of lock-nut.  Aside from that, there are 
> odd notches in the sides of each antenna.  These recesses are machined 
> into the aluminum lower portion, and there is a dull gray metal plug 
> in each one.  There is no corrosion, or oxidation, but each plug holds 
> a magnet very well.  I had a heck of a time getting a small "super" 
> magnet off of one, and the plug was quickly magnetized in itself.  The 
> lower portion of each antenna, aside from a small hole for the rod 
> that holds them together, and a small passage for the center pin of 
> the RF connector, from bottom, to top, is solid aluminum.
>
> Any ideas on how these would have been mounted to an aircraft?  I just 
> can't figure it out...
>
> Thanks.
>
> Kurt
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-- 
Michael Hanz - KC4TOS