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Re: Under skin Aerials/conduits etc.

Subject: Re: Under skin Aerials/conduits etc.
From: Mike Cowgill <zeus@myth.demon.co.uk>
Date: Sat, 27 Apr 1996 20:43:42
In message <31823B55.35DF@wow.net> Ember writes:
>Tony Renshaw wrote:
> 
>> Dear Richard,
>> 
>> Any tips on the installation of your conduits, and detail on what a "BNC
>> Connector" is, would be great.
>
>A BNC connector is a "Bayonet Nut Coupler" which is a coaxial plug and 
>socket, available, as "in line" or "panel mounted" versions.    Its virtue 
>is that it maintains a 50 ohm impedence, same as your coaxial cable.   Not 
>too easy to solder in place, but not impossible !

Close. 
       BNC = Bayonet Neil Concelman
       TNC = Threaded Neil Concelman
       
According to the IEEE (Institute of Electrical and Electronic Engineers) 
journal "Spectrum" in which Neil Concelman was interviewed and explained the 
design ideas. As Tony says, they maintain constant impedance along the 
transmission line (connectors like PL259/SO239 don't) which basically means 
that more of the tranmitter power gets out and more of the received signal at 
the antenna actually gets into the radio. They are also mechanically quite 
resilient .Full size 'N' connectors (which actually have the same connecting 
hardware) are better but are larger and heavier. They are suited to repeated 
plugging/unplugging and are common on low/medium end professional equipment. 
The Bayonet version is faster but more susceptible to oxidation and impedance
discontinuity.

Mike G1VOX (no, not G-IVOX sadly)

P.S. They aren't difficult to assemble when you get the basic idea. They are 
     well worth the extra effort. You are building an aircraft after all!



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