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[AMPS] Safety RF choke

To: <amps@contesting.com>
Subject: [AMPS] Safety RF choke
From: philk5pc@tyler.net (Phil Clements)
Date: Wed, 11 Aug 1999 21:57:27 -0500
>I would like to make a new RF safety choke.  Does abt 3 feet (roughly
>1/4 wave on six meters) wound tightly single layer (solenoid style) over
>abt a pencil thick form using approx. 22 gauge wire sound like it would
>work?  Do I check it's resonant freq. with a GDO in free space when it's
>done?  Do I want this safety choke to resonate on 50 mhz???  Do I have
>any idea in the world what I am doing??  For the ongoing saga...stay
>tuned. Hi

Ohmite makes a fine line of suitable chokes for this purpose. A Z-50 or a
Z-14 will work very well. They are physically compact and  dipped in colored
pint. The Z-50 is red, and the Z-14 is orange!

If you really want to get fancy, cut a piece of RG-8 coax a bit over 40 inches
long; grid dip it and prune it to 50.100 mhz. put a suitable coax fitting on
one end of the stub, and short the braid to the center conductor on the
other. Install the stub with a  coax "T" connector at the antenna jack of the
amp. This gives you a "big time" connection to DC ground, and puts your
second harmonic down about 30 db. You can do the same thing on the
inside of the amp if you wish; just use small teflon coax for the stub, solder
it in, and coil it up.

(((73)))
Phil, K5PC



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