[Amps] 500 uh plate choke

John Lyles jtml at losalamos.com
Thu Jan 24 07:34:28 EST 2013

K5UJ posted a really great idea to test an RF Choke for resonances, 
without needing even a GDO, (although every ham should still have one of 
these - in addition to an Almost All Digital L/C IIB meter!). Hams come 
up with the greatest ideas for simple methods of doing complex 
measurements with little expense, this forum remains the best!


Message: 6
Date: Tue, 22 Jan 2013 17:30:04 -0600
From: Rob Atkinson <ranchorobbo at gmail.com>
To: Vic K2VCO <k2vco.vic at gmail.com>
Cc: Amps reflector <amps at contesting.com>

you can test your chokes yourself.  Get a modern solid state ham rig
and fix it so it puts out around 20 watts cw.  dump the RF into a 50
ohm resistor and put a T in the line.  Connect the stem of the T to
the choke; the cold end of the choke connect to a 5 or 10 watt
incandescent lamp shunted to the feed shield.  if you have a scope put
it in the line with the lamp using a feedline probe.  Spin the VFO on
the rig across all the bands and see if you see the lamp light or any
RF on the scope trace.


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