Tree,
The choke that's used in the Ameritron is another excellent replacement. It
was designed by W8JI. It has double the inductance on 160 so you don't need
as much tuning cap to achieve resonance.
Again, my 2 cents...
73 Hardy N7RT
----- Original Message -----
From: "Tree" <tree@kkn.net>
To: <amps@contesting.com>
Sent: Monday, March 24, 2014 11:17 AM
Subject: [Amps] Alpha 77 160 meter plate choke
All -
I have made a mod to my Alpha 77 to add about 60 uH to the RF plate choke
when on 160 meters. I originally was going to mount a switch to control a
HV relay - but came up with a better solution. If you are interested in
knowing more - check out the pictures here:
http://www.kkn.net/n6tr/directories.html
Look under Alpha 77Dx. The relay was purchased from Henry Radio. It has
a
26.5 volt coil which seems to work just fine off of the +24 volt regulated
power in the amp.
I added a 4700 pf 6KV cap from the HV to ground which you can see in the
pictures.
I am not sure this makes a big difference - but I certainly feel better
about using the amp on 160 with this mod.
73 Tree N6TR
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