Date: Tue, 10 Jan 2012 19:13:20 +0100
From: "Carel, pc5m" <pc5m@xs4all.nl>
Subject: Re: [Amps] Safety choke question
Hi Jim,
I suppose you would like to put that choke across the (50Ohm) output
terminal ? Think 225uH is not needed at all to have negligible effect at
160mtrs. I would go for a reasonable sized toroid (2 inch dia) and larger
dia wire. Than you know for sure something else will fail before you
"safety" is no longer in place....
Gl, Carel, pc5m
## here's what ICE does on their lightning arrestor. They use a 2.4" OD
torroid..and wind
it with 12 ga magnet wire. They end up with aprx 40-45 uh. That's plenty
for 160m. ICE used it
to dc grnd the center conductor of the coax at all times. I forget what type
of ferrite they used. I think
it was type 43.
## a buddy acoss town used the same scheme for the safety choke on his hb
amp. To do this right, put
once across the load cap, and a 2nd one across the RF ouput connector. Then
the coax is dc grnded on RX..
and it's also grnded on TX. Then your tune/load cap + tank coil + bandswitch
etc are also dc grnded...
on rx or tx.
later... Jim VE7RF
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