[Amps] Safety choke question

[Jim Thomson]

Date: Tue, 10 Jan 2012 19:13:20 +0100
From: "Carel, pc5m" <pc5m at 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