[Amps] Tuned inputs

[Jim Thomson]

Date: Sat, 17 Apr 2010 09:29:29 -0400
From: "Carl" <km1h at jeremy.mv.com>
Subject: Re: [Amps] line length magic


Henry uses a broadband input for the 8K that seems to function. It is a 
stack of 3 ferrite toroids with Hi bands/Low bands switching. It can be 
purchased as an individual part.

As they say, YMMV!

Carl
KM1H

##  It's a basket case excuse for a 'tuned input'
It consist of 2 un-uns nose to tail.  They step the Z Up.. then turn around,
and step it back down.  Same deal on all bands except 10m.. where
they change step down ratio. A relay used to toggle between the
2 x output un-un's.    So 3 x un-un's in total.  

## No flywheel action anywhere.  The 8k uses a 3CX-3000A7,.. that has
a 47-50 ohm cathode Z.    The 8 k manual states NOT to use the auto tuner
in your xcvr.. and to just ..'put up with the high swr'.   Apparently, things really 
go screwy when the auto tuner used.  With a real tuned input,  input swr is flat,
and way less drive required. 

later... Jim  VE7RF