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[AMPS] ALC from SB-200 reduces FT-900 power on CW

To: <amps@contesting.com>
Subject: [AMPS] ALC from SB-200 reduces FT-900 power on CW
From: w0opw@yahoo.com (david wintheiser)
Date: Fri, 25 Sep 1998 09:04:26 -0700 (PDT)

> Pat,
> The 10-160L is a bit of a dog but it should work fairly well on 160.
Just
> think of it as the ancestor to the Clipperton L !
> What sort of problems, fixes and changes did you have and make?
> The primary problems in the output of that amp are bandswitches and
> loading caps.

> I buy 2-3 a week to convert to 6M. They are indeed a bargain
considering
> what you get and 1000% easier to work on than the Yaesu FL2100 wannabe
> clone.
> Plus parts are readily available.
> 
> 73   Carl   KM1H

 Carl, it seems the list is endless considering the guy who sold it to
me swore that it worked just fine at the flea market !.
 I replaced: bank of diodes; Bias Zener; Bias relay;   1 HV meter
resistor; plate meter resistor(never tried to do that before!); ripped
out the primary supply relays and changed to simple rocker switch;
moved bias relay and switch from output deck!; added nichrome wire to
filament leads to drop supply from 6.6v to 6.25 volts(ala Rich
Measures); New tubes(572b's) as original 811a's there were 3 different
manufacturers for the 4 tubes; Redesign of the tank is needed cuz my
calculations showed they were driving 160 meters with Q of 3500. 
Can't see how anybody got any power out that way.    
 At this point the band switch is burned up and still need to design
best Q for 160 and 80 m. Am planning to use just 2 572b's on 160 & 80 m.
   Aren't you glad you asked !
        Pat W0OPW  
   



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