[AMRadio] Building

jeremy-ca km1h at jeremy.mv.com
Tue Dec 4 13:53:15 EST 2007

My last 4X1 amp, back in the 80's, ran a pair in AB2. I used swamped grid 
input with a toroid 4:1 step up from the T4XC to get the necessary grid 
voltage. Screen and bias were all SS rectifiers but tube regulators.

With 5200V it put out some serious power. Since it was a build to order it 
got only minimal air exposure here but the customer was happy. It is now at 
its 3rd home.

Ive been wondering, besides the drive requirement, why swamped grid cant be 
used in Class C? It would eliminate the neutralization requirement with some 
tubes as well as the hassle of a bandswitching input.


----- Original Message ----- 
From: "rbethman" <rbethman at comcast.net>
To: <cemilton at aol.com>
Sent: Tuesday, December 04, 2007 1:19 PM
Subject: Re: [AMRadio] Building

> Chuck,
> No pictures as of yet.  I've got a Harris 4KV power supply for plate 
> power.
> I'm looking at developing bias supply(s) for the 4-1000a, and driving it 
> OTHER than GG.
> I figure I can get a better rig by doing so.
> Bob - N0DGN
> cemilton at aol.com wrote:
>> Say Bob............
>> Got any pictures of that 4-1000A lashup?
>> I've been collecting parts for a 4-400 amp and hope to start on it in 
>> January when the temps get a bit cooler in the shop.
>> Have a DX-60/HG-10 just waiting to drive something.
>> 73
>> W4MIL
>> Chuck
>> Palm Coast, FL

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