[Top] [All Lists]

Re: [Amps] 4-1000A Input matching

To: "'Ken'" <>, <>
Subject: Re: [Amps] 4-1000A Input matching
From: "Harold Mandel" <>
Date: Thu, 8 Jun 2006 09:40:48 -0400
List-post: <>
Dear Ken,

Since you plan on some renovation you might want to
look at a bunch of items.

Will you be running the amp with a Grounded Grid or
will you run Grid-Driven?

If you decide on Grid-Driven, the 4-1000A's will
really "come to life" for you, and provide you with
a superb machine.

In this case, installing a neutralizing circuit similar to
the Tetrode circuits Rich Measures AG6K has on his
website <> will provide protection for your
tubes, a better input match and a superior signal from
your amplifier.

The secret is to use a combination of small roller inductor and
air-variable capacitor in the neutralizing circuit. 

When combined with a toroid transformer to match the
input impedances of the 4-1000A's to the exciter, the
total input circuit is a simple affair that does all you need it
to do to achieve better efficiency.

Hal Mandel

-----Original Message-----
From: [] On
Behalf Of Ken
Sent: Thursday, June 08, 2006 8:21 AM
Subject: [Amps] 4-1000A Input matching

I picked up a grounded grid, dual 4-1000A, linear from a friend.
After building a 3000-6000 volt power supply, I would like to include
an internal tuned input to cover 80-10m. Does anyone have a suggested design
or diagram I may use?


Amps mailing list

Amps mailing list

<Prev in Thread] Current Thread [Next in Thread>