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Re: [Amps] GS35B Idle Current drifting up.

To: Colin Lamb <k7fm@teleport.com>,amps@contesting.com
Subject: Re: [Amps] GS35B Idle Current drifting up.
From: Paul Baldock <paul@paulbaldock.com>
Date: Fri, 20 Dec 2013 12:58:22 -0800
List-post: <amps@contesting.com">mailto:amps@contesting.com>
I don't know much about the inside of tubes, but it seems to me that if the grid was getting smaller then it would take a large negative voltage to stop those electrons getting to the plate.

The real gain (at rf) has not changed significantly.

- Paul

At 09:54 AM 12/20/2013, you wrote:
Hi Paul:

Generally, with age, a tube can go "flat", which means reduced gain, which means you need to reduce the negative bias voltage to run the same current. You have the reverse, and we know that gain of tubes does not generally increase. So, I suspect something else. Perhaps the filament voltage has increased slightly, which causes more gain of the tube.

73,  Colin  K7FM

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