The idle current does NOT change between standby and operate. It is over 100
mils
(just under the "second line" on the meter or almost 2/3rds of .2 amps.)
Doug KR2Q
----- Original Message -----
From: Mike Schatzberg
Date: Thursday, May 26, 2016 8:00 pm
Subject: Re: [TenTec] Centurion Amp - early model, looking for advice
To: kr2q@optimum.net
Cc: tentec@contesting.com
> Firstly, does the idling current change from standby to operate?
>
> If it does not change, and remains the same, you may have no
> bias at all. The triodes are zero bias tubes and will operate
> with no bias.
>
> That would explain why the tubes are running so hot.
>
> If the idling current is around 60 to 75 mils, there is bias
> voltage applied. If over 100 mils, there may be no bias at all.
> ( pair of 3-500 triodes)
>
> The higher the idling current, the easier it is to drive the
> triodes.
>
> 73,
>
> Mike
> W2AJI
>
>
> Sent from my iPhone
>
>
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