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Re: [Amps] Powering NOS 8874's ?

Subject: Re: [Amps] Powering NOS 8874's ?
From: Steve Bookout <>
Date: Thu, 18 Aug 2022 14:46:47 -0400
List-post: <>
I assume others have answered you already.

If it were me, I would maybe leave the plate caps off and run it for a long day, with just the filaments and blower.  Just no plate voltage.  (but, Plate voltage is not a bad thing unless there is some internal problem with the tube anyway.)  I have heard many times over the years, metal/ceramic tubes with 'getter', or 'self-getter' with just the filaments running.  This burns off any impurities that may have been in the tubes from dis-use.

If it were a glass tube like 3-500's, you would need to run them with some plate voltage with the plates slightly red, in order to accomplish the same thing.  Glass tubes are intended to be run red at their full output, for the 'health' of the tube.

Metal/ceramic just do it differently

Steve NR4M

On 8/16/2022 11:05 AM, Steve London wrote:
I know this sort of question has been asked before, but I'll ask again in
case there are new insights.

I have acquired a NOS 8874 with a date code of 0208 (8th week of 2002 ?).
Never even been plugged into a socket.

Best way to power it up ?

Steve, N2IC
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