[Amps] 3-500Z tube problems

[Vic Rosenthal 4X6GP]

Nothing's new under the sun.

73,
Vic, 4X6GP
Rehovot, Israel
Formerly K2VCO
http://www.qsl.net/k2vco/

On 13 Jun 2016 22:00, Bryan Swadener via Amps wrote:
> Vic,
>
> 1986 to 1989. See http://lists.contesting.com/_amps/2014-04/msg00255.html.
> Someone with the callsign "K2VCO" asked that question. Maybe you know him? ;-)
> vy 73,
> Bryan WA7PRC
>   
>       Date: Mon, 13 Jun 2016
> From: Vic 4X6GP
> Subject: Re: [Amps] 3-500Z tube problems
> .
> I have seen a few of these in genuine Eimacs from a specific period. I don't recall the date codes, but I'm sure someone here knows. The problem was bad welds which allowed the grid assembly to move and touch the filament.
>
> In the cases that I had, the short only appeared when the filament was hot. I doubt that this could be cleared by an electrical procedure, but maybe a slap on the tube in the right place would work, at least temporarily.