[Top] [All Lists]

Re: [Amps] 4-250a mounting

Subject: Re: [Amps] 4-250a mounting
From: R.Measures <>
Date: Sun, 25 Dec 2005 13:57:41 -0800
List-post: <>
On Dec 25, 2005, at 12:27 PM, Peter Chadwick wrote:

> As I understand it, the filament structure is the same as the 3-500Z.


> Not sure about filament to grid spacing,

I don't know the distance involved, but the filament to grid breakdown 
potential is typically 6000 to 8000 volts.

> but I have had some go grid to filament short when hot, and that's 
> with them mounted vertically. Depending how many tubes you have, it 
> could be worth trying. Rich Measures may have some historical 
> knowledge of 3-500 failure modes which could be applicable.

In my experiences, 3-500Zs typically fil--grid short at around the time 
that a big bang is heard.  Applying a short between the grid pin and a 
filament pin makes no sound.

> I think personally, I'd avoid it, but that's partially because I don't 
> have a lot of spares!

> 73
> Peter G3RZP
> _______________________________________________
> Amps mailing list

Richard L. Measures, AG6K, 805.386.3734.

Amps mailing list

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