Fw: [Collins] KWM2A repair question

Sandy and Kees Talen [email protected]
Fri, 7 Jun 2002 17:06:14 -0500


OK ....... SCREEN grid secondary emission of electrons caused by long
term bombardment by 
electrons headed to the plate. I realize that any material being
bombarded with electrons will 
have some tendency toward secondary emissions, including the screen grid
and the plate. But, 
because of the high potential of the screen and plate, electrons would
have a difficult time going 
anywhere. Only if you remove power could anything happen and then only
for a short period
of time. Guess that's what the conversation was all about.

But still, I would think, that only tubes which have been in service for
a while and have heavily 
bombarded screen grids would have a potential problem with this, so you
are probably talking 
about "older" tubes anyway. OR tube physical design may have some effect
(one brand has less
of a problem than another).

Comments ?

73s  Kees K5BCQ


--------- Forwarded message ----------
From: "Rolynn Prechtl   K7DFW" <[email protected]>
To: "Collins2 LIST" <[email protected]>
Date: Fri, 7 Jun 2002 13:26:45 -0700
Subject: [Collins] KWM2A repair question
Message-ID: <002101c20e61$a56e96e0$2b4c3ace@pygora>
References: <[email protected]>




> Yep, but they both (gas/grid emission) create unwanted electron flow
and
> effect the tube in the same way ... causes the grid to go
> more positive and effects the grid bias level.
.

This refers to gas/(control)grid emission.

The problem at hand is screen grid emission and an entirely different
animal.

K7DFW

..._._


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