______________________________ Reply Separator
_________________________________
Subject: Re: CRT decay
Author: classiccmp_at_u.washington.edu at internet
Date: 11/2/98 11:04 AM
At 05:59 PM 11/1/98 -0600, Doug Yowza wrote:
>
>No, I'm not sure. When I first saw it, I thought mold was growing along
>the edges, but closer examination showed that that "growth" was inside the
>glass, and the patterns were somewhat crystaline. I'll let you know if
>it spontaneously implodes.
Is it possible that you're seeing some element that's been vaporized
and is now being re-deposited as crystalline material? There is so
much going on inside a tube with high voltage, heaters, glowing wires,
etc. that something could be vaporizing and cooling.
>>Which reminds me of something I'd do as a kid: pop open vacuum tubes
>>and add water to the grey material tucked inside the rings, which
>>would then fizz. Maybe it was calcium carbide. I imagine it was
>>there to suck up water or gas after the tube had been sealed.
Sounds like you may be talking about a 'getter' which is used in the
production of vacuum tubes (valves for you gents across the pond) to
eliminate vapor and residual air the vacuum pump can't draw out or may
be in the metal components of the tube (plate, grid, filiment and
arbor). The getter is a compound (barium, magnesium, etc.) placed in
the tube which is ignited after the envelope is sealed. After the
getter ignites it sometimes leaves a silver coating inside the tube.
Marty
- John
------ Message Header Follows ------
Received: from lists4.u.washington.edu by smtp.itgonline.com
(PostalUnion/SMTP(tm) v2.1.9i(b5) for Windows NT(tm))
id AA-1998Nov02.110438.1767.74634; Mon, 02 Nov 1998 11:04:38 -0500
Received: from host (lists.u.washington.edu [140.142.56.13])
by lists4.u.washington.edu (8.8.4+UW97.07/8.8.4+UW98.06) with SMTP
id IAA17186; Mon, 2 Nov 1998 08:02:22 -0800
Received: from mxu4.u.washington.edu (mxu4.u.washington.edu [140.142.33.8])
by lists.u.washington.edu (8.8.4+UW97.07/8.8.4+UW98.06) with ESMTP
id IAA52748 for <classiccmp_at_lists.u.washington.edu>; Mon, 2 Nov 1998
08:02:08 -0800
Received: from threedee.com (threedee.com [208.18.183.65])
by mxu4.u.washington.edu (8.9.1+UW98.09/8.9.1+UW98.09) with ESMTP id IAA04
686
for <classiccmp_at_u.washington.edu>; Mon, 2 Nov 1998 08:02:06 -0800
Received: from winnie (winnie [192.198.5.13]) by threedee.com (8.7.5/8.7.3)
with SMTP id LAA00868 for <classiccmp_at_u.washington.edu>; Mon, 2 Nov 1998
11:05:22 -0600
Message-Id: <3.0.5.32.19981102092720.00ef98b0_at_pc>
Date: Mon, 02 Nov 1998 09:27:20 -0600
Reply-To: classiccmp_at_u.washington.edu
Sender: CLASSICCMP-owner_at_u.washington.edu
Precedence: bulk
From: John Foust <jfoust_at_threedee.com>
To: "Discussion re-collecting of classic computers"
<classiccmp_at_u.washington.edu>
Subject: Re: CRT decay
In-Reply-To: <Pine.LNX.3.95.981101175237.508K-100000_at_behemoth.host4u.net
>
References: <m0za2RV-000IyNC_at_p850ug1>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
X-Sender: jfoust_at_pc (Unverified)
X-Listprocessor-Version: 8.1 beta -- ListProcessor(tm) by CREN
Received on Mon Nov 02 1998 - 10:41:00 GMT