[ARC5] OD3 VR Tube

[Sandy]

I remember two incidents involving gas filled devices that stay in my 
memory.

First is the ARC-27 Collins built aircraft UHF radio.  There was some NE2 
type neon lamps across several relays in the set as I recall that were 
suppressors for the "inductive pulse" that happens across the armature coil 
when it is de-energized.  (In those days using silicon diodes for this 
purpose was unknown!)  A couple of times I remember our "Shop expert" on the 
ARC-27 was stuck with sets that worked "OK" when the outer housing was 
removed but had glitches when the housing was replaced and pressurized!  It 
turned out to be the "Photosensitivity" of certain of the neon lamps in the 
set.  As "Jimmy Hunt" said about the problem: "The damned lamps are scared 
of the dark!"


The second case involved a "Mobile telephone decoder" which decoded the 
assigned telephone number of the VHF FM mobile telephone and rang a 
bell/buzzer when that set had an incoming telephone call.  Ma Bell used a 
mechanical device to do that job with the Motorola radios, but CMC (Canadian 
Marconi Company) designed an electronic device to do the same job that was 
more compact and had no moving parts.  The decoder used cold cathode triode 
subminiature tubes.  In order to do away with the "photoelectric" effect, 
again, NE-2 type neon bulbs were illuminating the tubes in order that they 
worked properly in darkness of an automobile trunk and the housing for the 
decoder.  These exhibited some very weird operation when the neon lamps 
failed at times!  Not always this happened, but enough times to drive you 
nuts until you got the dim or non working neon lamps replaced inside the 
decoder!

That's my "gas filled devices" in the dark story.  Maybe the old "VR" tube 
regulators sometime do the same thing in the dark?  I never had any trouble, 
but then maybe I was always lucky?

73,

Sandy W5TVW
-----Original Message----- 
From: John Hutchins
Sent: Friday, November 09, 2012 9:14 AM
To: arc5 at mailman.qth.net
Subject: Re: [ARC5] OD3 VR Tube

All -

"--> For one thing, VR-tubes must be able to have some input from light to
"encourage" the formation of the internal "plasma" "  <---  What that's a 
new one?

Lighter side:
So the question is: Does a VR tube work in the dark, completely shielded 
from any form of radiation ?
Similar to : does a tree falling in the forest make a sound....

Hutch




On 11/8/2012 3:06 PM, Kenneth G. Gordon wrote:
> For one thing, VR-tubes must be able to have some input from light to
> "encourage" the formation of the internal "plasma"

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