On Wed, 08 Aug 2007 13:29:00 +0100, Nick Gorham
wrote:

Don Pearce wrote:
On Wed, 08 Aug 2007 12:38:47 +0100, Nick Gorham
wrote:


Phil Allison wrote:

"Don Pearce Posturing Pommy Turd "


tony sayer



In my earliest work days I designed colour TVs. We had an X-Ray
detector permanently covering the bench, because if the line output
valve got a few too many volts, and a bit too much current, its anode
would start to glow red, and X-Rays would come flooding out.

Wasn't that the shunt stabiliser that did that?.

Hence the metal can in some sets?..

No, definitely the line output valve.




** Another absolute BLOODY LIE !!

Only tubes supplied with 16 kV or more are at all involved in x-ray
generation.





......... Phil




I couldn't remember just what the voltage was, but I was sure its more
than 1kv.


Well, this chap is aware of the phenomenon too

http://www.penders.cwc.net/otltbeht.html


"The PD500 is also shielded. Not only does this valve dissipate 30 Watts
but it also emits X-Rays"

That will be the valve with its anode connected to the 25kv EHT line I
guess.

Here too

http://www.r-type.org/exhib/aah0027.htm


And that will be the valve with a max Va of 25kv

d


I am not suggesting that the valves mentioned can't produce x-rays, but
I am certain that a gm70 won't with 1kv on its anode.

Having just read that second link of mine, I find that Mullard called
the valve in question a line output valve, although it was used mainly
as an EHT stabilizer. 40 years have clearly fuddled my memory
slightly. I must ask nurse to tuck in my tartan blanket a bit tighter!

d

--
Pearce Consulting
http://www.pearce.uk.com