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Re: X-rays from light bulbs/Tesla Coils
Jim
I never said the x-ray hazard was from the picture tube in the old sets.
Picture tubes were and are engineered so they won't be an x-ray hazard under
NORMAL operating conditions as I stated. I believe the technology in CRT
design and materials have progressed a bit since the 40s and 50s and old
picture tubes would be better canidates if one wanted to try to get x-rays
out of one . I know the government standards are more strict on modern ones.
(regulations never get less strict). Yes, you had a much greater x-ray
hazard from the rectifier tube, I don't disagree. X-rays are produced in
the CRT itself if it is improperly manufactured or if the hi-voltage on the
anode is excessive, and the CRTs from the 40s and early 50s were worse. The
CRT manufacturing industry of which I am a small part is required to test
CRTs for X-rays, the standards are higher now. (or is it just another stupid
government regulation and there really is no potential hazard at all?) TVs
don't have rectifier tubes anymore, but we are still required to test the
CRT periodically, WHY? We have had CRTs fail for excessive x-radiation in
house within the recent past because of some bad glass so I know they are
capable of producing x-rays. I've worked in the CRT manufacturing business
for 26 years, I may not be a design engineer or a Phd. but I do know
something about picture tubes and how they were and are manufactured and
tested. The original poster wanted to know IF a crt COULD be made to
produce X-rays, not, if a TV or computer monitor as a unit operating under
normal conditions makes x-rays or if other circuits in the set would produce
x-rays. The answer was and still is, YES, a CRT can under the right
conditions, I stated one of those potential conditions, and the old black
and white CRTs from the 40s and early 50s which contain no shadow mask,
different glass, different phospher material, inferior outdated designs and
sloppier manufacturing techniques WILL be better than modern day color
displays for producing x-rays under the ABNORMAL conditions I stated
earlier, but they will not under NORMAL operating conditions be any worse
than a modern tube (which produces next to none). Now, wether or not either
could be made to produce strong enough x-rays to make a GOOD radiograph I
don't know or care, but a CRT can definitly be made to produce x-rays. .
Mike KB9NZQ
----- Original Message ----- From: Tesla List <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Saturday, September 11, 1999 4:20 PM
Subject: Re: X-rays from light bulbs/Tesla Coils
> Original Poster: "Jim Lux" <jimlux-at-jpl.nasa.gov>
>
> And, the xray hazard from old color TV's wasn't from the picture tube, but
> was from the HV rectifier in the 2nd Anode power supply. These tubes are
> available in two forms (with the same part number, of course) one with a
> lead glass envelope, the other not. Apparently, they are distinguishable
by
> their weight. I seem to recall an article in "the Bell Jar"
> (http://www.tiac-dot-net/users/shansen/belljar/ ) talked about it, and had
some
> radiographs.
>
> ----------