[Dave xxxx]

Not sure if any of the tube experts can help, but I am interested in knowing
the radiation output of an early 10 inch CRT tube ?

I know the thick glass front would cut radiation exposure, but the one I am
thinking of had 8 layers of panels on the side to cut exposure.


ta in advance



--
Dave xxxxx

www.davewhitter.myby.co.uk

[Phil Allison]

"Dave xxxx"

Not sure if any of the tube experts can help, but I am interested in
knowing the radiation output of an early 10 inch CRT tube ?


** Colour or monochrome ?


I know the thick glass front would cut radiation exposure, but the one I
am thinking of had 8 layers of panels on the side to cut exposure.


** You need to explain that a lot better.



....... Phil

[Dave xxxx]

Phil Allison wrote:

** Colour or monochrome ?



** You need to explain that a lot better.



...... Phil

monochrome

this machine http://www.egoltronics.com/sp1070c.html

uses B&W crt which is at the bottom screen aimed up

as the machine is made for 110 volts I used a step up transformer

this would often trip the internal power supply on switch on

so its used with front lower panels removed

as was at times most of the shields around the crt tube

if your in front of a crt tube the thick glass front cuts down radiation

if your by the side of the machine the crt screen is facing upwards
so with side panel and most of the protection screens removed the amount of
radiation getting to you must be higher ? ( I think)

sorry if explanation not too clear but brain lesions makes thinking hard lol

[Phil Allison]

"Dave xxxx"

monochrome

this machine http://www.egoltronics.com/sp1070c.html

uses B&W crt which is at the bottom screen aimed up

as the machine is made for 110 volts I used a step up transformer

this would often trip the internal power supply on switch on

so its used with front lower panels removed

as was at times most of the shields around the crt tube

if your in front of a crt tube the thick glass front cuts down radiation

if your by the side of the machine the crt screen is facing upwards
so with side panel and most of the protection screens removed the amount
of radiation getting to you must be higher ? ( I think)


** I doubt there are any significant X-rays with a monochrome CRT.

The shielding you allude to is likely against interfering magnetic fields
blurring the images.

Unless it was all made of lead sheet ?




........ Phil

[Arny Krueger]

"Dave xxxx" wrote in message


Not sure if any of the tube experts can help, but I am
interested in knowing the radiation output of an early 10
inch CRT tube ?

X-Ray radiation of CRTs mostly has to do with the max HV applied, not
directly the size.

[robert casey]

X-Ray radiation of CRTs mostly has to do with the max HV applied, not
directly the size.




Back about 30 years ago I worked at some small company that built
devices that transferred video from CAT scanners to hard copy on X ray
film. Little more than a box with a CRT monitor inside. We were doing
a custom job for a customer who wanted it to run at 480p instead of
480i, using a modified Conrac B&W monitor. We changed the CRT to a
smaller but higher resolution 5 inch flat screen. But we didn't want to
spend money to change the high voltage supply. My lead engineer said
"The excessive high voltage won't hurt the tube, it makes for smaller
spot size and a sharper image, and it will be inside this steel box so X
rays are not much of an issue".... Okay. The high voltage was about
30% too high.

[Ian Iveson]

robert casey wrote

Back about 30 years ago I worked at some small company that built
devices that transferred video from CAT scanners to hard copy on X
ray film. Little more than a box with a CRT monitor inside. We
were doing a custom job for a customer who wanted it to run at 480p
instead of 480i, using a modified Conrac B&W monitor. We changed
the CRT to a smaller but higher resolution 5 inch flat screen. But
we didn't want to spend money to change the high voltage supply. My
lead engineer said "The excessive high voltage won't hurt the tube,
it makes for smaller spot size and a sharper image, and it will be
inside this steel box so X rays are not much of an issue".... Okay.
The high voltage was about 30% too high.

Why x-ray film? Is x-ray film only sensitive to x-rays?

I thought x-rays would be at 90 degrees to the angle of the electron
beam?

Ian

[Phil Allison]

"Ian Iveson"
robert casey wrote

Back about 30 years ago I worked at some small company that built devices
that transferred video from CAT scanners to hard copy on X ray film.

Why x-ray film?


** Just describes the usual use of such sheets of negative film.

Standard size, medicos are familiar with it etc.


Is x-ray film only sensitive to x-rays?


** No - it is sensitive to visible light, it is normal film.



....... Phil

[Dave xxxx]

Dave xxxx wrote:
Not sure if any of the tube experts can help, but I am interested in
knowing the radiation output of an early 10 inch CRT tube ?

I know the thick glass front would cut radiation exposure, but the
one I am thinking of had 8 layers of panels on the side to cut
exposure.

ta in advance



thanks for all the answers

[Arny Krueger]

"robert casey" wrote in message
k.net

X-Ray radiation of CRTs mostly has to do with the max
HV applied, not directly the size.

Back about 30 years ago I worked at some small company
that built devices that transferred video from CAT
scanners to hard copy on X ray film. Little more than a
box with a CRT monitor inside. We were doing a custom
job for a customer who wanted it to run at 480p instead
of 480i, using a modified Conrac B&W monitor. We changed
the CRT to a smaller but higher resolution 5 inch flat
screen. But we didn't want to spend money to change the
high voltage supply. My lead engineer said "The
excessive high voltage won't hurt the tube, it makes for
smaller spot size and a sharper image, and it will be
inside this steel box so X rays are not much of an
issue".... Okay. The high voltage was about 30% too
high.

The problem is not "too high", it is related to the actual voltage. My
recollection is that X-ray generation isn't a problem up to 10-15 KV, but
can be a problem at 30 Kv and up.

This article is instructive. It seems to say that one can generate useful
amounts of x-rays with some TV-type high voltage rectifier tubes if you
apply about 40 Kv, and several dozen milliamps.

http://www.belljar.net/xray.htm

The wikipedia article is interesting, but has less practical value:
http://en.wikipedia.org/wiki/X-ray_tube