RE: spark gap x-rays !

Hi All on list,
                 I know this thread died a while ago but I just thought I
would mention that I looked into the possible X-Ray output from my coil some
time ago.
I borrowed one of the Universities Geiger counters and pointed it at my 800W
The coil was within a Faraday cage of chicken wire and producing 2-3 ft of
arc at the time.
I was horrified to find that the counter instantly registered nearly 100
counts per second!
Common sense prevailed when I realised that the high order harmonics leaking
through the cage were hitting the counter's electronics, and giving an
erroneous reading (thinks..100 counts= 2x 50Hz......thinks... spark gap RF!)

I then tried X-Ray film badges all over the place, including one on the
I also got brave, and put one next to a 100watt 240v bulb on the top of the

Guess what.. They all came back from the NRPB lab negative!
No detectable X-Rays.

Run times were no longer than 3 minutes BTW, but I did do at least 4 runs on
each badge.

I'm not sure what results I would have got with a longer exposure or a
bigger coil, but I thought I would throw that data in for what it's worth.

        Regards  Martin Dale  TCBON

> ----------
> From: 	Tesla List[SMTP:tesla-at-pupman-dot-com]
> Sent: 	Tuesday, January 05, 1999 6:54PM
> To: 	tesla-at-pupman-dot-com
> Subject: 	Re: spark gap x-rays !
> Original Poster: Hollmike-at-aol-dot-com 
> In a message dated 1/5/99 2:43:43 AM Mountain Standard Time,
> tesla-at-pupman-dot-com
> writes:
> > 
> >  I wouldn't trust any electronic measuring device such as a geiger
> >  counter close to a TC - a film badge would be much more appropriate
> >  
> Not a bad idea.  It reminds me of a time when one of my coworkers
> accidentally
> left his TLD badge next to his computer monitor.  Caused a bit of a stir
> when
> it was developed.  Should work for checking out a gap.