Al Shinn wrote -
(snipped..)
> I don't know now where to get a bare silicon photo diode any more but
> this approach would be some $1000 less then some previous pointers -
> maybe < $20. Even Geiger counters can be in the $150 Or less range
> http://www.blackcatsystems.com/GM/geiger_counter.html
> Geiger Counter Nuclear Radiation Detector Alpha Beta Gamma X-Ray
>
> Looking forward,
> Al Shinn
>


I used to make very basic phototransistors by cutting the top of the
can off the metal versions of the BC108/2N2222 types etc. (In general
I would then add clear epoxy for moisture protection). It may be worth
a try if you have any old metal can TO-92 bipolars lying around.

(Prior to that I had made them by scraping the paint off the old OC70
(?) Ge. bipolar parts. - but that's showing my age I think)

RP
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