Gamma Spectrometry Forum

I was able to run the program and get what may be a plausible spectrum, with my first test of a surplus 3" R6233-02 PMT and 40mm x 40mm NaI scintillator, using a Theremino "PMTAudioAdaptor - New Version" circuit. This PMT is spec'd for 1kV bias voltage which is was I used initially, b...

> Honestly, I'd just ask him straightaway if he can assemble one for you and what that would cost. Thank you for the suggestion. The Theremino website looked a little bit 1990s style and I didn't know if the link was current or not. However Lello replied quickly to an email and was able to offer the...

https://www.tindie.com/stores/nuclearphoenix/ In case of interest, I did order the Open Gamma Detector board (the one with a Pi Pico board attached) from the above Tindie site, and it arrived yesterday. It seems to be working fine for me so far. I suppose they left the trimpots in some default midd...

> GammaSpectacular GS-Pro

I do see that the GS-PRO-V5 looks like a very good product. As my own spectroscopy interest is strictly a personal hobby, I was starting my hardware search at a lower price point.

Update: it appears a different, but similar board is in fact available from rhelectronics.store being titled
"usb-spectrometry-adapter-driver-for-hobby-gamma-spectroscopy-with-high-voltage-and-adc"

however for some reason it is limited to 900 V output, and does not reach 1 kV.

I'm curious if anything resembling the “PmtAudioAdapter – New version” board described at the theremino.com website under schematics#pmtaudioadapter is available assembled from any source? The page links to what may be a personal email address for "Lello" but I was wondering if there was s...

I'm a newcomer to the idea of using a soundcard as a MCA. I understand it apparently works and is a popular thing. On my scope, I see the pulses coming out of my PMT return to the baseline after only a few microseconds, apart from the very largest ones which might extend to say 10 or 15 microseconds...

Hi Matthias, Thanks for the quick response. Yes, I do agree with you any capacitor introduces pulse-rate-dependent distortion, because it forces average DC current to zero, and the pulses are unipolar with an average DC level proportional to both pulse rate and pulse amplitude. However for my curren...

To follow up my own last post, I added a coupling capacitor to block the DC path, just before the R17,R15,R4 divider ahead of U8 in the "SiPM Output and Preamp" block of OpenGamma Detector rev4.0 schematic, and there are now two copies of the 1k resistor R4 to ground, one on either side of...

First, thank you very much to NuclearPhoenix for publishing the Mini-Sid and Open Gamma Detector projects on github https://github.com/OpenGammaProject I build a copy of the Mini-Sid board shown there, and confirmed it worked as expected. I'm still waiting on my order of an OpenGammaProject PCB to c...