In digging through my old notes I found a paper that looked like it would be a big help. Unfortunately it was in Italian and I do not speak enough Italian to read something that complex.
So I had put it aside for "future use". Last night I dug into it again and began the process of converting it to English. First I used a Linux command line program to extract the text from the posted PDF. Then I used another program to convert the PDF into an ODT (LibreOffice Text - open standard equivalent to MSWord).
By cutting reasonable chunks of the text file and pasting them into Google Translate, I got their English equivalent. Then I pasted each in the ODT file replacing the corresponding Italian. It is amazing how far Google's machine translation has progressed. There were only a few places where it "got lost" and I had to do a manual correction. But a lot of those rough spots were technical and easy to fix, while the rest were close enough to Spanish that I could figure out what the translation should be.
I am now the proud holder of "Tecniche di condizionamento del segnale per la Spettrometria Gamma" by Livio Cicala, but in English. The title in English becomes "Techniclal Signal Conditioning for Gamma Spectrometry". Sig. Cicala has done great work on the output from the PMT and I will have very little, if anything, to do in that section of the system.
I recommend you check out his site: http://www.theremino.com/en/blog/gamma-spectrometry