These days searching for a PDF manual on Google can lead you to some very sketchy sites that do not have the manual you want. It has become nearly useless to use Google for manual searches, and risky as well. I have not seen a PRO-2036 pdf manual on the web.
A few years ago before Radio Shack went under they had a support site with manuals for many of their scanners. For some scanners there was only a series of text files that did replicate the text in the actual manual minus the graphics. The PRO-2036 is one of those units that had only text-file documentation on the Radio Shack support site. The PRO-2036 text file is attached.
Another avenue to get a manual is to note that the PRO-2036 and BC890XLT scanners are twins. The BC890XLT pdf manual can be found at mods.dk.
In the June 1995 issue of Monitoring Times Bob Parnass reviewed and compared the PRO-2036 and BC890XLT. This is recommended reading for owners of those scanners.