Here's what I found by searching w/Google for "Astron RS-50 Schematic" Looks like the schematic is 2000 vintage but hopefully, it's the same or close for your older power supply. I "copied & pasted" this JPG into my image viewer program & then printed it on our laser.....I'll fax it to you if you can't get a good copy. http://www.repeater-builder.com/pix/rs50m.jpg 73, Lynn, K5AVJ