Morris, I'm not even to ask why "the actual installation is in the county jail in a jail cell". I'll bet that's an actual story onto its self.
I had an SCR2000A when I started in the ham repeater hobby, but soon realized that it was quite inferior. When I had it, I also re-wired the power supply, as you have, and the machine just sat there and ran. No issues. As far as the receiver goes, well, it's a stretch. It's not mother MOTO or GE, but it gets the job done. I finally got rid of it and acquired a MICOR with a unified chassis. Best money I've ever spent. Worth every dollar. Good luck on getting the system up and running. 73, Don, KD9PT ----- Original Message ----- From: "Morris Dillingham" <mdi...@nnwifi.com> To: <k1ike_m...@snet.net>; <la...@n7fm.com> Cc: <Repeater-Builder@yahoogroups.com> Sent: Friday, March 13, 2009 6:55 PM Subject: [Repeater-Builder] SCR-200(A) > Well, guys, I promised to follow up with the results of my attempt to > repair > the old Spectrum 1000 with the later model receiver. Thanks to Larry and > Joe, I have determined that my receiver is not an SCR200A but probably a > later model of the SCR-200. I obtained at least three versions of the > schematic from this series receiver thanks to these two gentlemen. Of > utmost importance was finding out the transistor part number since my > schematic was the wrong version. I was able to replace the front RF amp > and get the receiver working again. Before doing that, however, I noted > the > inadequate wiring, IMHO, in the power supply. The SCR-1000 upgraded PS > has > plenty of safety factor designed in as far as series pass transistors, > etc. > but the size of the wires was amazingly small. I completely rewired the > high current circuits to match the rest of the design. I am wondering if > during the period of this antique repeater there was a shortage of copper > and the price was high. After rewiring, the power output of the > transmitter > was noticeably increased to about 78 watts while it's specified as a 70 > watt > PA. I took the repeater to a staging area where we had another duplexer > to > test it on the air. (The actual installation is in the county jail in a > jail cell) Distant signals would develop a COR but there was no audio > when > using the duplexer. When the antenna is directly attached to the receiver > with the transmitter on dummy load, it works fine. At this point we were > too tired to go further so will get back on it again soon. I suppose the > front end may need touching up with that duplexer which has been checked > out > on another setup. > Thanks again to Joe, Larry and the list for their excellent help. > > 73 de > Morris KI4IUA > > > > > > ------------------------------------ > > > > Yahoo! Groups Links > > > >
