Thanks, Don, for the story about your SCR-200A. Sounds like the PS wiring was a common issue at the time.
The local club was able to get space on the county sheriff's tower. The repeater went into a jail cell which appears to be the solitary confinement one. It sits on the steel bunk along with an FBI repeater. We have a weekly "Jailhouse Net" or will have again when operational. 73 de Morris KI4IUA > -----Original Message----- > From: [email protected] [mailto:Repeater- > [email protected]] On Behalf Of Don Kupferschmidt > Sent: Friday, March 13, 2009 8:57 PM > To: [email protected] > Subject: Re: [Repeater-Builder] SCR-200(A) > > 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" <[email protected]> > To: <[email protected]>; <[email protected]> > Cc: <[email protected]> > 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 > > > > > > > > > > > > ------------------------------------ > > > > Yahoo! Groups Links > > >
