At 4/11/2007 11:02 AM, you wrote: >Re: Poor Mans Repeater Project anyone? > >Would some of you group members be interested in a "Poor Mans >Repeater Project" as described below? > >The project goal would be to construct a simple repeater using >various/mixed radio parts. We as a group would talk about various >portions of the repeater during actual construction of a project >by at least one or two (probably more) group members.
I'm just starting on my 3rd GE MVP VHF portapeater. #1 is locked up in a tower; I guess that makes it a "permapeater" now. No regrets - it's still accessible & has on-off control via an open-drain output of a controller on a co-located 440 system, plus it was cheap: radio & mobile duplexer were free, IDer was an old Autocode board out of my junkbox, homebrew audio/keying circuit & used pre-existing GP9 antenna with crossband diplexer. Only thing I remember explicitly buying for the system was the crystals. #2 got pressed into standard 600 kHz repeater service (sans mobile duplexer, of course). Anyway, I started on #3 by grabbing a VHF MVP out of the garage & throwing in on the bench. I test before I do any converting so I don't waste time converting a dog. I pay particular attention to the TX, as RXs are easy to swap but if the RFPA has a problem it's easier to just use another chassis with a working RFPA. It tuned up fine: 32 W on 144.93, & 0.35 µV for 12 dB SINAD @ 147.585. One coil in the IF section was way off for some reason, but everything's playing fine now so time to start the conversion (convert to duplex & bring all needed I/O out the rear 10-pin system connector). I'll also be installing the VHF UHS preamp I bought from Kevin at the '05 Hamvention to see if it will handle the mobile duplexer isolation. I need to squeeze as much sensitivity as I can out of this one, even if it means adding an additional filter, sized within reason (not a 10" 1/4 wave Motorola bottle!). Bob NO6B
