At 02:20 PM 11/06/07, you wrote: >Keith, KB7M wrote: > > I've built several repeaters over the years, but only for the 2m and 70cm > > bands. > > > > In a moment of insanity, I purchased a Wacom 222Mhz duplexer and now I > > realize that 222 Mhz radios suitable for repeater operation are not readily > > available. :-( > > > > I see that folks have documented methods for converting VHF high band MASTR > > II and Micor radios for 222 Mhz. Unfortunately, I don't have either radio > > in my stash of radios. I DO have some VHF Mitreks, some UHF > Micors, and one > > VHF MASTR Executive II radio. Can any of these be converted to 222 Mhz? > > Does anyone have an already converted radio that they would be willing to > > trade for something? I know that the repeater-builder guys have already > > converted radios forsale, but I'd like to find a way to do it for less than > > the $700 that they want for them if I can. > > > >The ExecII should be pretty close to the MII, I would think. > >Don't spend good money on the made-for-ham boxes. First, they're more >expensive then the RB conversions, and they WON'T work as well. > >I think I've heard of people converting Mitreks too, although like most, >the PA's don't go.
I've seen two Mitreks transmitters that were converted. In both cases they started with radios that had blown up PA decks, stripped them and put down 220 power modules. One was a UHF and the conversion removed the last doubler from the exciter and the following tuned circuits tweaked to compensate. The dev pot was cranked up to compensate for the missing doubler. The existing 440 receiver was used as a control receiver. The 220 receiver was a converted Micor in a Spectra-Tac chassis. The conversion of the high band transmitter was different - the 75mhz to 150mhz doubler was converted into a tripler and the following tuned circuits tweaked to compensate. The receiver conversion was similar - triple instead of double in the LO chain. I have no idea what he did for a front end. If anybody wants to do a 220 Mitrek conversion article I'll make room for it on the Mitrek page.
