Thanks for the help, Josh! I've saved this email to reference when the time comes to do the work. From what I've seen, there are at least five different documents out on the web concerning the retuning of Micor's into the ham bands, but they all start with assumptions of a well-stocked test bench and some fairly good knowledge of the "geography" of the Micor systems. I'm hoping to compile everything that I can find together into a document that will act as more of a real project plan, from "parts and equipment needed" through buttoning everything down and putting it in operation. When/If I get it done, I'll be sure to put it in the files for this group.
Thanks again! Brian, WW9A Columbus, IN > >From: Josh <[email protected]> >To: [email protected] >Sent: Sun, May 30, 2010 12:03:28 AM >Subject: [Repeater-Builder] Re: Retuning a UHF Motorola Micor without a >deviation meter or signal generator ? > > > >Brian, >Here's what your project would look like. > >First, you'll need crystals. Those can be ordered. > >Second you'll need access to a 'test set' of sorts for the micor. There are >several types, this'll set you back $20 to $100 (depending what test set you >get). This is necessary to 'tune' the RX and TX on the unit to work with your >new crystals. > >Third, You've got filters to tune. The easiest way to do this is with a >spectrum analyzer and tracking generator. I just bought one for $1100 - there >are other, less accurate ways to do this, but I chose the 'buy the right tool >for the job' route. You really want to see whats going on. This same tool will >be required (or use other processes) to tune a duplexer so you can use a >common antenna for TX and RX. > >You'll be interfacing an external repeater controller (not difficult, although >I'm fighting a COS issue right now on my micor project) to give you a time out >timer, CW or voice ID'er, and the DTMF control you'll want (disabling the >repeater if it goes berzerk). I'm using the NHRC-2 , under $100 if you do it >as a kit. > >Micors are REALLY easy to work on and a lot of fun - I'm getting close to the >end of my project on one here, and I've learned a ton. > >If you don't have access to the tools, and dont have friends that do, there >are folks on the groups (this and others) that might be willing to 'tune >stuff' for you, so you can do all but a few parts yourself. > >Good luck with your project! > >Josh >--- In [email protected], Brian Smith <lirc1...@...> wrote: >> >> I will apologize in advance, as I am an extreme newby in the world of >> repeater building / operation. >> � >> We've been donated a UHF Motorola Micor system.� The system has >> documentation that shows that it once ran at 78W out in commercial service. >> � >> Being an amateur radio operator without a commercial or well-stocked test >> bench, I do not have ready access to a deviation meter or signal generator. >> Is it possible to retune these things down to the amateur radio 440 band >> without these two pieces of test equipment? >> How likely is it that I will run into significant performance issues without >> these pieces of equipment? >> � >> Thanks! >> Brian, WW9A >> > > >
