Jim, I agree with you. Going to UHF for the repeater greatly simplifies things and UHF pairs are often much easier to find.
Also, one reason 145.25 might be open is it is the cable channel video carrier freq. Tune in many areas and you get a constant usually pretty strong signal. Tone is usually required by the repeater and users, but still a distant user might have problems hearing the repeater due to the cable signal. Here where I live we have 2 cable networks. Verizon is totally fiber and Bright House is fiber into the neighbor to a box about every 10th house and analog and digital cable on coax to the home. 145.25 is loud and clear. When Bright House goes full fiber, which will be a long ways off, then 145.25 will be free for at least in my area. Also if packet on VHF and repeater on UHF a simple crossband coupler and dual-band antenna will simplify things. 73, ron, n9ee/r >From: Jim <[EMAIL PROTECTED]> >Date: 2007/10/24 Wed AM 09:17:56 CDT >To: [email protected] >Subject: Re: [Repeater-Builder] Re: duplexer isolation and reciever noise >budget > > >>> OK - Here are my requirements for the transmit chain. minimal >>> physical space and minimal insertion loss :-) (ok - too >>> bloody obvious) Tuning simplicity is also a factor. I'm >>> combining 3 transmitters at 144.39, 145.05 +/- 0.04 and 145.25 ><snip> >>> Can you list out some of the other options that I might be >>> able to squeeze onto my trailer ?? > >You're trying to do all this in a trailer????? >Forget it, put up separate antennas for each radio and live with the >desense. >Not unless you feel like spending 10's of thousands of $$$$$$$$$. > >Went back and looked again, the 145.25 is to be a REPEATER??? Dude, hang >it up. Put the repeater on UHF and be done with it. Anything else is >ASKING for trouble. And put the other two on separate antennas and live >with it. You'll spend thousands of dollars and hundreds of hours making >this work and *KEEPING* it working! > >> I've run into some hitches getting a UHF backyard pair, or I would move the >> repeater to UHF in a heartbeat -- already have the duplexer for that, and >> that would leave me with a pretty standard BP/BP duplexer setup to separate >> the simplex radios, and would additionally get me back on a single antenna. > >Hogwash. 2M is FAR tougher to get a pair on then UHF. Unless you live in >one of the areas that UHF is getting taken out by mil radar, I guarantee >there is a pair available on UHF somewhere. In the *REALLY* strange >event there isn't, I GUARANTEE there is no pairs on 2M either. > >Find something like, oh, say, 444.0125 for instance, something where >there isn't a nearby repeater on either side, keep the deviation down to >+/-4KHz max, and you'll be fine. >-- >Jim Barbour >WD8CHL > > Ron Wright, N9EE 727-376-6575 MICRO COMPUTER CONCEPTS Owner 146.64 repeater Tampa Bay, FL No tone, all are welcome.
