If memory serves, that radio is old enough to be a wideband rig (+/- 15 KHz FM deviation). You can turn down the XMTR FM dev to +/- 5 KHz, but your receiver's bandwidth is more complex to narrow it down to +/- 5 KHz. As it is now, you're nowhere near filling up its RCV bandwidth, so the remaining RCVR bandwidth lets noise through. There used to be some parts around that you could replace in the RCVR to narrowband (+/- 5 KHz), but I suspect they'd be nearly impossible to find now. You might be better off digging up a more modern RCVR and using it.
73, Dick ----- Original Message ----- From: "rod_shaner" <[EMAIL PROTECTED]> To: <[email protected]> Sent: 17 February, 2007 11:29 Subject: [Repeater-Builder] 1953 Motorola BaseRadio for 6meters > Hi all, > I'm seeking schematics, manuals, and advice on peaking a working > unit. Its model number is FSTR520BR(FW)1ASP2. Just tearing that model > number apart is a workload! > It was a commercial base radio, and it's crystalled for 52.525 FM. > Right now I'm trying to get as much as possible out of the receiver. > It works, but 25 mile away 40W signal radiated through a vertical > antenna is just out of the noise on this end. My receive antenna's > base is 30 inches off the ground for test purposes. > > Advice is requested. > > Thanks.
