A few times over the last few years, a friend's UHF MSF 5000 has been found to be off-frequency by 5 KHz on receive.
We find this out, of course, because everyone sounds bad, and then one day we thought... hmm, that sounds 5 KHz off frequency... Repeater is on 449.625 TX, 444.625 RX. Sometimes it goes low -- we could transmit into it 5 KHz down from it's programmed receive frequency and sound fine. 444.620 Today it went high. I could talk through it beautifully on 444.630. Grounding at the site is basically as good as I've seen anywhere, power may be taking bumps from time to time, but we're not really hearing any controller resets or anything prior to these little "off-frequency" excursions by the Receiver... it just goes -- seemingly when it wants to. Plugging in the Moto test set seems to always reset the repeater so you can't diagnose anything digital unless you leave the test set plugged in all of the time (which isn't going to happen at this site). A reboot will clear the problem. Turn the power off, turn it back on, repeater's receiver locks and works correctly on-frequency. I forget since I'm not an "MSF guy" if it's the CXB or the CLB that is the firmware programmable model -- but that's what he's got. Firmware. This particular station also had a TX VCO lock problems, but that went away with the replacement of the "spring assembly" thing for the VCO. (Yeah, I don't know what to call that thing, but anyone who's worked on one knows about the locking mechanism for transporting them.) The controller and other boards have all been disconnected/reconnected (all connectors have been "cycled") and right now, we're stumped. Originally some thoughts about bad power or static discharge, but we're not exactly in "static/lightning" season out here right now, and the snow is heavy and wet for the most part. Plus it didn't do it all winter with precip static from snow, etc... static doesn't really make sense. The OTHER MSF took a lightning strike a while back, and its controller was fried -- so no spares available to swap parts at this point... would want a better idea of what to swap/try before paying for parts. Anyone ever seen this? Nate WY0X
