Hi Jim, You could run a few in-detail tests to ensure the receiver IF Bandwidth looks normal, but I'd try the obvious first.
A complete receiver realignment using the Service Manual Steps, which include pre-setting the inductor cores to the charts shown in the book... aka not a re-tweak peak alignment from an nearby frequency. The manual also describes how to check and properly set the discriminator coil. Set the channel element Frequency by looking at the injection frequency (using rf leakage) on the receiver board. It will by the Frequency of operation offset high or low the IF value. Crank the PA way down to about 60-75 watts max output unless you don't use it much. Use a good service monitor with an adjustable tracking generator to set up the duplexer. Check the band-reject notches for proper placement and adjust them if they're off. If there is nothing mechanically or electronically wrong with the repeater, I would suspect and test both the receiver and duplexer alignment. Expect the properly aligned MSR UHF Duplexer to output about 45-50 watts when you put in about 60 to 65 watts from the PA. cheers, skipp > "Jim Miller WB5OXQ in Waco" <[EMAIL PROTECTED]> wrote: > > I have a uhf msr2000 which I recently changed frequency to 464.075/469.075. Original freq was about 1.5mhz away. I sent the elements in and had them re-crystaled. After I installed them and tuned up the receiver it worked pretty well for a month. I noticed it loosing sensitivity lately so I got out the service monitor to check sensitivity. Here is the problem. If you tune the frequency trimmer for best quieting you get very scratchy audio. If you tune for best audio you loose sensitivity. I did not bother the discriminator coil but if it is misaligned will that be my problem? If aligned for best quieting it breaks squelch at around .21uv but at best audio recovery it only makes .8uv. This is with the generator passing through the duplexer with the transmitter disabled. The duplexer is factory Motorola. This is a 110 watt intermittent duty repeater and I am getting 65 watts out of the duplexer. Does this sound about right for this machine? > WB5OXQ >
