I'm having a problem with my pro-668 (legacy upgraded to ws1080) during the limit search. Every frequency that it detects is exactly .003125 too high. For example, on a known frequency of 461.9125, it will stop on 461.915625 every time. Is there any way to adjust for that variation so it stops on the true frequency? My TRX-1 with the exact same settings stop on the correct frequency. I'm guessing that the zeromatic function of the 668 is not working right and might have to be tuned, but I have no idea what the 3 fields are. They are all set to defaults, Threshold=1180, Slope=520, Delay=50. Can someone give me a "detailed" description of what each one does so I can have a better understanding of what they do? Any help or suggestions on what to try would be appreciated. Thanks.