At 2/25/2007 12:04, you wrote: >Has anyone narrowbanded a Mitrek, MastrII, or Johnson PPL6060 with >Com-Spec's narrowband filter kits? Is it really worth doing?
I retrofitted a VHF HB Mastr II with the ComSpec filters a while back. They definitely work. However, if your goal is to provide additional adjacent channel rejection at 15 kHz channel spacing for 2 meters, the entire retrofit may actually be too much, as 5 kHz deviated signals will be distorted (up to 4 kHz seems to be OK). In that case you can try installing only part of the kit & carefully tune the IF to get the response symmetrical. I tried this part way through the retrofit & it seemed to work but didn't leave the receiver in that state for more thorough testing. Bob NO6B
