Since you are not seeing a doubling of the notch depth with the two cavities in line, I suspect the cable length is incorrect as Eric pointed out.
You also mention the tuning caps seems a little flaky. They shouldn't. It may be that they have been lightning damaged, since that is a known issue with these cavities. Or it may be something else. Some of my notch caps were very flaky (on a DB4062, which is the 6 cavity version of the 4060). Disassembly and thorough cleaning cured the problem. There was "gunk" interfering with contact between the finger stock and the tuning plunger. I also disassembled all the coupling loop assemblies and cleaned all mating surfaces. The duplexer is working perfectly now, with the caps being very smooth and stable. I am also getting deeper notches than I had before. Paul N1BUG Joel Hall wrote: > Hope some of you guys that have some experince with db 4060 duplexer,the > pass is fine but the notch is the problem I can see the notch at around > 35db on my ifr 1600s per each can but when i combine them together about > 50db is the best i can get I have new cables made 1/4 wave long , the > tuning caps seem a little flakey may have had been hit with a lightning > surge. > I have not taken them apart yet so any thoughts? > > Thanks kj4si
