I thought I would add that I am still working on this 1.2 GHz duplexer project.
I removed the original plungers and cut 1/2" off of the outer shell, then sawed the slots down another 1/2".
The cans now tune up past 1.3 GHz.
Now I am trying to work out the correct coax lengths to align the notches and get the insertion loss down.
I am using coax during the trial and error part (mostly error) but will replace with 1/4" hardline when I have the electrical lengths resolved.
Rex AJ4GC
