Yes, we tuned a Celwave 6 can mobile UHF duplexer to 100 db using an IFR and and a return loss bridge. It's the best one I've seen, as most are in the 75 to 85 db range.
When Telewave recently retuned our 6 can full sized 2 meter duplexer for our new 400 kHz split, they were happy to hear that it was a digital system and the deepest and narrowest notches could be used to achieve maximum notch. Ernie W6KAP
