Well, I thought this thing was tuned up, but obviously something is wrong. These are a set of the 2x2x4" cavities... have a plunger in the front, and a variable cap adjustment on the back. Also, a pair of BNC connectors on the capacitor side.
The plate says Duplexer Vari-Notch, 147-174 It also implies that the TX has a 1.5dB insertion loss, but darned if I can get only about 4.5. I've talked to the guys at TX/RX, and they are looking for a book on them, but nothing yet. Anybody have any tuning instructions/info on them? The plunger is marked 'pass low', and the cap is reject high. Pretty much self explanatory, and they tune ok, but the insertion loss is higher than it appears it should be. Thanks, Tim
