>If it were a notch-only duplexer, it would have two >reject freqs listed. A duplexer is used on two >discrete frequencies, so both should be present on any >label. A pass freq plus a reject freq indicates the >unit is doing both pass and notch. Still fine for one >half of a duplexer.
Well, it IS a notch only duplexer no matter how you look at it. Don't get hung up on a silly sticker. The thing has been retuned, simply, so the sticker does not apply to the tuning. I know quite well what a duplexer is, and it is certainly not a requirement to label both frequencies on every label. Often you find a label on each port (transmit and receive) with the respective pass (or notch) or both frequencies. As you can see by the cavities, there is only one port in use. One connection, with a coupling loop, and a coax T is a NOTCH. If ANY of the cans were bandpass, there would be TWO connections (coupling loops) and the coax would go in to one port and out the other. Please keep in mind that one can build a 'duplexer' out of 'cavities' and those cavities can be 'pass' or 'notch' or 'bandpass/bandreject'. Once these components are assembled with the correct intercavity cabling, you have created a duplexer (regardless of what the label says). 73 N7HQR
