> Operating a 500K spacing duplexer at 600K is not a problem > but trying to get a 1M spaced duplexer to operate at > 600K will be. The issue is the way the individual > pass/notch filters interact with each other.
The issue is the "Q" and how the cavities with their included loops/probes are designed & constructed. The result of said is how the cavities ineract with each other. > As to your immediate problem, adding a pass can via > the proper length of coax on the RX side may help. If he's running a TPRD-1554 or TPRD-1454... he only needs to make sure the duplexer is properly setup & aligned... that his receiver and transmitter are of decent performance quality properly aligned & running a realistic tx power level. A close look at the receiver front-end design and it's realistic performance in duplex (repeater) operation would be high on the list of thing to do. Some receivers are just plain crappy... > I would suggest that you look for someone in your region with > the proper test equipment to sweep tune the equipment. ... add in the knowledge and experience to do the above task. > Also what type of repeater equipment are you using? ... well worth knowing before pointing a finger at the duplexer. cheers, s.
