Sinclair recommends against tuning under power because it is possible the finger stock might arc inside the cavity. I suspect most folks (myself included) have turned the pass knob under power. You could use a signal generator and receiver with a very good S meter to set the Pass tuning, then after tuning pass, go the the reject frequency and tune for minimum signal. You may have trouble with leakage from the generator into the receiver and false peaks and dips. Certainly it can be done, without a sweeper and tracking generator, but proper equipment makes the job much easier. de nu5d
ipscone wrote: > How much trouble is there in tuning a duplexer? I'm not equipped, at > present, with a lot of test equipment. I suspect I could get one pre-tuned > to a test frequency pair but eventually it would be moved to a cordinated > pair and I'd be stuck with tuning it. :-) I'm sure I could get local > repeater owners to help but just curious how difficult it is to tuning. It > seems that it should be pretty straight forward but I was wondering if it's > possible to tune them by watching power meters and such. Or does it require > freq generators and spectrum analyzers. > > Also, are there any that have discrete tuning capability (i.e. marked for > various freqs. > > Finally, can someone recommend a good duplexer for the 70cm band. > > Thanks > > -- Belton Ham Expo - The Cheapest Hamfest around.
