Mathew, Just as there are many different designs of duplexers, so there are different methods of tuning them. The best source for tuning a particular duplexer is the manufacturer of that unit.
I am not familiar with the Cushman CE-6030 service monitor, so I don't know how suitable it is for tuning duplexers. As a minimum, the service monitor or spectrum analyzer should be very accurate and it must have a tracking generator. Many spectrum analyzers are of only modest accuracy; it is difficult to tune a 2m duplexer to a 600 kHz split, when the analyzer's frequency setting cannot be known any better than 100 kHz. Most service monitors are much more accurate than a spectrum analyzer. A return-loss bridge is a valuable accessory for tuning the bandpass of a cavity, and for balancing the input and output loops. An RLB is an inherent feature of a network analyzer, and that is why most duplexer manufacturers use them on the production line and recommend their use for field retuning. While it is true that almost any duplexer can be roughly tuned to perhaps 95% of its optimum tuning with very crude instruments- a handheld radio and an RSSI meter, for example- that last 5% is usually attainable only with a network analyzer. Some repeater owners feel that extra 5% is important, and some don't. EMR Corporation has a very informative Application Note on duplexer tuning here: <http://www.emrcorp.com/images/tech_papers/tech_cover/antenna_duplexors(15-26).pdf> 73, Eric Lemmon WB6FLY w9mwq wrote: > > Anyone know any good books that will teach me how to go about tuning > duplexers. I've downloaded several articles, but need something > that goes in depth. Or if anyone is willing to work with me, it > would be appreciated. I have a Cushman CE-6030 SM to work with > here. Thanks! > > Mathew > > > Yahoo! Groups Links > > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
