Ian, The 600 kHz split in the 2m band generally requires at least a four cavity duplexer and around 80 dB isolation with modest power and a good receiver with an integral front-end preselector. Solid-state PAs often are rather noisy to begin with, and driving them with a synthesized exciter adds even more noise.
A solid-state PA with 100 watts or more usually calls for isolation in the 90-95 dB range, and this is normally met only with a six cavity duplexer. The goal of designing a first-class repeater is to achieve no desense at all when the transmitter is active in full duplex. I do not think you will be able to achieve that goal with fewer than six cavities. Rather than trying to burn up power in an attenuator, just run the PA at a lower power level. But be careful- some PAs are unstable when run at reduced drive levels. Your mileage may vary... 73, Eric Lemmon WB6FLY > Ian Ashford wrote: > > At the moment I am testing a 2m 4 can duplexer with a 25 watt > transmitter and all is fine. > > I wish to remove one of the cans in the duplexer and use it for > another purpose (part of another duplexer actually) > > If I lose a can from the tx arm can I "clean up" the transmitter with > (say) a 120w solidstate amp followed by a high power 6dB pad? > > has anybody in the group tried this? > > Ian > G8PWE > > > > Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
