At 9/6/2009 11:36, you wrote: >Hi, > >I have read the large majority of messages on here and the Repeater >builders site, and I am still lost. >This is the first time I have worked with a repeater in my 30 year ham >career and am learning something new everyday.. > >We installed a GE Mastr II running into pre-amp, a BandPass and then a 6 >can duplexer. The antenna is Hustler G7-144 and 1/2in hardline up 65 feet. > >The duplexer was set up with service monitor at the test site prior to >installing it here. > >When I go above 10 watts out all we hear from the users is a lot noise and >very little voice. As the power goes higher (when radio heats up) the >noise gets so bad that we can not make out a thing the people are saying. > >The SWR between the radio and the duplexer is 1.1 at 5 w and 1.15 at 7.5 >watts. Of course as we go up in power to 20 watts out we have 1.3 SWR. > >On the antenna side of the duplexer the SWR goes up to 1.4 at 20 watts and >1.2 at 7 watts and very little at 5watts (meter hardly moves).
What model of watt meter are you using? Typically the accuracy gets worse at the low end of a particular range, so unless you're switching ranges/replacing slugs to keep the forward indication at the top 50% of the meter's scale, the accuracy may degrade. Could also be a TX that's going dirty at the higher power level. If you aren't using an isolator between the TX & duplexer, I'd try that first. Sometimes the Mastr II RFPA doesn't "like" the pure reactance of the notch in the duplexer. Bob NO6B
