Search for a 600kHz switch mode power supply opperating in the vicinity of your repeater. These are usually found in boats as battery chargers. They are also starting to appear in wall warts on stuff like answering machines and routers.
I had on which would mix with the TX and desence on both offsets. You will probably be able to hear a fair amount of noise with a handheld tuned to the opposite offset, if so you can use a beam and a switch attenuator to fox hunt the source. Or use a portable AM radio to track it down. Also try running the repeater on a car battery and kill the breakers until the desense stops. Also a RC-850 controller with bad caps creates a fair amount of noise on 2m if the antenna is too close to the repeater. On 5/8/08, blisswheeler <[EMAIL PROTECTED]> wrote: > I've run into a problem that baffles me. > > I have two sets of WACOM WP-641 4 can Duplexers. They have been tuned > to TX on 146.96 mHz and RX on 146.36. One set was tuned in a > Professional Lab, the other I tuned myself. They tune very well with > excellent rejection ~90db. When I duplex into a dummy load running > 100W, I can inject a signal with an iso-tee and there is vertually > zero desense to the receiver. When I hook it to an antenna it > instantly experiences 30db of receiver desense. I can lower the power > to 3 watts or less and still have 20db desense. I have a GE Mastr II > repeater, but I've used a separate Transmitter and receiver and > experience the same results. > > I'm using double shielded RG214 for testing. I've also used 1/2" > heliax for testing from the duplexer to the antenna. I've used 3 > different antennas. 2 different colinear and a j-pole. The antennas > all have less than a watt reflected out of 65W forward. I've used > separate antennas on the TX and RX Cans with the same results. When I > terminate either TX or RX into the dummy load the desense disappears. > It appears that when the reactive component is introduced everything > goes to pot. > > It doesn't make any sense to me. Any Ideas? I'm stumpted.. :-( > > Thanks, > Bliss > > > ------------------------------------ > > > > Yahoo! Groups Links > > > >
