easy way to detect desense on an amateur radio repeater

[@johnbingel]

RX problems can be better understood and fixed if one forgets the word desense. Desnese implies the receiver has lost sensitivity when in fact receiver's sensitivity never varies. Desense is a term used to define a SYMPTOM that appears to be loss of receiver sensitivity. This video demonstrates sending a signal that exceeds the noise floor just enough to trip the repeater. When the repeater transmitter turns on, it's phase noise raises the noise floor above the signal, the receiver can no longer distinguish the signal from the noise and the repeater drops out. The receiver itself was no less sensitive in either case. The culprit here is the TX raising the noise floor. The TX side needs fixed not the RX side!

[@obeyconformtoday829]

Good way to burn out a HT. At least use a dummy load

[@TheDillio187]

a dummy load isn't a bad idea, but you're not going to hurt an HT like this using only 100mw for a minute (which the FT1DR does on L1)

[@randallgray5294]

Hello I see you're having the very same issue I am with a RX desense of a GMRS repeater. I am using two separate antennas one for RX and one for TX both spaced about 20 feet apart and a 6 cavity tight bandpass filter on the RX with nothing on the TX side.. It looks like I will need a ton of TX depth on a notch filter to remove it... Have you fixed yours yet?

[@TheDillio187]

I had the tuning loops repaired on my DB Products 4 cavity duplexer and it works great now. It has 2 cans on RX and 2 cans on TX. You need TX filtering!