If you have a hard time hearing your own downlink but have no trouble hearing other stations, you may be experiencing “desense.”
Desense is where your transmitter signal overloads your preamp (or receiver) causing it to become temporarily less sensitive.
This problem mainly occurs on Mode-J satellite operation with 2m-Uplink and 70cm-Downlink because of 3rd harmonics of your transmitted signal!
Example: 145.900 MHz (TX) x 3 = 437.700 MHz (RX)
Unfortunately our original AMSAT-DL Mode-J Filter Kit from DL1CF is no more available since many years.
But there is a simple work-around:
More in the article from Anthony Monteiro, AA2TX.
I have been just asked and thought other's might have similiar problems..