GTX dropping off

[RidgeRunner]

A friend and I are using some GTX's currently on 927 TAR and they sound fine about 15 watts out and good sensitivity. Problem is we want to set them up for a repeater use and the TX drops to about 6 watts are 902 and the sensitivity just goes all to hell. The other thing is on 927 we had the audio all tuned and sounding good dropped down to 902 we had about 8 kc of audio. I see on the GTX 902 amateur conversion that whoever did it had good sensitivity and RF out on 902 as well. I would also like to know why my audio is behaving like that as well. The last thing is anyone have a service manual on .pdf they would let us have?