Anyone experiencing low audio levels on transmit when in packet mode and 
using the rear 5-pin DIN connector may find this mod useful. It worked for me.

C65 which connects the AFSK input from the TNC to the mic line has the
standard value, .01uf. In my case this caused severe attenuation of the AFSK
signal to the point where I was unable to connect to anything. Replacing C65
with a 0.1uf cap cured the problem.

73 - Ian, AA2ES@WA2AAR.NJ.USA.NA