Reports of low COMP meter sensitivity, or noise on the transmitted audio when using the speech processor is normally a result of misadjustment of the PROC IN control. This control is very sensitive and is difficult to adjust properly.
150 ohm chip resistor, (RK73FB2A151J)
Change the value of R258 in the SIG unit (X57-4130-00) from 68 ohm to 150 ohm. This will increase the available adjustment range of the PROC IN control. This will make it much easier to properly adjust the control and thus avoid overdriving the speech processor circuit.
Caution: This modification requires soldering equipment rated for CMOS type circuits. It also requires familiarity with surface mount soldering techniques. If you do not have the proper equipment or knowledge do not attempt this modification yourself. Seek qualified assistance.
Time required for this modification is 30 minutes or less.