We have received several reports of minor distortion of the DRU-2 transmitted audio when used with the TS-950SDX. Recordings made from incoming received sources do not appear to be distorted.
Cause: This characteristic is caused by an impedance mismatch between the DRU-2 output and the input of the microphone amplifier circuit in the TS-950SDX. The following modification will correct/improve this characteristic.
On the Microphone Amplifier Unit (X59-3710-01), which is part of Switch Unit (A) (A41-3240-00) (H/10): (The Microphone Amplifier Unit is a small daughter board located on the switch assembly that has the Microphone Gain/Power Output Control and the Speech Processor IN/OUT controls).
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.
- Change chip resistor R257 from 4.7 Kohm to 8.2 Kohm (RK73FB2A822J)
- Change chip resistor R262 from 4.7 Kohm to 1.5 Kohm (RK73FB2A152J)
Time required for this modification is 30 minutes or less.