SB-880 TM-201/401 Increased TX Audio 10-25-83 Some users of the TM-201 or TM-401 have reported they would like a slight increase in the microphone gain. Since there is no internal microphone gain control on these radios, as simple mdification to the supplied MC-48 microphone will accomplish the same results. Proceed as follows: 1. Unplug the microphone from the radio. 2. Remove the 3 Phillips head screws securing the rear of the microphone. (A number 2 tip is recommended.) 3. Remove the push-to-talk (PTT) switch bar, paying particular attention to how it is installed. 4. Gently remove the small printed circuit board by lifting straight up, and swing the board over t allow access to the component side of the board. 5. Remove resistor R10, a 560 ohm 1/4 watt resistor. 6. Adjust VR1 Counterclockwise (CCW) 60 degrees. 7. Carefully reassemble the microphone, paying particular attention to the routing of the various wires, placement of the cirucit board, and the PTT bar. 8. Reconnect the microphone to the radio and verify correct operation. Modification is not complete. Time required for this modification is 1/2 hour or less. CLM (c) 121589TKC