Click to enlarge 1. Disconnect the wire in the middle of the connector J408 on the principal plate (Mother board).
2. Take off (remove) the adjustable VR211 (TX-frequency adjust).
3. Connect the wire you took off (J408) and solder it at the place middle point of the adjustable VR211 (Diode side D215)
4. Cut the middle of the wire linking the modulation between MIC CONNECTION plate and MIC GAIN plate, position 2 on both connectors (near the orange wire).
5. For the part of the wire connected to the MIC CONNECTION plate; solder the other side onto J408 on the principal plate.
6. For the part of the wire connected to the MIC GAIN plate; solder the other part on VR211 strap side (The other part is on the ground)
7. Replace R408 1kohm by an 500 ohm adjustable potentiometer
8. Solder the two contacts of the potentiometer MIC GAIN. 9. Set MIC GAIN in middle, and adjust R408 500 ohm potentiometer to get 27.205 MHz. 10. You can now use MIC GAIN for adjusting the center frequency.