SUPERSTAR 3900 CHANNEL CONVERSION
1. The above modification will allow you to cover the frequency range of 28.300 to 28.500 with the Superstar 3900. This modification can be performed from the component side if special care is used when soldering the switch wires to Pin 12 and 13 of IC7 (Adder Chip). Or you may also locate these two pins on the bottom side of the circuit board, and solder them there.
2. Mount a SPST switch in a convenient location. Solder two wires from this switch to Pin 12 and pin 13 of IC7 (MC14008BCP). Be very that the wires do_ not touch any other pins once they soldered to IC7.
3. Once you have made sure that all connections are okay, apply power to the radio. Place the band switch to Band "D" for your new channels.