Motorola Gm3688 Service Manual |link| -

Detailed circuit descriptions of the transmitter and receiver paths.

Requires a high level of technical literacy to utilize fully. Motorola Gm3688 Service Manual

If you don't have a decent oscilloscope or a service monitor (like an HP 8920 or a Freedom R8000), do not touch the coils labeled "L" in the RF section. You will detune the receiver and likely make the radio deaf. Motorola Gm3688 Service Manual

Performance tests and acceptance criteria Motorola Gm3688 Service Manual