Motorola Gm3688 Service Manual Direct

The Motorola GM3688 Go to product viewer dialog for this item.

Motorola GM3688

In the world of land mobile radio (LMR), few names command as much respect as Motorola. The is a testament to the company’s engineering prowess. As a rugged, high-power mobile transceiver (typically 25-40 watts in the VHF and UHF bands), the GM3688 has been the workhorse for public safety, construction, logistics, and farming for nearly two decades. Motorola Gm3688 Service Manual

  1. Receiver Circuit: The receiver circuit includes the front-end amplifier, mixer, IF amplifier, and discriminator.
  2. Transmitter Circuit: The transmitter circuit includes the power amplifier, modulator, and pre-emphasis circuit.
  3. Microcontroller Circuit: The microcontroller circuit manages the radio's functions, including the synthesizer, memory, and user interface.
  • Manual section: 5.5 (RSSI Calibration)
  • Cause: The Received Signal Strength Indicator voltage is out of spec.
  • Fix: Inject a -47 dBm signal at the antenna jack; measure test point TP6 (RSSI). Adjust squelch trimmer R123 until the radio unmutes cleanly.

Replacement Parts

: A list of official Motorola part numbers for mechanical and electrical components, such as the 16-pin connector or standard microphones. 2. Technical Specifications Overview The Motorola GM3688 Go to product viewer dialog

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