This document is the Garmin GMA 340 Audio Panel Installation Manual, which introduces the installation methods and precautions of this product.
This manual covers the installation of the Garmin GMA 340 audio panel family, describing hardware layout, connector locations, and required aircraft accessories. It includes detailed wiring diagrams, mounting instructions, and post‑installation checkout procedures for the standard, helicopter (GMA 340H), and dual‑ADF versions.
The document also lists technical specifications such as TSO compliance, temperature range, weight, dimensions, power requirements, and audio input capabilities, as well as a hardware modification level history for service updates.
| TSO Compliance | TSO‑C50c, C35d, JTSO‑C50c, JTSO‑2C35d |
|---|---|
| Temperature Range | -20 °C to +55 °C |
| Weight (unit only) | 1.2 lb (0.6 kg) |
| Bezel Height | 1.30 in (33 mm) |
| Supply Voltage | 11.0 V to 33.0 VDC |
| Operating Current | 2.2 A (normal operation, 13.8 V, speaker on) |
| Altitude Capability | 50,000 ft |
| Transceiver Inputs | 3 |
| Receiver Inputs | 5 (6 in Dual ADF version) |
| Input Impedance | 500 Ω (800 Ω DME input in Dual ADF) |
| Input Isolation | ≥ 60 dB |
The GMA 340 operates from 11.0 V to 33.0 VDC.
The panel has three transceiver inputs.
It can operate from –20 °C up to +55 °C.
The unit only weighs 1.2 lb (0.6 kg).