4
A VOR test button (VT) is provided for testing navigational systems; depressing the
button provides a ground on the appropriate rear panel contact.
The adjustment hole (D) by the MHz switch permits operator adjustment of the display
dimmer range for optimum nighttime viewing. The adjustment hole (S) by the KHz
switch permits operator adjustment of the squelch threshold.
The MX385 is comprised of eight replaceable subassemblies; five of the subassemblies
are contained in shielded modules to reduce radio frequency interference. The five
modules are the NAV receiver, the NAV synthesizer, the COMM receiver, the COMM
synthesizer, and the Transmitter.
The remaining three subassemblies are the Rear Panel Assembly, the Front Panel
Assembly and the Computer Board. The Rear Panel Assembly contains the Audio
Amplifier, the power converter, the Power Line Filter, and the T/R switching. The Front
Panel Assembly contains the digital displays and associated driver circuits, the functional
select switches and the volume controls. The Computer Board contains the
microprocessor, the memory, the Program storage, and the Channeling circuitry.
Also contained on the computer board are the audio processing circuits.
The subassemblies are interconnected with plugs to facilitate module replacement. For
equipment repair it is recommended that complete subassemblies be replaced.
As an aid to locating the defective subassembly a set of analog test points are provided.
The analog test points include the receiver tuning voltages, the synthesizer control
voltages and the AGC lines.
To Next Page
Loading...
