The talkback microphone amplifier is adjustable in level from a front panel control and can be routed to the same destinations as the oscillator in addition to the CLEARCOM interface. Incoming communication from the CLEARCOM interface can be routed to the monitor system by use of the COMMS ON key.
A SIDETONE trimmer allows the level of sidetone to be adjusted. This is the amount of your voice that you will then hear in the headphones when using the CLEARCOM system. IC6A is used to amplify incoming communications and to reject outgoing talkback which travels on the same wire as the incoming talkback. PR6 alters the rejection and hence the sidetone can be increased or decreased. When talkback is used a DIM command is sent to the main board. Talkback audio is also incoming from the headset and this is fed to the CLEARCOM interface together with any audio from the console talkback microphone.
The COMMS ON switch has several functions as follows:_
To allow incoming talkback onto the monitor system by operating an electronic switch and passing audio over to the main board.
Allowing either the talkback microphone or the output of the CLEARCOM system to go to talkback routing.
Routing the talkback microphone to the CLEARCOM system.
Putting a call out on the CLEARCOM system.
Also located on the COMMS board are the FLASH oscillator for flashing lamps and the MONO solo switch circuit.
Q2 OPERATIONAND MAINTENANCE MANUAL 9601 | 65 |