RACORDER - The Marine Black Box

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This audio output module combines the transmit and receive audio and adjusts the audio signal to a level suitable for connecting to Racorder.

It consists of an audio mixer and a low pass filter to reduce the possibility of RF getting into or out of the radio via the audio line.

The receive reisitor is 100K ohms, 1/4 watt. The transmit resistor is 1M ohms, 1/4 watt.

The module has two leads which connect to the receive audio at the top of the volume control and the transmit audio at the deviation control.

The module is mounted on a plate which mounts to the rear of the radio.

Remove the existing plate and mount the modified plate in its place.

If necessary trim the gasket so that it has a center hole capable of passing the circuit board of the module, leaving the perimeter of the gasket intact so that it can make a proper seal.

Connect the blue wire from the mod kit to pin 6 of J5. Pin 6 has a black wire connected to it.

An easy way to make the connection is to unplug the connector from J5, insert the lead into pin 6 of the connector and reinsert the connector into J5 making sure the lead stays in the pin 6 hole and does not short to any of the adjacent pins.

Locate R27, a vertically mounted resistor next to the deviation control.

Scrape some of the insulation coating from the upper lead in the bend and solder the white lead from the mod kit.

The completed installation

Updated June 21, 2004