Voice keyer Interface by G3SEK

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AF to MIC input 1200 Ohm, <1Vpp
AF from SPKR output 75 Ohm, <1Vpp
FT1000MP connection DVS2 connector
PC connections Sound card and serial port

This voice-keyer-interface is designed by Ian G3SEK, based on the design by Mark G4AXX. It provides complete galvanic isolation of all lines between an FT1000MP and a computer.

The RS232 interface, CW and PTT lines are all opto-isolated, and audio transformers are used between the radio and the sound-card.

The DVS2 connector on the FT1000MP provides the audio in, audio out, PTT and 9V (4mA) for the radio side of the interface.

A battery (PP3) is used for the positive supply on the PC side of the interface. Current consumption is 10uA average (<<1uA quiescent).

The negative voltage rails on either side of the interface are derived from the RS232 lines, this requires the specified low-current opto-couplers to be used.

Click on a thumbnail below to see a larger picture.

General inside view

unique visits since Nov 2005