[Yaesu] FT-847 CW Keying

[Jim]

I've been using one of the standard homebuilt computer keying interfaces with my Kenwood TS-850 for several years.  It is one that plugs into the serial interface on the computer and uses a 4n33 opto-isolator on the output.  If I remember correctly, it was built from a schematic from the Writelog or TRlog manual.  When I plug this into the FT-847, it puts the transmitter in a key-down mode.  I've tried reversing the output polarity of the interface, but it does the same thing.  Any ideas why it may not be working and how it can be modified to work with the 847?

	Thanks, Jim