[Yaesu] keying voltage question

[Danny Pease]

I have a question about keying the FT-950 through the RTTY/packet jack. I
built a W9XT sound card interface and it does not key the radio through the
RTTY/packet connector. I can measure the key out pin of the interface and it
goes to .7 VDC when the keyline from the com port goes high. The interface
uses a standard opto-isolator, a 4n32 I think. The radio does key if I
ground the wire connected to the digital key pin of the RTTY/Packet jack. We
have tried the radio in SSB, RTTY and packet modes with no change. Does the
FT-950 need to be pulled lower than .7 volts to key?

NG9R