[Elecraft] K2: sending PSK31

[Peter Wollan]

The documents on the Elecraft site suggest that sending PSK31 requires a
cable to the K2 mic plug, with a 10:1 voltage splitter to reduce speaker
voltage to mic levels, and a PTT switch which could be as simple as a
manual toggle.  Is the PTT switch needed?  Has anyone used vox on the K2
for this?

I'm using the excellent Cocoamodem program on a Macbook, so far only for
receive.  A simple stereo cable seems to work fine, and the program has
a spectrum display feature that works quite well for setting filters --
a substitute for Spectrogram.  Now I'd like to send, too.  It doesn't
look very hard, whether the PTT switch is needed or not, but it would be
nice to hear if someone else knows that vox either does or doesn't work.