Hi all, a quick test on the PS-12 shows that it can be keyed with a keying
line connected between pin 1 and pin 3 on the 5-pin 270 DIN socket, on
extreme right hand bottom corner of the back panel ( This is slated for
connection to the WZ-6 and is used to blank the source on the retrace when
sweeping). Pin 1 is earthy.

As I suspected, the keying is upside down that is "make" generates a space
and "break" generates a mark. Using a simple Basic program in an old NEC
PC8201 (2MHz 80C85 ) the keying sounds OK at 15wpm.....about the maximum
this little old thing (the computer not 'NYK ......though there isnt that
much difference) will  run at. It sounds quite crisp coupled into the
receiver, with no signs of slurring. The internal soft keying seems to do
all that one might do with a key click filter. Spectran suggests that the
bandwidth keyed at this speed is about the same as I would expect from any
strong morse signal on the band.

Cheers de Alan G3NYK
[email protected]

....The program in the NEC 8201 uses the cassette-port motor-relay, which is
floating,  as a keying relay.

Cheers de Alan G3NYK
[email protected]