CW keying interfaces

[ct-user@sttng.mlo.dec.com]

Pete,

At hi pwr levels any xsistor-based switching system has failed here from time
to time. The optoisolator trick is indeed the way to go. Keeping the RF out
of the computer is  a matter of keeping RF off the keying line. That is a
tall order in my station - miles of cabling for computer, coax, control and
rotator line, etc. Once, while remotely keying the rig from my 75M vertical
(250' away) I blew out the COM3/COM4 add-on board in the PC. I now disconnect
the keying line from the rig to the computer altogether. I suspect you are
getting RF into the LPT port, as I have experineced. During CQWW, if I set
power level >1000 W and/or turned beams at the shack (only 80' away) CT would
go into CW-lock mode, as you're experiencing with N6TR. Thanx for mentioning
the optoisolator trick, I have to do that here B4 the contest season begins.
..............................................................................
73 de Walt Kornienko  -  K2WK          Frankford Radio Club
Internet:  waltk@pica.arm.mil          Snail: RR1 Box 919, Lafayette, NJ 07848
DX PacketCluster: K2WK > W3MM          Packet: K2WK@NX2P.NJ.USA.NA
______________________________________________________________________________