Bob, Yes, the 8T line is ALMOST opposite 8R - but not quite. 8R goes low prior to 8T being asserted and 8R can be held low after RF disappears for a period of time determined by the 8R HOLD menu parameter.
The 8R line is usually the one used for external keying. There is an External Amp Keying Circuit schematic (and a partial kit) on the Elecraft website. Tom Hammond has an updated version of the circuit that you can find at www.n0ss.net - this is similar to the amp keying circuit found in the KPA100. There is no 8T hold menu parameter - the 8R signal goes low 15 to 20 ms prior to the onset of RF. 73, Don W3FPR > -----Original Message----- > > I'm pretty sure I now understand the operation of 8R and 8R HOLD. > > Is 8T the inverse of 8R (ie goes high during transmit)? > > Is there a 8T HOLD option anywhere? > > At the moment I run 100% digital modes and I switch my linear via > the RTS line on COM1 (which goes high on TX) and an > opto-isolator. I would like to use the opto-isolator circuit for > SSB and it looks as though the 8T line might do the trick. > > _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
