> The advantage is that I could possibly pull out the RTS line from my one > RS232 cable > to the computer, and simply add it to the amplifier PTT plug in ACC2. I > would not > have to build a transistor switch to directly trigger the PTT line, which > would have > to be broken out from the custom MIC plug.
Hi Lance, you should *NOT* apply RTS directly to the GPIO pin! RS-232 levels go up into the +/-20 volts region per specs and that would probably damage the microcontroller in the KX3 (at least this pin). Maybe Wayne can shine some light onto if GPIO is directly connected to the MC and thus can only accept 5 V or if there is something else in-between. Please don't be mistaken by that you can apply RTS directly at the K3 because that has a level converter built in active also for RTS/DTR pins while the KX3 probably won't (see above). So an "interface" is needed anyway (1-transistor-interface), that's why I originally asked what the advantage of using GPIO for PTT would be (besides maybe easier cabling). A better solution might be to simply use VOX on DATA A then also for WSJT (just for easier cabling, I would still prefer "real" PTT on the mic connector) and use GPIO's TX-INHIBIT functionality together with a smallish sequencer (could be built into the amp, too). Then you could be sure that the radio is not putting out any HF before all other equipment (PA, pre-amp, etc.) has switched and the TX-INH is unlocked. I am doing exactly that on my K3 ... and others, too. ;-)) Vy 73, Olli - DH8BQA http://www.dh8bqa.de ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
