I’ve thought the problem through further and have decided to use a simple mosfet switch in the connector shell to invert the TXInh logic sense and configure the KX3 for -TXInh instead of +TXInh.
Hard switching the GPIO pin showed that to be a usable workaround. 73! Chris Cox, N0UK [email protected] or [email protected] > On Aug 31, 2020, at 12:51, Chris Cox, N0UK <[email protected]> wrote: > > I wish to interface my KX3 to my portable 10GHz transporter system. I have > the transporter’s PTT sequencer configured to output a +ve TX Inhibit signal > which I have been using to prevent my current I/F rig from transmitting until > all relays have changed over to transmit. The current rig is a Yaesu FT-817. > > I want to be able to simply switchover the PTT/TXInh cable between the two > rigs, so that I can continue using the ‘817 as a backup in the event of some > problem with the KX3, and so was intending to us the KX3’s ACC2 GPIO TX Inh > +ve input just as I do the 817. > > However, it seems that the KX3 actually has some bias applied that requires > to be pulled low to enable the transmitter, rather than looking for removal > of the +ve signal. This will mean that I need more than to simple switch > over the physical connectors on the umbilical cable. Although not > insurmountable, it’s not exactly ideal. > > Anyone else done this or similar and, if so, what was your solution? > > 73 Chris > > > Chris Cox, N0UK > [email protected] > ______________________________________________________________ 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 Message delivered to [email protected]
