Yes, floating. Indeterminate if feature enabled & line not set externally.
(Guess how I know..? hi) 73 Josh W6XU Sent from my mobile device > On Oct 19, 2018, at 9:47 AM, Brian Moran via Elecraft > <elecraft@mailman.qth.net> wrote: > > With my early K3, I'm attempting to control the TX_INH line on the ACC > Connector, and am finding this odd (to me) behavior. > Starting with the radio off, I'm driving the pin with either 0 or 5v through > a 6.6K resistor per the Elecraft manual. I set the TX_INH mode to HI in the > config screen, and even with the line NOT driven, TX_INH is indicated by the > flashing TX in the display. > If I get out my Fluke VOM, I see that there's around 0.2v measured at pin > 7... BUT THEN THE TX INHIBIT goes off (that is, it starts working as > described in the manual)? Is the TX_INH line floated in the radio? > Do I need to also "pull down" this line to ground through a suitable > high-value resistor? > > Adding a 470K ohm to ground seems to make everything happy. If this is > expected behavior (requiring pull down as well as pull up), perhaps this > could be mentioned in the manual in the future (maybe it only matters to my > era of K3 radio -- #512) > > What makes this a little more difficult to debug is that after the line has > been measured with the meter, causing it to work, TX_INH sometimes continues > to work (High=inhibit, LO=tx). Until I power cycle the radio. > Anyone who has done this before have any insight?thanks,-Brian N9ADG > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
