Hi, I'm reposting this because I'm still struggling to get my customized CAT + CW interface for the Kx3 to work:
I attempted yesterday to wire up a TTL Serial cable from FTDI, containg both CAT as well CW keying (using #RTS), and I can easily get the CW to work (keying using #RTS through a 4N25 and two 1N5711 diodes for dit and dah), but it seems that the CAT does not work with this interface. My question again: -What is the "official" Elecraft electrical specifications for the ACC1 interface ??? What voltage levels for Rx and Tx, respectively, with respect to GND or Positive voltage ? -Does anyone have a schematic of the ACC1 interface for Kx3 that I can take a look at ? 73' Brian OZ2BRN Den 21-Sep-12 08:34, Brian Lodahl OZ2BRN skrev: > Hi Kx3 users, > > Other posts have previously dealt with the issue that the standard KXUSB > cable for Kx3 does not support CW keying from the computer to the Kx3 > radio, simply from the fact that as opposed to the ordinary serial > connection (old RS-232 standard), the RTS and CTS pins are not available > in the 3.5 mm, three-pin TRS jack connector for ACC1 in the Kx3. > > Pursuing this further, and not wanting to have more than one USB cable > to my PC from my Kx3 for all of my buisness on the PC side, I want now > to build a new interface cable using a custom cable assembly from FTDI: > > http://www.ftdichip.com/Products/Cables/USBTTLSerial.htm > > Then using either RTS or CTS flags in my PC's radio interface setup (log > program Win-Test) to pull the CW key connection in the Kx3, possibly via > a FET or Opto Coupler. > > - I have a 4N25 in mind for this ... with parallel coupling of two > 1N5711 to the paddle dit's and dah's. > I did the very same thing on my K2, and it worked like a charm. > > Checking the signal levels on my oscilloscope today on the ACC1 data > connection, I find: > > Tip connection = Rx data from the computer to the Kx3 = 5,0 - 5,2 volts > level (generated by the FTDI line driver) > Ring connection = Tx data to the computer from the Kx3 = 7,0-7,5 volts > level (generated by the Kx3 line driver) > both with respect to GND being the sleeve pin of the ACC1 jack plug, and > looking pretty, noise-free and free of any transients. Good, nice square > signals with good integrity. > > Baud rate of the data here is obviously configurable, and with your PC's > logging program so is the polling rate of how often the PC requests data > from the Kx3. > > My question :What is the "official" Elecraft electrical specifications > for the ACC1 interface ??? > What voltage levels for Rx and Tx, respectively, and what impedance to I > terminate with when I interface with e.g. opto coupler for my project ? > > Would I be OK assuming I just use a 5-volt TTL-level cable version here, > both ways Rx+Tx OK ? > > TTL-232R-5V: > http://www.ftdichip.com/Support/Documents/DataSheets/Cables/DS_TTL-232R_CABLES.pdf > > > 73' > Brian OZ2BRN > Kx3 # 1118, K2 # 6936 (to which I did the same mod) > ______________________________________________________________ > 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 > ______________________________________________________________ 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
