The input can accept the full RS232 range, +/- 25 V. But 0-5 V will also work. In fact 0-3 V will work.
Wayne N6KR On Sep 25, 2012, at 10:55 AM, Douglas Faunrt N6TQS +1-510-655-8604 wrote: > I assume that TTL-level means it works with a +5V/0V swing on input to > the radio? > > 73, doug > > > > On 25-Sep-12 14:33, Wayne Burdick wrote: >> Brian, >> >> The ACC1 port on the K3 is fully compatible with the RS232 standard, >> although it uses 0 V rather than a negative voltage when transmitting >> a low unit. This is the same TTL-level interface we use in several >> other products including the XG3, W1, W2, and K144XV. We offer both >> RS232 and USB cables that work with this port, and as far as I know >> these cables work with all laptop and desktop computers. >> >> You can certainly roll your own. I'll send you the schematic of that >> portion of the circuitry. >> >> 73, >> Wayne >> N6KR >> >> >> On Sep 25, 2012, at 7:09 AM, Brian Lodahl OZ2BRN wrote: >> >>> 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 >> >> ______________________________________________________________ >> 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 ______________________________________________________________ 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
