Jim, While you may be correct about the noise pickup, there is also concern about timing issues - if only because the performance has not been tested at longer lengths by observing the bit timings on the AUUXBUS.
Some time back I had discussions with Jack Brindle about about extending the cable length to the KRC2. He did indicate that there could be timing issues on the AUXBUS. Being a single wire interface, when a command is sent, the sending device waits for the expected response, and if it is not received in time, an error condition will be declared. Those are the facts as I know them, and I recall that 6 feet was considered an OK length because it had been tested - longer lengths had not been tested. Of course, this applies to the K2. The K3 may or may not be different. 73, Don W3FPR On 3/23/2012 6:04 PM, Jim Brown wrote: > On 3/23/2012 12:21 PM, Don Wilhelm wrote: >> I don't think you will get any smoke, but if you get "strange >> happenings" - like the KPA100 is not recognized, or doesn't give a >> response back to the K2 in sufficient time (command flow over the >> AUXBUS) and things get "mixed up" or you get ERR 080, the cure will be >> to shorten the cable. > I would not expect timing problems, but parallel wire cables are recipe > for noise and RFI problems, and making them longer makes that worse. I > don't understand why, but Elecraft seems still not to have gotten the > message that TWISTING is FAR more important than shielding in providing > immunity from RFI and noise. > > There are simple instructions on my website for using CAT5 cable for > this sort of application. > http://audiosystemsgroup.com/HamInterfacing.pdf The specific wiring > instructions are given for RS232 connections, and your cable is NOT, but > if you will be in good shape if you follow the conceptual instructions > of using one twisted pair for each signal circuit with the "colored" > conductor used as the numbered pin and all four "white/color striped" > conductors twisted together and tied to the connector shell. If you > have shielded CAT5, tie those four striped whites to the designated > return pin and tie the shield to the connector shells. > > 73, Jim Brown K9YC > ______________________________________________________________ > 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
