Folks, Jack Brindle sent this privately, but I must say he is correct - a computer or external device that connects to pin 1 can create a ground loop. While that will not likely harm anything electrically, it may make functions 'work strangely'.
Jack and I both did a bit of web research of the real RS232 standard, and we discovered that the EIA standard specifies the DB25 conector, but nowhere could we find the DE9 connector in the standard unless it has been updated beyond the RS232-D level - so the use of that connector is not really a standard, but it certainly is commonplace. One should not assume that any particular connector implies any kind of standard. As an example, the 25 pin DB25 connector is used both for a real RS232 serial port and on most PCs as a printer port. 73, Don W3FPR > -----Original Message----- > From: Jack Brindle [mailto:[EMAIL PROTECTED] > Sent: Monday, October 24, 2005 11:00 AM > To: [EMAIL PROTECTED] > Subject: Re: [Elecraft] MicroHam microkeyer > > > Don; > > Might want to rethink just one pin of that. A connection from the > computer to pin 1 of the KIO2/KPA100's DE9 will probably create a > ground loop. Only connections to pins 2, 3 and 5 are needed. > > Pin 1 is the ground for the non-RS232 stuff (Auxbus, etc.). > > On Oct 24, 2005, at 4:38 AM, Don Wilhelm wrote: > > > If the Microkeyer has connections only to pins 1, 2, 3 and 5 of the > > 9 pin > > connector, one can safely plug it into the K2 directly. > > - Jack Brindle, W6FB > _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
