Bob, Not to worry about the logical function, different minds think of it in different ways. My thinking is that an active low on either the dot OR dash contacts makes the output low. That goes back to my old TTL thinking of wire ORs to extend the OR function. But if you use an OR function "upside down", it becomes an AND function. Strictly semantics and mindsets within the logic world.
You will be able to parallel you straight key and external keyer and computer keying connections together without isolating diodes as long as one of the external devices does not interfere with another one - the K3 will not care as long as it sees a low level on the key input. With the K3 and the paddle input, it is different than the K2. If you intend to use your paddles with the internal K3 keyer, you will have to plug the paddles into the PADDLE jack on the back of the K3. That is the only difference. 73, Don W3FPR Bob wrote: > Hi Don, > > OK, I was not sure about the K3 but threw it out there as > food for though. Maybe my choice of terminology was wrong but I'm > pulling both the Dash "and" Dot lines low through the diodes with the > straight key contact and do the same with the K1EL. The K2 does the > auto-detect. It is active low with the key so maybe NAND ? Or, and > I'm not trying to be facetious, did you mean that the different devices > are logical OR'ed . I actually have 4 devices that can key the K2 in > parallel. I didn't see any need to diode isolate them, only to combine > the separate dot & dash lines for single line keying. > > Works fine, but explanation may be lacking. > > 73, > Bob > K2TK > > Don Wilhelm wrote: > >> Bob, >> >> You will not be able to use the 2 diodes (BTW, that is a logical OR >> function - it is 'active low') with the K3. >> The K3 has a KEY input in addition to the PADDLES input. You can >> connect the paddles to the paddle input, but you will have to add a >> cable to the straight key to run to the KEY jack. Yes, you should be >> able to connect the straight key and the computer keying line in >> parallel. >> >> 73, >> Don W3FPR >> >> Bob wrote: >> >>> I'm going a little out on a limb here as I don't know if the K3 has >>> the same feature as the K2 does. >>> >>> The K2 acts as it is in a straight key mode if both Paddle lines are >>> pulled down at the same time. >>> I use a old Brown Brothers that has a straight key and paddle on it. >>> The straight key has two diodes >>> to "and" the lines so it can be used or the K2 internal keyer. Also >>> using a Radio Shack Y connector and >>> diodes "And"'ing also lets the K1EL USB keyer key the K2. In >>> addition the K24U program >>> can trigger the K2 memories. The K1EL also has its own paddle. Any >>> can be used at any time. The only >>> exception to that is that only one program can use the serial port to >>> the K2. >>> >>> That has not been a problem for me but if it were possibly a work >>> around could be with one of the virtual >>> serial port emulators. So far I've been happy with this flexibility. >>> >>> 73, >>> Bob K2TK >>> >>> > ______________________________________________________________ > 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 > ------------------------------------------------------------------------ > > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 8.5.375 / Virus Database: 270.13.19/2245 - Release Date: 07/18/09 > 05:57:00 > > ______________________________________________________________ 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
