Brian, At the KEY input to the K3, it is the low level voltage that is important, not the high level. My guess is that your external keyer is not going to a low enough level to fully discharge the .001 capacitor that is on the key in line inside the K3. Do your keyers have a resistor between the keying output line and the K3? If so, that could cause slow keying. It would be best to evaluate the low level during a string of dots with a DC input on an oscilloscope to see if the low level shifts after a couple dots. If it does look for any cause of resistance (or added capacitance) between the keying driver and the K3 input.
73, Don W3FPR Brian Alsop wrote: > Hi Keith, > > Unfortunately no bug. > > Now that you mention it, it kind of sounds like a bug when one holds the > dit side down for a long time. After a number of dots, each gets to > sound longer and longer and more slurred. > > For what it is worth, the computer interface to KEY in uses an NPN > transistor. The keyer uses a 2n7000 FET. The FET on state has a really > low voltage drop. K3 Key terminals have an open circuit voltage of 4.7 > V (would have expected closer to 5). The K3 displays a power-in > voltage of 13.7V. Have removed all connections to the K3 but > earphones and KEY. Problem does not go away. > > Wierd. > > 73 de Brian/K3KO > > _______________________________________________ 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
