Jay, If you need to extend the dropout time to keep the relays held in longer, a simple delay extender circuit can be added to the K2 amplifier keying line - a 2 2N2222 darlington coupled transistors with 2 or 3 resistors, a large capacitor and a diode will do the job nicely.
73, Don W3FPR "Life is what happens when you are making other plans" (John Lennon wrote it in a book, Mike Cross used it in a song - I don't know who was first) ----- Original Message ----- From: "Jerry Summerall" <[EMAIL PROTECTED]> To: "Don Wilhelm" <[EMAIL PROTECTED]>; "Jay Kesterson" <[EMAIL PROTECTED]>; <[email protected]> Sent: Sunday, June 06, 2004 9:31 AM Subject: Re: [Elecraft] K2 is break-in only on CW?? Part II > The 8R line delay is not long enough to hold the last one or two relays on > my DEMI sequencers especially when running 15-20 WPM CW. I don't believe it > is hurting anything but I hate to hear the relays clicking continuously > while operating. At the same time, after using QSK CW, going to semi break > in is sort of annoying. > ----- Original Message ----- > From: "Don Wilhelm" <[EMAIL PROTECTED]> > To: "Jay Kesterson" <[EMAIL PROTECTED]>; <[email protected]> > Sent: Saturday, June 05, 2004 4:25 PM > Subject: Re: [Elecraft] K2 is break-in only on CW?? Part II > > > > Jay and all, > > > > There certainly IS a line in the K2 that can be used for sequencing > > switching of transverters and other external devices. The 8R line becomes > > active about 20 ms before RF is presented at the antenna jack, and the > > drop-out time can be adjusted via the K2 menu - so to my way of thinking, > > the needed sequencer is already built into the K2. > > > > The KPA100 amplifier keying output follows the state of this 8R line, and > > the signal is used in the K2 to Elecraft transverter connection (KIO2) to > > switch the Elecraft transverters. For those who are driving non-Elecraft > > devices with the base K2 (QRP), I suggest you look carefully at the 'K2 > > External Power Amplifier Keying Circuit' shown on the Elecraft website - > > Builder Resources area, then select Application Notes, Eric originally > > designed it for use with an external amplifier, but can do the same job > with > > external transverter equipment. > > > > I believe that easy-to-build keying circuit will do the external switching > > job you need - OTOH, if your external devices need more than 15 to 20 ms > to > > become properly active, you may still be in trouble, but that IS a > > relatively long time period, even for relay operation and you may have to > do > > some work on the transverter end to make it switch faster. > > > > 73, > > Don W3FPR > > > > "Life is what happens when you are making other plans" > > (John Lennon wrote it in a book, Mike Cross used it in a song - I don't > know > > who was first) > > > > ----- Original Message ----- > > > > > Thanks for all for the replies to my question. My concern is using the > > > K2 with V/UHF transverters, amps and preamps (some mast mounted). These > > > are usually controlled with a sequencer that hard keys the radio last. > > > In certain setups accidentally bumping the paddle and having the rig > > > xmit could damage equipment down stream. I can use the PTT line from the > > > sequencer, that would normally be used for hard keying the rig, to key a > > > relay that doesn't allow CW to get to the K2 till all the up stream > > > equipment is ready. However I use a foot switch and headset, that gets > > > switched to three different rigs, on SSB. The footswitch is used to turn > > > on the sequencers during both SSB and CW operation.. On weak signal VHF > > > we often switch between SSB and CW. If I use PTT, from the sequencer, on > > > SSB I haven't figured out a way to easily (automatically) disable the > > > SSB PTT line on the K2 when I switch to CW. Any ideas, beside unplugging > > > the mic connector or otherwise manually disabling the mic PTT line?? Is > > > there some signal point inside the K2 that is active or grounded only > > > during CW that could be used to possible drive a relay to disconnect the > > > SSB PPT line while in CW?? Or better ideas?? > > > > > > > > > _______________________________________________ > > Elecraft mailing list > > Post to: [email protected] > > http://mailman.qth.net/mailman/listinfo/elecraft > > You must subscribe to post. > > Subscriber Info (Addr. Change, Unsub etc): > http://mailman.qth.net/subscribers.htm > > Elecraft page: http://www.elecraft.com > > > > > _______________________________________________ Elecraft mailing list Post to: [email protected] http://mailman.qth.net/mailman/listinfo/elecraft You must subscribe to post. Subscriber Info (Addr. Change, Unsub etc): http://mailman.qth.net/subscribers.htm Elecraft page: http://www.elecraft.com
