Steve, I have not yet seen an answer on the reflector, so I will offer some comments. First, I do not think your pulser will hurt the K2 in any way. Secondly, I am at a loss to know why you do not see as many bars in the K2 LED display as you do in TUNE. The bargraph is relatively fast responding and should indicate the power level being transmitted. It may be that your pulser ON duration is too short and it causes a 'flicker' in the display that is not seen by the eye. It would be interesting to see what an oscilloscope connected across the K2 output would reveal (the oscilloscope display would react in even less time than the bargraph).
So, bottom line, you may be seeing a natural result of the pulser ON time rather than an actual fault of the K2. Is there an easy way to double the ON time for your pulser? I find it hard to believe that 24 ms of ON time would cause any problems for your amplifier - it certainly would not pose any problems for the K2. 73, Don W3FPR Stephen W. Kercel wrote: > Elecrafters: > > I built a tuning pulser to use with my K2/100 to tune an external linear > amplifier. The pulser is the AG6K design. The pulse is 12 ms on and 24 > ms off, and repeats about 28 times per second. This is (by design) much > faster than the normal 25 wpm or so keying out of the keyer. > > The interface between the pulser and the K2 is a 2N2222 NPN transistor > used as a switch. The key line to the K2 is connected to the collector > of the transistor (nothing else is connected to the collector), the > switching data comes in through the base, and the emitter is grounded > both to the ground side of the pulser circuit and the ground side of the > keying line back to the K2. > > I notice what seems to me to be an odd phenomenon when I key the K2 with > the pulser. When I first switch on the pulser, the power level in the > little LED power meter on the K2 shows the same power level as I get in > normal keying. However, after the first instant, the power level > indication drops one bar lower (and then stays there as long as the > pulser is on) than the power level indication under normal keying. This > effect occurs independent of the power level that I set. It happens with > the K2's 100 Watt amplifier both in and out. > > Is this simply an artifact of the metering circuit caused by the > peculiar duty cycle of the pulser? > > Most critically, will it harm the K2? > > Should I do as one alternative keying scheme shows, and use the > transistor to key a reed relay and use the reed relay (which would > simply hard short the K2 keying line on key down) to key the K2? > > TNX & 73, > > Steve Kercel > AA4AK > > > ______________________________________________________________ > 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: 8.0.237 / Virus Database: 270.11.13/2001 - Release Date: 03/14/09 > 06:54:00 > > ______________________________________________________________ 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
