Thanks Don, that's good news. I'm not expecting perfection - just getting close will do for now.
73, Jim KO5V -----Original Message----- >From: Don Wilhelm <[email protected]> >Sent: Oct 29, 2018 2:53 PM >To: Jim KO5V <[email protected]>, Elecraft List <[email protected]> >Subject: Re: [Elecraft] K2 frequency counter question > >Jim, > >Of course that can be done. You would need to construct a coaxial >counter probe similar to the internal probe (with a 10pF capacitor in >series with the tip), but unlike the internal probe, you would have to >provide a ground lead to the shield near the tip end. (the internal >probe depends on the K2 PC board ground for the return path - that does >not exist with an external device). > >The length of your "probe" coax may reduce the maximum frequency that >can be used. With a short probe, the counter is good to 40 MHz. > >The K2 display is limited to 10 Hz resolution, and its accuracy is >dependent on properly setting the 4 MHz reference oscillator. You can >check that by tuning to WWV in SSB mode and using the N6KR method to >determine the correct setting. >The details of how to do that are on my website www.w3fpr.com K2 Dial >Calibration article. The use of Spectrogram to determine that the >transmitted audio tones are received at the correct frequency. If you >need Spectrogram, you can download it from my website opening page - >look near the bottom for the links. I have versions 5.17 and version 16 >there. > >73, >Don W3FPR > >On 10/29/2018 2:53 PM, Jim KO5V wrote: >> I have what may be a stupid or naive question: has anyone used the built-in >> frequency counter in a K2 to measure the frequency of a circuit external to >> the radio? >> >> I found what may be a reference to this, done by a French ham, but his link >> no longer works. If this is possible, any info (especially potential >> gotchas) would be greatly appreciated. I have built a couple of nixie-tube >> clocks as Christmas gifts, and I need to adjust their internal frequency >> references. The output is a 400khz, TTL level square wave. I know I probably >> need more precision that the K2's counter may have, but right now, I just >> want to get as close as possible. >> ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
