If getting to exactly the sidetone frequency works, an instrument tuner box (or app) might do the job. I don’t know enough to recommend one, but I see some devices for $30 or less and some apps ranging from free to a few dollars.
wunder K6WRU Walter Underwood CM87wj http://observer.wunderwood.org/ (my blog) > On Jun 9, 2020, at 2:29 PM, Don Wilhelm <[email protected]> wrote: > > Tom Hammond N0SS's (SK) website is mostly intact thanks to the Mid Missouri > Amateur Radio Club. It is a valuable resource. > > You can find the files for the K1 and KX1 CW Tuning Indicator (SMD version) > at http://www.mmccs.com/mmarc/n0ss/index_k1.html. > > If you have capability to etch your own boards, Tom recorded full size > images. You might also try emailing Fred at FAR Circuits to see if he can > create the boards. I believe Tom may have used him as his board supplier. > > 73, > Don W3FPR > > On 6/8/2020 7:33 PM, Frederick Dwight wrote: >> If you do a google search on KX1 zero beat indicator or cw zero beat >> indicator you will see several circuits demonstrated. Some like the one >> which uses the LM567 (non SMT) part and had >> a white LED seemed to be good, much less than 100 Hz BW and had the >> schematic, but some others seemed to be much too broad, perhaps hundreds of >> Hz wide. My circuit >> needed quite a bit of audio drive, so rigged up a small 500-500 CT audio >> transformer and used the primary as a autotransformer to double the audio >> voltage >> to the circuit which did not change the earphone volume but enabled the >> detector to operate without opening up the audio gain too much on any of my >> rigs. >> Good Luck Rick KL7CW >> Sent from Mail for Windows 10 >> ______________________________________________________________ >> 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] > ______________________________________________________________ > 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] ______________________________________________________________ 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]
