The basic issue is that the sidetone is, indeed, a square wave, followed by a filter to reduce the harmonic content.
Like most Hams who've been around a number of years, I've listened to every sort of "sidetone" from a sawtooth wave to the squawks and bleats produced by keying a rig with the receiver still energized, so the K2's sidetone sounds just fine to me! As you reduce the frequency of the sidetone in the K2 the original filter values are less effective and you start hearing more of the harmonic content. The mods you mentioned were worked out by some builders to make the filter more effective at lower sidetone frequencies. You might want to try it. Whether it's enough to make the sidetone sound pleasant depends upon the individual. I don't think Elecraft ever modified the sidetone circuit because most owners seemed to prefer 600 Hz, where the "stock" filter is most effective at producing a reasonably clean, low-harmonic content sidetone. Ron AC7AC -----Original Message----- I have a K2, serial #2289, that has a second harmonic in the sidetone. The sidetone is set for 400 Hz because I do much better with lower pitches. The sidetone at 400 Hz has a definite square wave sound to it. The problem certainly is not present at 600 Hz, and I don't even want to try 500 Hz. I'd go lower than 400 Hz if the K2 allowed it. I talked to Don Wilhelm about this and he seemed puzzled. There is a post off of the Elecraft web site about this at http://www.qsl.net/ve3mcf/elecraft_reflect/K2_Sinewave_Sidetone.txt. But that thread is dated Winter 2000. I would think the K2 has gone through enough evolutions to correct this. Perhaps not? Has anyone had this problem and corrected it? The sidetone is useable but annoying. It also makes zero beating a signal a lot harder. 73, Steve N6VL _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
