Not really, it's just the way we do it. Years ago, matching frequencies meant literally listening for the zero-frequency beat. It was always difficult, because the audio response of any receiver, as well as that of the human ear, drops off at low frequencies. Now you can achieve the same thing by matching the audio frequencies of the spot tone and the received signal, both of which are within the audio response range of both the receiver and our hearing. One can easily match frequencies within fraction of a Hz with this method. This only works, however, because receivers now have tracking sidetones, generated by exactly the same frequencies which produce the received signal beat note.
73, Scott K9MA On Feb 1, 2011, at 1:03 PM, Ralph Parker wrote: > Funny how 'zero beat' means something different today compared to years ago. Scott Ellington Madison, Wisconsin USA ______________________________________________________________ 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
