But “audio” could be shorthand for “audio frequencies” instead of “radio frequencies”. 10 kHz is a reasonable frequency for AF. I’m quite sure that my audio amplifiers do not amplify with compression waves.
wunder K6WRU Walter Underwood CM87wj http://observer.wunderwood.org/ (my blog) > On Mar 23, 2017, at 3:56 PM, Jim Brown <j...@audiosystemsgroup.com> wrote: > > Right. What is being transmitted is an electromagnetic field, NOT a sound > field. Sound is AIR (or water) vibrating. Sound waves travel a bit faster > than a foot per msec. Sonar uses sound. The system Mike is talking about is > radio. > > Radio is an electromagnetic field, which the simultaneous existence of an > electric field and a magnetic field at right angles to each other, and they > move through space at the speed of light. We can't hear radio waves, but we > could hear high frequency sound waves if the radio waves were somehow > detected (the trusty non-linear junction) and caused something to vibrate (or > even to arc). > > 73, Jim K9YC > > On Thu,3/23/2017 3:03 PM, Mike Morrow wrote: >> I didn't understand the reference to audio either. >> >> When I on the crew of a US ballistic missile submarine more than 40 years >> ago, our main communications receivers were AN/BRR-3 units whose full >> frequency range was only 14 to 30 kHz. These received signals from coastal >> stations operating at megawatt output levels, but there was no one near such >> a station with his ear drums damaged by or even sensitive to the station's >> continuous output.:-) >> >> Anyone can listen to such signals as they exist today. > > > ______________________________________________________________ > 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 > Message delivered to wun...@wunderwood.org ______________________________________________________________ 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 Message delivered to arch...@mail-archive.com
