Back in the 50's and 60's there were many articles in the mags of hams mounting a headphone in one end of a tube. The length of the tube was cut to provide resonance at the desired audio frequency. Such filters actually provided pretty sharp responses for CW operation for Hams with slender wallets (like mine).
73, Ron AC7AC -----Original Message----- From: Elecraft [mailto:[email protected]] On Behalf Of lstavenhagen Sent: Wednesday, March 23, 2016 12:33 PM To: [email protected] Subject: Re: [Elecraft] Pileup Mush (was:audio board) Yes, my first RX when I was a child in the 70's was a Realistic from Radio Shack. I can't remember the model but it was as wide as the Red Sea, especially with the built-in speaker. At one point I got a set of comm headphones with a hefty peak in 400hz or so range and it really worked well as a "poor man's" audio filter. That was back in the days when novices could only use CW so it didn't have to sound good on AM sigs (and it didn't), just good on CW tones. It really helped a bunch - I wish I still had them! 73, LS W5QD -- View this message in context: http://elecraft.365791.n2.nabble.com/Re-Pileup-Mush-was-audio-board-tp761547 3p7615489.html Sent from the Elecraft mailing list archive at Nabble.com. ______________________________________________________________ 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]
