Years ago the standard "headphone" was a magnetic transducer using a strong metal disk diaphragm. There was almost no way one was going to damage them by over-driving them.
Most professional radiomen (CW operators) wore the 'phones on their head in front of their ears, not over the ears themselves. That way the radioman could carry on a conversation while copying messages, either in their head or on a "mill" (typewriter) and his/her ears were never at risk. In a very marginal, weak-signal situation the radioman might move one headphone back onto his ear briefly. Also, all the concern over a 'sine wave' tone is a modern affectation that still gets a chuckle out of me and many other OTs. Professional CW operators and Hams alike seldom cared if the tone they heard was a sine wave, a square wave or even some odd-ball sawtooth or triangular waveform. For many, many years my personal favorite sidetone monitor was an RF-activated sawtooth wave generator. I operated some gear in professional/military installations which the "sidetone" heard while sending was no tone at all, just a confused bunch of bloops, squeals and blasts of hum from a monitor receiver. No one thought anything of it. The bottom line is expectations change. Back then we thought nothing of taking five or ten minutes to tune up on a different band. Many Hams built their stations to operate on only one band. And some of us are still out there, Hi! Ron AC7AC ______________________________________________________________ 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
