Home |
Search |
Today's Posts |
#14
|
|||
|
|||
In article . net, Len Over 21
writes: In article . net, robert casey writes: Without a single poll to back me up, the following could be said to be accurate for 1911: Any Frequency: CW: 100% [on-off keying] Someone inserted a carbon telephone microphone in the feedline between the transmitter and antenna, and produced a crude form of AM. Couldn't have been much power else the mic would have burnt up. These mics vary in resistance along with the sound they hear. Yes, yes, yes, good old Reggie Fessenden did it. At least once with an audience on Christmas Eve, 1906. NOBODY followed that example. :-) One correspondent, an obvious fan of Reggie, thinks that "lots of folks" were doing AM with a special carbon microphone in series with the antenna lead. The "lots of folks" were restricted to Fessenden's work group at one station, perhaps four in all. [see Thomas H. White's early radio history in the USA papers, a fascinating look at that] There's nothing in Aitkin's histories (such as "From Syntony to Spark" to the tome I mentioned earlier) to indicate that anyone was bothering to emulate Fessenden's method. Lee de Forest wrote that he was able to do some AM low-power with his "audions" which surprised some USN radiomen in the NYC area at the time. AM was first done on a large scale in WIRED telephony, specifically for the "carrier" form of multiple circuit transmission (frequency multiplexing) on a single pair of long-distance wires. The telephone people were responsible for the upsurge of interest in "wave filters" and the formulation of the first passive L-C filter theory. John E. Carson (not the "Tonight" show host) came up with the first complete mathematical description of AM and FM. Reggie Fessenden IS responsible for the predecessor to the "BFO" when he was able to increase the intelligibility of his detectors by using a very small spark generator loosely coupled to that detector. Fessenden called it a "heterodyne detector." When Ed Armstrong invented the modern "superhet" in 1918 he was mindful of Fessenden's method, so Ed called his system a super-heterodyne. That's how we got that name as well as the familiar short term of "superhet." No, *all* activity on radio was legal. Anything not specifically outlawed is legal. Yes and no. The LAW defines what is legal and what is illegal. Without the LAW specifically covering it, it is neither legal nor illegal. That's a philosophical viewpoint on "legality." :-) English Law recognizes that people do a LOT of things and most of those are NOT concerned with any law covering it. Attornies can make very "learned" distinctions on it, but, in the basic terms of "legal" and "illegal," something not covered by any law simply IS and is neither legal nor illegal. 1961 was 43 years ago. Times change. Technology changes. The original posting of the first message in this thread appears to be nothing more than a refined Troll. :-) Technology of ALL radio, indeed most of electronics in general has changed dramatically with the introduction of the Solid State Era. So has the operating practices over those intervening 43 years. Radio amateurs have been lagging the practices of the rest of the radio world since that time despite the protests of the most die-hard "amateurs are in the cutting edge of technology" advocates. Those of us who were IN the electronics industry at that time (and before) were all able to see that. Amateurs who had no news of the rest of the radio world's advances (except long after the fact) will protest out of some ignorant pride in their amateurism, but that is necessarily true. Evidence can be found in the early 1960s ARRL "Handbooks" compared to the industry publications of that same time. I have nothing against any hobbyist defending their "turf" in scope of hobby activities. I DO have much against those hobbyists either stating that amateur radio hobbyists are "advancing the state of the art" just by existing or that all regulations should continue to reflect the PAST in all things regarding amateur radio practices. Those who wish to constantly re-create or re-enact the past by becoming the very best morsemen (according to older, outdated standards) can do whatever they like as far as I'm concerned. The problem occurs when morsemen get too full of themselves and try to "run the show" by demanding that all newcomers to amateur radio MUST pass a telegraphy test in order to obtain an amateur radio license. These morsemen don't run any show, they are but participants in the older arts of amateur radio. They aren't role models of what is good despite their claims of "superiority" in radio. |