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"Steve Nosko" wrote in message
... Steve's imbedded comments: "Avery Fineman" wrote in message ... In article , "Steve Nosko" writes: What's the essence of an AM sync detector? Extract the carrier (filter/clip/amplify the bajeebers out of it) then product detect the sidebands ? Steve N, K,9;d, c. i My email has no u's. ...locking a local mixing oscillator to the carrier frequency and mixing that with the whole thing. Ah yes! need a reliable LO. Absolutely not. In a homodyne receiver, it's only necessary to recover the carrier by way of a limiting amplifier. ... A carrier in-phase lock allows separate detection of the sidebands...which could be used to advantage such as having binaural audio modulation with AM. Ah yes... Back to the old three methods of generating / detecting sideband signals. What's being suggested here is a synchrodyne receiver, where an oscillator is locked to the carrier of the incoming signal. This requires a Costas loop and is not at all necessary for simple AM detection. A homodyne is sufficient. Chris ,----------------------. High Performance Mixers and / What's all this \ Amplifiers for RF Communications / extinct stuff, anyhow? / \ _______,--------------' Chris Trask / N7ZWY _ |/ Principal Engineer oo\ Sonoran Radio Research (__)\ _ P.O. Box 25240 \ \ .' `. Tempe, Arizona 85285-5240 \ \ / \ \ '" \ IEEE Member #40274515 . ( ) \ '-| )__| :. \ Email: | | | | \ '. http://www.home.earthlink.net/~christrask c__; c__; '-..'.__ Graphics by Loek Frederiks |
#22
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"Steve Nosko" wrote in message
... Steve's imbedded comments: "Avery Fineman" wrote in message ... In article , "Steve Nosko" writes: What's the essence of an AM sync detector? Extract the carrier (filter/clip/amplify the bajeebers out of it) then product detect the sidebands ? Steve N, K,9;d, c. i My email has no u's. ...locking a local mixing oscillator to the carrier frequency and mixing that with the whole thing. Ah yes! need a reliable LO. Absolutely not. In a homodyne receiver, it's only necessary to recover the carrier by way of a limiting amplifier. ... A carrier in-phase lock allows separate detection of the sidebands...which could be used to advantage such as having binaural audio modulation with AM. Ah yes... Back to the old three methods of generating / detecting sideband signals. What's being suggested here is a synchrodyne receiver, where an oscillator is locked to the carrier of the incoming signal. This requires a Costas loop and is not at all necessary for simple AM detection. A homodyne is sufficient. Chris ,----------------------. High Performance Mixers and / What's all this \ Amplifiers for RF Communications / extinct stuff, anyhow? / \ _______,--------------' Chris Trask / N7ZWY _ |/ Principal Engineer oo\ Sonoran Radio Research (__)\ _ P.O. Box 25240 \ \ .' `. Tempe, Arizona 85285-5240 \ \ / \ \ '" \ IEEE Member #40274515 . ( ) \ '-| )__| :. \ Email: | | | | \ '. http://www.home.earthlink.net/~christrask c__; c__; '-..'.__ Graphics by Loek Frederiks |
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