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#1
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Is CW just FM without an audio signal? So, If I have a FM receiver, can I
install a CW audio filter and pick up CW. Such as... an IC 207H or BC 780xlt and a Vectronics CW Audio Filter. Thanks Matthew KC2KEI Scars are the proof that man can survive his own stupidity. |
#2
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Matthew and Wendy Plante wrote:
Is CW just FM without an audio signal? So, If I have a FM receiver, can I install a CW audio filter and pick up CW. Such as... an IC 207H or BC 780xlt and a Vectronics CW Audio Filter. Thanks FM receivers are designed to not respond to amplitude variations. CW is about as pure an example of "information conveyed by variations in amplitude" as one is likely to find. To cut to the chase, what you propose won't work. That being said, one can send Morse in a format receivable on an FM receiver, but it'll be MCW rather than CW. Feeding a keyed audio oscillator into an FM transmitter will produce MCW. The caveat here is it is legal here in the states only from 50.1 to 54 MHz and above 144.1 MHz. HTH de kg7yy -- The appearance of my E-mail address in any venue does not in and of itself constitute a solicitation of bulk or commercial E-mail. I don't want unsolicited commercial E-mail. |
#3
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Matthew and Wendy Plante wrote:
Is CW just FM without an audio signal? So, If I have a FM receiver, can I install a CW audio filter and pick up CW. Such as... an IC 207H or BC 780xlt and a Vectronics CW Audio Filter. Thanks FM receivers are designed to not respond to amplitude variations. CW is about as pure an example of "information conveyed by variations in amplitude" as one is likely to find. To cut to the chase, what you propose won't work. That being said, one can send Morse in a format receivable on an FM receiver, but it'll be MCW rather than CW. Feeding a keyed audio oscillator into an FM transmitter will produce MCW. The caveat here is it is legal here in the states only from 50.1 to 54 MHz and above 144.1 MHz. HTH de kg7yy -- The appearance of my E-mail address in any venue does not in and of itself constitute a solicitation of bulk or commercial E-mail. I don't want unsolicited commercial E-mail. |
#4
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![]() "Robert Grizzard" wrote in message ... Matthew and Wendy Plante wrote: Is CW just FM without an audio signal? So, If I have a FM receiver, can I install a CW audio filter and pick up CW. Such as... an IC 207H or BC 780xlt and a Vectronics CW Audio Filter. Thanks FM receivers are designed to not respond to amplitude variations. CW is about as pure an example of "information conveyed by variations in amplitude" as one is likely to find. To cut to the chase, what you propose won't work. That being said, one can send Morse in a format receivable on an FM receiver, but it'll be MCW rather than CW. Feeding a keyed audio oscillator into an FM transmitter will produce MCW. The caveat here is it is legal here in the states only from 50.1 to 54 MHz and above 144.1 MHz. HTH de kg7yy -- The appearance of my E-mail address in any venue does not in and of itself constitute a solicitation of bulk or commercial E-mail. I don't want unsolicited commercial E-mail. So, If I had a receiver capable of AM reception, then a CW filter would work? |
#5
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![]() "Robert Grizzard" wrote in message ... Matthew and Wendy Plante wrote: Is CW just FM without an audio signal? So, If I have a FM receiver, can I install a CW audio filter and pick up CW. Such as... an IC 207H or BC 780xlt and a Vectronics CW Audio Filter. Thanks FM receivers are designed to not respond to amplitude variations. CW is about as pure an example of "information conveyed by variations in amplitude" as one is likely to find. To cut to the chase, what you propose won't work. That being said, one can send Morse in a format receivable on an FM receiver, but it'll be MCW rather than CW. Feeding a keyed audio oscillator into an FM transmitter will produce MCW. The caveat here is it is legal here in the states only from 50.1 to 54 MHz and above 144.1 MHz. HTH de kg7yy -- The appearance of my E-mail address in any venue does not in and of itself constitute a solicitation of bulk or commercial E-mail. I don't want unsolicited commercial E-mail. So, If I had a receiver capable of AM reception, then a CW filter would work? |
#6
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Hello
So, If I had a receiver capable of AM reception, then a CW filter would work? No, then you will need a beatoscillator. No sound is transmitted when you use CW, the transmitter in only turned on and off, so on a AM radio you only hear an interupted carrier and no tone. Regards Max |
#7
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Hello
So, If I had a receiver capable of AM reception, then a CW filter would work? No, then you will need a beatoscillator. No sound is transmitted when you use CW, the transmitter in only turned on and off, so on a AM radio you only hear an interupted carrier and no tone. Regards Max |
#8
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FM receivers are designed to not respond to amplitude variations. CW is
about as pure an example of "information conveyed by variations in amplitude" as one is likely to find. To cut to the chase, what you propose won't work. Sure it will! Open the squelch up all the way. You'll hear the background noise from the band and/or the front-end electronics when there's no carrier being sent. When the OM at the other end keys up, the FM receiver will lock onto the carrier, and happily demodulate the (nonexistant) sidebands - it'll go silent. No CW filter needed... in fact it'd make the noise/silence difference harder to hear. Admittedly, trying to copy "negative noise" CW is likely to be a real hassle at first, but I imagine that one can train oneself to do it (just as one can train oneself to read a book held upside-down). For _conventional_ CW reception, you need something rather different. ;-) -- Dave Platt AE6EO Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
#9
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FM receivers are designed to not respond to amplitude variations. CW is
about as pure an example of "information conveyed by variations in amplitude" as one is likely to find. To cut to the chase, what you propose won't work. Sure it will! Open the squelch up all the way. You'll hear the background noise from the band and/or the front-end electronics when there's no carrier being sent. When the OM at the other end keys up, the FM receiver will lock onto the carrier, and happily demodulate the (nonexistant) sidebands - it'll go silent. No CW filter needed... in fact it'd make the noise/silence difference harder to hear. Admittedly, trying to copy "negative noise" CW is likely to be a real hassle at first, but I imagine that one can train oneself to do it (just as one can train oneself to read a book held upside-down). For _conventional_ CW reception, you need something rather different. ;-) -- Dave Platt AE6EO Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
#10
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On Wed, 23 Jul 2003 11:38:14 GMT, "Matthew and Wendy Plante"
wrote: "Robert Grizzard" wrote in message ... Matthew and Wendy Plante wrote: Is CW just FM without an audio signal? So, If I have a FM receiver, can I install a CW audio filter and pick up CW. Such as... an IC 207H or BC 780xlt and a Vectronics CW Audio Filter. Thanks FM receivers are designed to not respond to amplitude variations. CW is about as pure an example of "information conveyed by variations in amplitude" as one is likely to find. To cut to the chase, what you propose won't work. That being said, one can send Morse in a format receivable on an FM receiver, but it'll be MCW rather than CW. Feeding a keyed audio oscillator into an FM transmitter will produce MCW. The caveat here is it is legal here in the states only from 50.1 to 54 MHz and above 144.1 MHz. HTH de kg7yy -- The appearance of my E-mail address in any venue does not in and of itself constitute a solicitation of bulk or commercial E-mail. I don't want unsolicited commercial E-mail. So, If I had a receiver capable of AM reception, then a CW filter would work? No, with AM reception, you'll just hear the CW signal as a staticky, hashy sound. You need a receiver with a beat frequency oscillator, a BFO, to receive CW with a nice tone. The CW filter has nothing to do with receiving the CW signal, other than narrowing the bandwidth to cut out interfering signals. Bob k5qwg |
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