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#11
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I also live in the area and we get SCA transmissions from NYC and Philly.
Lots... readings from the NYT, WSJ, different languages, and digital. The best directory is Bruce Elving's guide. Joe "DougSlug" wrote in message ... I am in the Trenton area, not far from you, Doug...what SCA programming, if any, have you discovered at your location with this radio? - Doug "r392" wrote in message news:hz2Kd.11237$Dz2.457@trndny09... I bought a SCA radio AM FM radio with the upper and lower SCA setting for cheap on Yahoo auctions about a month ago brand new in box here is a link. I do not have anything to do with the guy just thought it was a good deal. the radio is a cheap radio. It has good audio and great sensitivity. for $30 well worth it. Doug |
#12
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Cannot be done with sound card or software. These are subcarrier s in
the FM signal. One has to tap the receiver after the demodulator and send through a separate LF FM receiver ("adapters"_. Note that there are legalities to consider in the US. ---------------------------------------------------- hmm.... new question I'm now wondering about after reading the above. Does this mean that any audio tape I recorded years ago of regular FM stations that happened to broadcast subcarriers also have the subcarrriers recorded on my old tapes???? And if I was able to buy an SCA decoder, I would be able to hear these old SCA transmissions when listening to my old audio tapes? or would my old audio tapes only have the regular FM station information recorded on them, even though the FM station was broadcasting a subcarrier that I was unaware of at the time? |
#13
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Note that there are legalities to consider in the US.
--------------------------------------- strange. I've seen SCA decoers at legal ham radio stores just last year (2004), and the hams say that hams never do anything illegal. That hams always obey the law. Thereforem how can it be illegal if hams never do anything illegal and sell them to customers at legitimate stores? |
#14
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![]() wrote in message ... Cannot be done with sound card or software. These are subcarrier s in the FM signal. One has to tap the receiver after the demodulator and send through a separate LF FM receiver ("adapters"_. Note that there are legalities to consider in the US. ---------------------------------------------------- hmm.... new question I'm now wondering about after reading the above. Does this mean that any audio tape I recorded years ago of regular FM stations that happened to broadcast subcarriers also have the subcarrriers recorded on my old tapes???? No. It is certain that your recordings recorded frequencies of centered at 67 and 92 kHz where SCA is centered. Audio frequencies stop at about 18 kHz and your recording do also as did the audio output of your receiver. On the other hand, an old Beta video recorder could be modified and hooked to the FM demodulator to do what you describe. or would my old audio tapes only have the regular FM station information recorded on them, even though the FM station was broadcasting a subcarrier that I was unaware of at the time? Yes. |
#15
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![]() wrote in message ... Note that there are legalities to consider in the US. --------------------------------------- strange. I've seen SCA decoders at legal ham radio stores just last year (2004), and the hams say that hams never do anything illegal. That hams always obey the law. Thereforem how can it be illegal if hams never do anything illegal and sell them to customers at legitimate stores? Listening to SCA has nothing to do with ham radio. And also, selling the equipment is not a legal thing. If is what a person does with it that involves legalities. You can buy SCA decoders, but you can legally only listen to what you have permission to do nmaking some purchases for legal purposes. Yes, there is a reallity gap--some laws are simply stupid. Similarly you used to be able to buy scanners that could receive cell phones. It was illegal though to do that. |
#16
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You're correct that the audo tapes would only have audio information, but
the SCA information is also in the baseband signal except that it's outside the audio bandwidth that the tape recorder would have recorded due to AF filtering in an ordinary FM receiver. As I understand it, the SCA information is filtered from the demodulated signal before it is sent through the AF filter normally used for the audio output of the "main" (primary carrier) baseband signal. "Bob Horvath" wrote in message ... On Fri, 11 Feb 2005 03:01:21 -0500, Bob Horvath wrote: Your tapes would only have "audio" information on them, not Radio Frequencies, which is what contains the SA information. |
#17
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![]() "DougSlug" wrote in message ... You're correct that the audo tapes would only have audio information, but the SCA information is also in the baseband signal except that it's outside the audio bandwidth that the tape recorder would have recorded due to AF filtering in an ordinary FM receiver. As I understand it, the SCA information is filtered from the demodulated signal before it is sent through the AF filter normally used for the audio output of the "main" (primary carrier) baseband signal. It is filtered out by the Stereo demultiplexer before it gets to any audio stage. To receive SCA, you will need to tap into the receiver after the product detector (discriminator, pll, whatever) and before it goes to the demux. An SCA receiver is effectivily a 67khz receiver plugged into your 100MHz receiver. There is a LOT of info out there from people doing the same mod for the purpose of receiving data/pager transmissions. Search under " discriminator tap" and see what comes up. Nana |
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