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Author Topic: Receiver licensing?  (Read 5643 times)
AA4HA
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Posts: 2456




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« Reply #30 on: February 17, 2018, 11:19:53 AM »

A strange area where you will still find a very proprietary and little known type of radio "licensing" is with SCA (Subsidiary Communications Authorization) broadcasts in the FM radio band.

These are carriers that are piggybacked on top of normal FM broadcast signals but are offset far enough away from the center frequency that most radios do not demodulate the signal. They are commonly used for reading services to the blind or secondary language broadcasts (like the news being read in Polish or Chinese). Also there are some data services that use SCA signals for broadcast. The SCA signal may be offset by 50-100 KHz (commonly 67 KHz)

While there is nothing specific that denies you the right to access an SCA signal the receivers are made by very few companies (Metrosonix being one) and quite often they are leased for paid services (like the now defunct Physicians Radio Network or stock reports).

I have a Norver Co Inc SCA receiver that only has their company logo on the front of it. It does not have the standard "receiver for the deaf, property of XYZ radio station" that many of them are labeled with. Many were not supposed to be resold but instead were loaned out and meant to be returned to the station for re-issue when no longer needed.
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In a way you might think that Sirius/XM are a form of licensed receiver. They do nothing useful without you paying for the service to activate the radio through their satellites.
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Ms. Tisha Hayes, AA4HA
Lookout Mountain, Alabama
Free space loss (dB) = 32.4 + 20 × log10d + 20 × log10 f
K1ZJH
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Posts: 3572




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« Reply #31 on: February 18, 2018, 08:03:02 PM »

Vectronics sells a simple kit that can be added to a FM radio for SCA decoding.  SCA is mostly found on PBS stations these days


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WA2ISE
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Posts: 1074




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« Reply #32 on: February 19, 2018, 10:49:19 AM »

I posted just yesterday in the SWL subforum how to use your HF transciever (one that can do FM down to 30KHz) to listen to SCA subcarriers.  There's nothing that interesting to actually listen to, but it's more for the fun of doing it. 
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