Talk:Subsidiary communications authority

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"If you own a shortwave radio that tunes below 100 kHz, and will demodulate FM, it can be used to listen to SCA broadcasts. Just tune your FM radio to the station, tune your shortwave radio to either 67 kHz or 92 kHz (in FM mode), then feed the baseband audio into the receiver's RF (antenna)input to de-code the signal"

This statement is problematic and should be removed entirely. Most stations that broadcast SCA will also broadcast in stereo. This will activate the stereo decoder circuitry in the FM radio and cause the demoulated signal to be fed through a low-pass (15KHz) and de-emphasis filter, removing any presence of a 67KHz modulated SCA carrier from the audio. The setup described may work with a stricly mono FM receiver, but then this should be noted.

Fixed Altaphon (talk) 19:03, 15 April 2011 (UTC)
Considering that the Short Wave band is between 3 MHz and 30MHz, you will be hard pushed to find a short wave radio that tunes that low. What you require is VLF radio (very low frequency) as those frequencies are even below what is regarded as Long Wave. (talk) 12:37, 29 September 2011 (UTC)


Removing the following section per WP:NOTHOWTO. Wikipedia is not a "how-to" guide.

It's possible to also receive the SCA/SCMO signal using a radio that is able to
tune and demodulate signals below 100 kHz in FM mode. In that case, the
baseband audio (recovered from the discriminator of the FM receiver before
multiplex decoding or filtering) is fed into the receiver's RF (antenna) input
and the radio tuned to the subcarrier frequency (typically between 53 and
94 kHz, 67 and 92 are common) to extract the signal's contents.
Alternatively, the baseband audio before deemphasis can be heterodyned with a
suitable IF (intermediate frequency) (that is in the range of the receiver's
ability to demodulate FM) and fed into the receiver (tuning it to the
appropriate frequency in that case) or even fed directly into the demodulating
stage (provided one has the technical knowledge required).

— Preceding unsigned comment added by (talk) 22:25, 2 February 2014 (UTC)