[BC] FM Band other used for 19 kHz.
DANA PUOPOLO
dpuopolo
Wed Jan 18 07:07:29 CST 2006
PLL stereo decoders (the ones used for the past 30 years - like the MC1310 and
LM1800) can lock onto as little as 4% pilot. If I had my say, pilot injection
would be cut by 5% (to 5%) and the additional modulation used to increase
program loudness.
-D
------ Original Message ------
Received: Wed, 18 Jan 2006 05:00:15 AM PST
From: DHultsman5 at aol.com
To: broadcast at radiolists.net
Subject: Re: [BC] FM Band other used for 19 kHz.
Ok Brain trust I have several questions. What can we technically use
10% of the FM signal at 19 kHz. for other than light the stereo light (not
primary) and phase locking the 38 kHz. DSSB suppressed carrier?
I have heard several ideas in the past, Frequency shift keying for data? By
adding a time constant to hold the receiver phase while the 19 kHz. is
shifted + or -.
I have heard discussion of amplititude modulating the 19 kHz. low response
with no cut off below 2% modulation for telemetry tones.
Since it was such a small amount of bandwidth and % of modulation. Think
about it. It seems that we are wasting 10% modulation when the receivers
could be locked with todays technology.
I doubt that it will ever be changed but I wonder if you could do something
similiar to RBDS on the 19 kHz?
Think out of the box.......Comments and ideas???
Dave
hanging out in Pittsburgh
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