[Lowfer] Growling audio on MWBC signals

[C. Turner]

Slightly OT, but interesting nonetheless:

Some weeks ago I happened to tune in our local 69 horsepower (formerly) 
"clear channel" AM radio station (1160 kHz - KSL) and upon listening to 
it in SSB mode using exalted carrier methods, I heard a rather obnoxious 
growling on the audio that disappeared when "normal" AM or synchronous 
AM techniques were employed.

Upon inspecting the carrier, I noted that there was a pair of 16 Hz 
sidebands responsible for the "growling."  Curious, I asked the 
engineer, Randy, K7SL - who I happen to know - and here is an excerpt of 
his response:

"16Hz is a low speed data stream used to send messages to warranty 
receivers.  These guys are battery operated 10 year lifetime receivers 
that attach themselves to things like Baby Cribs, Saws, etc.  These 
receivers set off alarms if a factory recall happens.  They then give 
details for the recalls.  The data also contains clock correction 
signals for home user clocks.  The clocks currently using WWVB don't get 
a good enough signal inside noisy environments and the 50kW signal from 
KSL and other Clear Channel stations cover the the US better.

"Currently the signal ...  is just a test signal that repeats itself. 
  If [one] looks at night on other strong AM stations [you] will see 
similar signals. There are other uses for the signal, but I don't 
remember them right now.  All I know for sure is that it eats up a lot 
of transmitter power.  Of course any 1/2 db added to the modulation 
looks like it is stealing all the power when you look only at modulation 
levels around 95 to 100% (chuckle).

"A word of warning.  If you walk too closely to one of these receivers, 
it might un-attach itself from where it is and jump to the back of your 
neck and re-attach itself to you.  It will then give Aliens control of 
your mind and you know what happens from there.  [I saw this on TV so I 
know it is true]"

So there.

I wonder how long it takes before conspiracy-minded people consider this 
to be a means of mind control?

(Never mind...  too late!)

73,

Clint
KA7OEI/CT