Re: RF cable i mono?

"weitrhino" <[EMAIL PROTECTED]> wrote:

> Someone told you wrong.
>
> Coax is only mono IF the source is mono or when a VCR is active as the
> tuner.  A VCR essentially breaks down the RF signal into its parts, audio L,
> audio R, and video.  If coax is used to port the audio and video to the TV,
> then the sound will be mono.  If the VCR is turned off allowing the RF to
> pass through unaltered, then the sound will be stereo if the source is
> stereo.

To be more specific:

All stereo VCRs (those with Hi-Fi audio recording/playback capabilities)
include MTS encoders, and will ALWAYS pass stereo from their RF inputs to
their RF outputs.

MOST mono VCRs (those without Hi-Fi audio recording/playback capabilities)
do not include MTS encoders, and thus MOST will ONLY pass stereo from their
RF inputs to their RF outputs when they are in TV mode (i.e. when their
"VCR/TV" modes are switched to "TV").  (When a VCR is in "TV" mode, their
tuners do not demodulate and then remodulate the channel you're watching
to channel 3; they simply pass everything through to the RF output gratis.)

Cable boxes are a different matter.  Some will pass stereo (those with MTS
encoders in them), others will not.  There is no rule as to which will and
which won't (such as the era of their manufacture).  For example, my city
has had Zenith PZ-1 and Scientific Atlanta 8510X analog boxes, and both of
them included MTS encoders and thus generated stereo on their RF inputs.
However, our brand new Motorola DCT-2224 digital boxes do NOT have MTS
encoders in them!  So, you only hear stereo on their RF outputs when they
are tuned to unscrambled analog channels (in which case they're simply
hetrodyne downconverting those channels to channel 3, but not demodulating
and then remodulating them).  In order to hear stereo 100% of the time with
DCT-2224 boxes, you must use the left/right audio outputs on their rears.

All of this comes down to manufacturer penny-pinching.  MTS encoders are
necessary for stereo to pass out of a device that demodulates an NTSC RF
carrier.  Many manufacturers simply assume consumers will never notice the
difference between stereo and mono, and avoid adding the necessary MTS
encoders for assuring 100% stereo passthrough.