Re: RF cable i mono? - Corrections

I wrote:
>
> "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.)

Also: as weitrhino said, mono VCRs (those without Hi-Fi) also pass stereo
when they are turned off.  So do stereo (those with Hi-Fi) VCRs.

> 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.

Correction: on their RF outputs.

> 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.