[Scan-DC] Sig Quality - TV Converters

[Jeff Krauss]

8VSB is a modulation method and for 8VSB, multipath tolerance is 
determined primarily by the equalization capability of the tuner in 
the receiver.  Each generation of tuner chip sets has performed 
better than the previous generation.
There are tradeoffs between different modulation methods.
Other modulation methods for digital TV might permit better multipath 
performance but have worse noise threshold, for example.
APCO-25 isn't comparable because it's designed for two-way narrowband 
voice rather than broadcast video.


>----------------------------
>Message: 8
>Date: Fri, 27 Feb 2009 08:16:38 -0500
>From: "W4NNG" <w4nng at soalex.us>
>Subject: Re: [Scan-DC] Sig Quality - TV Converters
>To: "Scan DC" <scan-dc at mailman.qth.net>
>Message-ID: <EFFB999D2DA8427A8DD9F485C5BCA104 at d30>
>Content-Type: text/plain;       charset="iso-8859-1"
>
>Most likly signal quality is the BER (bit error rate) and yes multipath,
>especially when it's shifting would increase BER.
>
>I wish I understood the ACPO-25 techniques better for handling shifting
>multi-path, but 8VSB is probably the least tolorant of the major decoding
>schemes in use today.  According to an  IEEE report I saw some years ago
>they indicated that of all the DTV scheames used world-side 8VSP was the
>least tolorant of MP.