[mythtv-users] HDHomerun Quatro and Duo demodulator issue

Gary Buhrmaster gary.buhrmaster at gmail.com
Fri Dec 7 00:12:41 UTC 2018

On Wed, Dec 5, 2018 at 11:07 PM James Abernathy <jfabernathy at gmail.com> wrote:

> So at least there’s hope of getting this fixed in firmware.

There always was.  From memory, it is Maxlinear that
provides the tuner/demod chip (MxL692), and they have
seen something similar before with some previous gen
chips.  In fact, there was apparently a minor firmware
update for the tuner./demod in the 20171208 update
(the description was "Fix problem where channels may
fail to tune") that improved some cases.  In any case
you likely do not have the OEM contract to be able to
talk with MaxLinear directly (SD does) so the entire
process takes time to work through (most importantly,
any change in demod firmware has to go though *very*
long analysis/testing to insure it does not impact different
customers and different broadcasters adversely;  there
is actually a known issue with some broadcasters and
some specific old MaxLinear demods where the station
engineers were known to be different and decided to
terminate a specific port on their transmitter equipment
result in various decoding artifacts), even after it was
pointed out to them (station engineers tend to be very
conservative about changes, and they mostly care
about whether the Samsung/Sony TV's continue to
work, and other devices do not count, so one has to
test, test, and test before making available new firmware).

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