[mythtv-users] DVB-T Hell in Sydney

[Doug Scoular (dscoular)]

Hi All,
	There's been an interesting development in my 0.28 DVB-T drama... but
first let me answer some of the replies I've received.

mikep wrote:
> To mention the obvious, have you checked that the transmitter is
>actually working? Have there been
> changes in frequency allocations, transmitter power levels or maybe
>there is scheduled (or
> unscheduled) maintenance going on?


and perkins1724 wrote (possibly the same person):
>
> Are you sure you are on the correct transmitter? This site lists a
>completely different set of frequencies for Bouddi.
>
> https://ozdigitaltv.com/transmitters/NSW/32-Bouddi

	Well, in my email my focus was really on the fact that external to
mythtv, tzap is still able to get lock on any channels that show up in a
scan. Prior to this I had suspected something had happened to my antenna
or the transmitter. That told me that at least some of the channels were
okay.

	There is very little status information to be had from any of the digital
broadcasting sites I could find through google. I did stumble upon the
exact link you quoted above and I also noticed that the frequencies quoted
were quite different to those provided in the Ubuntu 16.04 /usr/share/dvb
initial scan files for au-Newcastle. I even created my own initial tuning
file with the frequencies I found... but none of them would get lock. I
have no clue how to determine which transmitter is actually in use other
than by the general direction the antenna is pointing in. However, read
on...

	I then had a brain-wave, I still had my April 23rd version of mythbuntu
14.10 and mythtv 0.27 sitting on my /dev/sda2 partition. That was the date
I decided to bite the bullet and upgrade to 0.28... I was super impressed
at how smoothly this went at the time. Anyway, I rebooted in to 14.10
running 0.27 and found that all networks and all their respective channels
work! There's nothing wrong with the transmitter, antenna or the quad
shielded cable. Scans on 0.27 don't show Southern Cross Ten or Seven etc.
but tzap will happily get lock on all of them as will mythtv 0.27.

	I cannot just revert back to my April 23rd 0.27 as there have been way
too many episodes of Masterchef recorded :^) and I assume my database
schema evolved somewhat when going from 0.27 to 0.28.

	0.28 *was* working perfectly on all channels till the end of May.
Something, maybe through an auto-update, changed and suddenly 0.28
couldn't tune to any channels (and tzap could only tune to a limited
subset even when using old channels.conf files).

	My plan is to reboot in to 0.27, export my channel and dtv_multiplex
tables and reboot back into 0.28. I'll backup my 0.28 mythconverg
database. Delete all 0.28 channels, try a rescan (no doubt losing Seven,
Southern Cross Ten, and possibly, ABC in the process) and see if mythtv
0.28 is able to get lock again. If that succeeds I'll try hand merging my
other 0.27 channel and dtv_multiplex tables back in.

	The worrying aspect is the fact that tzap under 14.10 can tune to all
channels but under 16.04 it could only tune to channels that had shown up
in a scan. It's a real puzzler. I'm also surprised that under 14.10 and
0.27 I can get lock on channels via tzap that do not show up in a scan.

	I'll try and update this thread when I can make a comparison of the 0.27
dtv_multiplex/channel tables and the 0.28 ones currently buggered.

	Again, any thoughts or insight as to why this might of happened much
appreciated.

	Cheers,

	Doug

	"The big print giveth and the small print taketh away..."