[mythtv-users] Can't tune after UK switchover

[David Watkins]

On 14 July 2011 10:50, john legion <johnlegion6 at gmail.com> wrote:
> Hi All,
>
> I am in Edinburgh and previous to the digital switchover I was able to see
> two transmitters, Blackhill and Craigkelly.
> Subsequent to the switchover I can no longer get  Mythtv to lock onto any
> channel on either transmitter.
>
> When I retuned I could see most multiplexes on both of the transmitters but
> not all.
> I have tried tuning using full scan in Myth, scan of existing transports,
> scan of existing transports where I had manually edited the transports to
> only include the few I would need and also by importing channels.conf .
>
> All of these methods according to Mythtv have found >100 channels and so
> everything seems good but when I go into the frontend then I can't watch
> live TV because the channel never gets past partial lock, even though the
> signal strength is ~75% .
>
> Also , no matter what I do I can't see any EIT data on any channel .
>
> With the ariel connected directly to my TV I can see all channels and EIT
> data. I can also play tv through Xine on the backend server so I guess that
> the ariel and card are working, it just seems to be some issue with Mythtv.
>
> Is anyone else seeing the same or does anyone have any suggestions ?

I'm only guessing but:

1) Are you using an aerial amplifier or amplified splitter?  Digital
signal strength may have increased significantly following switchover
and it's possible you're saturating the capture card input.  I live
quite close the Crystal Palace transmitter and have to use an
attenuator with one of my capture cards.

2) It's also possible that, if the digital multiplexes have changed
frequency,  your antenna is no longer suitable.  As I understand it,
DVB multiplexes can use channel frequencies within the analog TV
channel range, in which case an old 'analog'  antenna will work fine,
or use frequencies outside that range, in which case it may not work
so well.

3) It's also possible that, now the broadcast power has been
increased, your two transmitters are interfering with each other and
you need a more directional antenna.

I'd hope for option 1 if I were you!

Good Luck.