[mythtv-users] Cannot receive 2 muxes (UK)

[Nick Morrott]

2010/1/23 Stephen Kitchener <stephen at g6dzj.demon.co.uk>:
> Hi,
>
> I have a problem - or rather my mythtv set-up has a problem, it cannot
> receive 2 of the 6 mux's in the UK.

Which transmitter are you receiving from, and which muxes are missing?

> I and running Mythtv 0.22 and the video cards are KWORLD /VStream XPert
> DVB-T cards (Zarlink MT352)

I have 3 of those cards in my MBE - they've been rock solid for nearly
4 years now (Sutton Coldfield Tx).

> So here's the information, I have two machines that have the same model of
> DVB-T cards in them, one machine has Mythtv installed the other has not (as
> its new hardware waiting for mythtv installation). On the mythtv installed
> machine, it cannot receive BBC4 on it via mythtv, it gives LMs - Partial
> lock when trying to tune to that station.

When was the last time you rescanned you channels? What version of
MythTV are you currently running? Are you in a region of the UK that
has undergone Digital Switch Over (DSO)?

> On the new machine I decided to check to see if the problem was the same on
> that, but this time via vlc, to my surprise I could get BBC4, so back to the
> original Mythtv machine and I installed vlc there also, and now I could get
> BBC 4 correctly, but I still could not get BBC4 via mythtv. Each of vlc and
> mythtv are tuned to the same mux frequency, so my question is, is Mythtv
> more picky in what it will display, or is vlc more lackadaisical in its
> criteria for display.

Are you using quick tuning for recordings/LiveTV? If so, turn it off
and see if it helps.

> And more importantly what can I do about it ??

If vlc on the mythbox gives you perfect digital TV, your DVB card is
performing adequately and your cabling is providing a strong enough
signal to not warrant checking upstream of your DVB card's RF input in
the first instance.

You could run scan (or your distro's equivalent DVB scanning tool)
with a mux config file for your local transmitter, and compare the
channel settings in the resulting channels.conf file with your MythTV
channel settings (using the channel editor in mythtv-setup or
MythWeb).

You can also increase the logging verbosity (backend logfile) to
include "channel" as that may give more useful debug info.

> I did read somewhere that on some digital cards there is a option for
> switching on an on-board pre-amp for the signal, but I have no information
> about this for this card.

The Nova-T 500 has an onboard LNA that can improve signal strength,
but I don't think the Xpert cards do.

Cheers,
Nick

-- 
Nick Morrott

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