[mythtv-users] no channel lock - live TV

[Jay Summet]

I'm going to assume you are using a HTDV tuner, with an Over the Air
(OTA) antenna.  (Because that's what I have...)

I ran into this problem with weak signals. MythTv has a setting (I think
it's in the backend, and you have to use mythtv-setup to access it) for
how many MS/seconds to wait before giving you the error message. By
default it is around 2 or 3 seconds. I upped mine to 5 seconds and for
those hard-to-tune channels it would allow my Silicon Dust HDTV tuner to
lock onto the channels before Myth gave the error message. So try making
that timeout longer and see if it helps.

Bigger picture, if a weak signal is indeed your problem, you need to
improve the signal. (I live close to transmitters, but had the problem
when trying to use an indoor antenna. As soon as I mounted the antenna
outdoors, the Silicon Dust box locked onto signals much faster.)

Side Note: You can get a signal that is TOO STRONG! If you live near a
transmitter and have a good outdoor antenna, you can get a signal with
100% signal strength, but that suffers from noise (due partially to
multi-path reflections, and partially to the fact that the signal is
overpowering the tuner).  This will exhibit itself as a channel that
tunes in quickly, but sometimes has "glitches" when the SNR drops to
20-30% range (while the signal strength remains at 100%).  So, if
anybody has great reception (100% signal strength on all channels) but
is suffering from glitches on one or two of the channels, you may
actually want to weaken your signal!  I did this with a 16db attenuator.
(I bought various attenuators: 3, 6, 10, and 16db and it turns out that
the 16db attenuator worked the best! I wasn't expecting to have to
attenuate the signal that much!) I can still receive all of the channels
I had before, and the glitches have disappeared from the one that was
causing me problems.

Jay



Nick Petrik wrote:
> Hi All,
> 
> I have seen many posts about this issue but no answers that would help me to get this issue solved. 
> 
> I have successfully scanned the channels using MYTHTV. I also know that the card works because it works with other progs such as kaffeine.
> 
> But everytime I want to watch live TV in Mythtv I get the message telling me that I should have got a channel lock by now. Nothing more. Is there anything I might have missed? Thanks for your help / Nick

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