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View Full Version : Different tuning/different snr. Picture quality locked until re-tune



tonycollinet
December 28th, 2010, 02:02 PM
Hi

Myth 10.10
Nova T 500 dual tuner card
LNA's enabled.


Ever since I installed Myth a couple of years ago (9.1) I've had problems with signal quality. I am now on 10.10 and still having them.

I decided to sort it out, and have been doing some experimentation today. Tuner is NovaT 500 with dual inputs. I first noticed that one of the two tuners had significantly more signal strength (I was only connecting one of the inputs)

So I've bought a 4 way distribution amplifier, and am driving both inputs. However problem remains - and it is strange. I've narrowed my experiments down to one channel (Dave) because it shows the problem most consistently.

Basically one tuner is OK all the time (I think). The other - I can tune it to/from Dave. If I get an SNR of 2.4, then the picture is bombproof. If I get 2.3, then I get some glitches. 2.2 and below and it is unwatchable. (The SNR is only displayed at the time of tuning)

However, here is the weird thing. If I was getting variable signal quality, then you would expect the picture quality to vary as I am watching it, but that is not the case. Once it has tuned in with a particular SNR, then the picture quality stays good - or crap - however it started. It will only change if I select another channel and then go back to Dave.

So clearly - myth is setting something differently at the time of tuning. Is it possible the LNA's (LNA's are enabled) are enabled dynamically - and sometimes they are switched on, others off?

Or can there be some other explanation?

Thanks for any help.

newlinux
December 28th, 2010, 04:28 PM
Are you sure it's myth and not the tuner card itself? Have you tried using to card outside of myth?