[mythtv-users] PRV-500 Quality inconsistancy

[John Drescher]

> I recently added a second PVR-500 to my system and I'm seeing poor recording
> quality on the second unit.  As you can see, one of the cards features
> Philips tuners, while the other features a Samsung unit.  My older card,
> which has the Phillips Tuner seems to record well, while the newer one with
> the Samsung Tuner yields grainy video with diagonal lines.  This seems true
> for both tuners on the card.  Is this just a limitation of the hardware, or
> is there something I can do to improve my results?  I'm using the cards with
> my MythTV system, running version .20.2.  I'm confident the coax cables are
> not the issue, as my new PVR-500 card replaced a PVR-250, which was
> connected by the same cable.  I can switch the two lines between my two
> installed cards and there is no change in the results, the older card works
> well and the newer one does not.
>
I assume you have a kernel version higher than 2.6.18. Before that
version the LNA was off.

Search the ivtv-users list for Samsung LNA. The problem is the LNA
(low noise amplifier) is a very poor quality amp on the samsung units
and they are very sensitive to input levels. I have the same card and
after playing around with the inputs (significantly reducing the input
signal seems to help) for months I ended up replacing the card with a
pvr150 and all is well since.

My pvr 500 now functions as a paperweight on my desk but I guess it
will be useful for composite input if I end up upgrading my cable
service to digital...

John