Poor analog cable reception on various tuners

[jtw29]

I've been using dual HVR 1600s for quite a while now for OTA HDTV and it's been working great. But now I'm in a new house and have cable now. Comcast in Fairfield CA. Digital QAM channels tune great. But there are a few channels I get on analog but not digital and the analog cable is really crappy using the tuners in my HTPC. If I connect the cable directly to my TVs built-in tuner, analog pictures are crystal clear so I know the signal is strong enough to give a good picture. I thought that my HVR 1600s just had poor analog reception and tried two other usb stick tuners and both have the same problem. Poor analog reception. I even tried adding a signal booster. No luck. Is this some kind of know issue with analog signals and pc tuners? And please don't just tell me about the difference in quality between digital and analog. I already know that and recognize that this problem goes beyond that.

The tuners I've tried are Hauppauge HVR 1600, AverMedia AVerTV Hybrid Volar Max (H826), and Hauppauge HVR 950Q.

I'm using Windows 7 64 bit.

Suggestions would be greatly appreciated.

Thanks!

J

[GKusnick]

By poor reception do you mean noise, interference, ghosting, signal dropouts, and so on? Those would be signs of a weak signal.

Or do you mean stable reception but poor image quality? I.e. grainy, dim, bad contrast, artifacting? That could indicate a problem with your encoder settings. What recording quality and bitrate are you using? Have you calibrated the tuners to your analog cable signal?

Your decoders and graphics drivers could also play a role in how the analog SD content is upscaled to fill your screen. More information on how you have that configured might help in narrowing down the problem.

[jtw29]

By poor quality I mean noise, interference, image bending and warping at the top. Very typical of some kind of interference, weak signal, or just plain bad reception. The wierd thing is that if I connect that same cable feed directly to my TV's built-in tuner, the picture is great. I'm not sure what could be causing the problem.

J

[jtw29]

I haven't done any "calibrating" of the tuners to the analog signal. I wasn't aware of the option to do that. Can you tell me more about that? I did a channel scan but that's it.

J

[GKusnick]

There's a screen somewhere in Source Setup (I don't recall exactly where since all my tuners are digital) that lets you adjust brightness, contrast, color balance and so forth for analog encoders. But these are image-quality settings that control how the analog signal is digitized after it's been received; they don't affect your ability to tune in a weak signal.

The usual remedy for weak cable signals is to minimize the number of splitters between the cable demarc box (the point where it enters your house) and your tuner. Some dual tuners have internal splitters that attenuate the signal further. If you need to use an RF amp, put it upstream of any splitters, to boost the signal before it gets split; all splitters introduce noise, and you don't want to be amplifying that.

[Fuzzy]

It's also entirely likely that your signal is actually TOO strong. Either way, the cable company SHOULD make sure you have proper signal strength (meaning not to strong, OR too weak). This is usually done by measuring the strength in your home, and adjusting the attenuator at the curb. For a new customer, this SHOULD be a part of the 'installation', but then again, when have providers ever done what they 'should'.

[robmarch]

Originally Posted by jtw29

By poor quality I mean noise, interference, image bending and warping at the top. Very typical of some kind of interference, weak signal, or just plain bad reception. The wierd thing is that if I connect that same cable feed directly to my TV's built-in tuner, the picture is great. I'm not sure what could be causing the problem.

J

I have the same problem with one of my tuners (but not the other). the working tuner is a pvr150, the non working is the analog side of an hvr 1600.

I've tried several things, including rolling back firmware, swapping analog feeds between the tuners, boosting the tuner's signal, dropping the tuner's signal, etc., and haven't found anything that eliminates the image distortion at the top of my picture with the card.

Interestingly, this just cropped up as an issue a few months ago, previously the card tuned analog signals with no problems. I thought the problem only happened in sage, but I can now replicate it in wintv too.

[jtw29]

Yesterday I kind of narrowed down the problem a bit but I'm still not sure what the solution could be. I went ahead an installed the full software suite for the AVerMedia tuner (I had only been using the driver before) and found that their channel scanner found all the channels with great picture quality. So, I know the tuner is receiving a good signal and is capable of producing a good picture. However, when I do a channel scan in SageTV (latest beta version of 7) it only recognizes a few channels and they're all messed up (noise, distortion, etc.). So, I'm thinking it's more of a SageTV issue than a hardware issue. Anyone have any other ideas? If not I'll probably re-post this in the beta discussion area.

J