Best Tuner for Weak OTA and QAM signals?

[Anthony]

I have two HVR-1600 tuner cards. I originally hooked them up to my QAM cable line, but despite what appeared to be decent signal strength, I constantly had problems with glitches, lockups, and crashes.

So, I bought a Philips Indoor HDTV antenna and switched the tuners to the antenna. Better, but still lots of glitchy recordings.

Next, I upgraded to a Channel Master 4221 antenna to replace the desktop antenna. Signal strength is "slightly" higher, but the recordings still skip and stutter a lot.

So, I bought a 10db amplifier to boost the signal. It helps, but the signal strength really isn't much higher than without it. "Most" of my recordings turn out nicely, but every now and then the signal level drops slightly or other interference causes the signal to be all glitchy.

I should point out that I live up on a mountain, only 20 miles from the broadcast antennas, which are all in the same direction. With the antenna and booster amp, the Haupauge Signal Meter usually shows a SNR of 22-25. It was 20-23 without the amp, and around 25-30 on cable. Ironically, cable had the strongest signal, but produced the worst recordings.

My Samsung TV has ZERO problems tuning either the cable or antenna signals, so the tuners in the HVR-1600 are obviously not good at coping with weak signals.

I've thought about getting a stronger amplifier (or adding a second one?), but the current amp doesn't seem to make a lot of difference in the signal strength or the quality of the recordings.

So, I'm curious if there are tuners that work better with weak signals than the HVR-1600? At this point, I think I would prefer a USB tuner so I can try it out without opening up my system again. Of course, it would need to be compatible with GBPVR. I had tried the silicon dust tuner once, but couldn't get it to work at all with my system.

Any recommendations?

Thanks,

Anthony

[bogyver]

I have a Avermedia usb volar atsc tunner that has very high rf sensitvity, I have hade similar problems in the past when I lived in my college dorm. volar worked great in the dorm. On thing you could also try doing is bulding a db4 clone. I had so much trouble getting a good signal to my samsung tv in my dorm that I had to build my own antennas that had better gain than what I could get local.
The volar is about 60 to 70 dollars on newegg and can be had for about 40 if you can find it on ebay.

here is the guide i found on how to build the db2 and later on they mention how to but together two db2's to make a db4. There are alot of other antennas discused in the thread that are good too, its worth the read.
I actualy have built 3 antennas now a db4 clone, a long periodical dipole aray (lpda) and a double loop style, the lpda worked the best, but is really expensive to build, due to making it out of aluminum.

the link sorry I have rambled on to much
http://www.lumenlab.com/forums/lofiversi...613-0.html

[Anthony]

> I have a Avermedia usb volar atsc tunner that has very high rf sensitvity

Does GBPVR support the Volar tuner?

Unfortunately, the Volar doesn't appear to support QAM cable tuning. That's not necessarily a deal breaker, but I have a few digital cable channels I'd like to tune in. Right now I'm tuning the analog equivalents with the HVR-1600.

I'm also not crazy about the little antenna adapter setup. Seems cheap. But, the price is certainly better than the other options.

I'm considering the OnAir GT tuner, which seems to get good reviews. It's rated best tuner in the comparison at http://www.hdtvtunerinfo.com/comparetuners.html

The major problem with the OnAir GT is cost. I've already spent hundreds of dollars trying to get this stuff working, so I'm a little reluctant to just keep throwing money at the problem. And the OnAir GT is a significant cost for "experimenting".

> you could also try doing is bulding a db4 clone.

The antenna I have now is a "DB2" variety and is rated for 30 miles. According to antennaweb.org, all my stations are between 20.6 and 21.2 miles away, between 221-224 degrees.

Combined with the pre-amp and my location up here on the mountain, I should have more than enough signal (The HVR-1600 Signal Monitor averages between 22 and 26 SNR, with a green bar).

My TV has ZERO problems tuning the stations, so the HVR-1600 is obviously a weak link in the setup. I've tried improving the antenna and adding the amp, but it has made very little difference in performance or stability.

I suppose I could try adding another DB2 antenna and combining them, but that would likely introduce other issues. And it all seems like a waste when I'm paying for cable TV to come right to the house anyway (I need it for internet, so dropping cable isn't an option).

Anthony

[bogyver]

Sorry i forgot to mention the volar is supported by gbpvr it shows up as a avermedia a686 in the config

Cant really help you much with the qam stuff.

I though the antenna connector would be cheap as well but its actually strong.

I thought I would mention that I read a review a while back comparing the hvr-1600 to the AverTv Combo PCIE ATSC HDTV and Analog (M780) card that I have as well. The review stated the aver card had better rf sensitivity than the hvr-1600. The volar actually gets better reception than the pcie card. When I lived in the dorms the volar would usualy be getting about 90% signal strength when the pcie card would get about 75%. So I think the the volar would be a improvement if not a big improvement over the hvr-1600 in your case.

You mention that you have tried using an amp to boost your signal, I would caution you about that because some times they can distort the signal so bad that it becomes unitelligable to the tuner. But you probably know that

If you want to add to your db2 I would suggest that you check on the forum I posted to make sure you don't end up canceling out your signal

You mentioned that you have a samsung tv, I have one as well, I would put the volar on par with the sammy's tuner

Hope this info helps and good luck

[flyswatta]

Are you sure it's a signal issue? Just the fact that your TV can tune without a problem and you have a pretty strong signal (after boosting), and that you have the same issue with QAM indicates to me that it may not be a signal issue.

I recently physically reconfigured my setup (moved GBPVR from the office to the living room) and in the process put in a 2 way splitter and another 50' of coax. This resulted in a low signal getting to GBPVR. The symptom that I saw with low signal was that it would record fine for a while, and then wouldn't record at all. Or it just wouldn't record sometimes. There was no middle ground - either it worked or it didn't. I solved the signal strength problem the same way you did, I added a 10db amplifier.

When I was first trying to record ATSC, the biggest problem that I faced was having enough horsepower to playback the recording (hitting 100% CPU). The symptoms were almost identical to what you are describing. The screen would jitter, freeze,hang up, etc. Ultimately, I had to use a better decoder (I used the Nvidia Purevideo decoder, although the ATI decoder worked for me also) that would utilize the hardware on my video card for decoding instead of doing it with the system CPU.

What's your hardware platform? Are you sure it can handle the playback? Maybe you just need to do some tweaking...

[Anthony]

I'm still considering the Volar, as it's closer to my price range. But, I'd still like to investigate options that support QAM as well.

Do you know if two (or three) Volar's can be used on the same system at once?

Are there any problems with USB traffic (printers, etc.) interferring with the data saving to the computer, especially if I install two tuners?

Yep, I read about amplifiers actually making signals worse. I've tried with and without the amplifier, with nearly identical results. The amp adds maybe 1 point to the SNR level, if that. But since I'm splitting the antenna to two cards, I've been using it for now to overcome the splitter losses.

Thanks,

Anthony

[Anthony]

Flyswatta,

> the biggest problem that I faced was having enough
> horsepower to playback the recording

I don't play the videos on my PC, I stream them over my network to a TViX M-4000P in my living room. I have a 3ghz Pentium 4 system, with 512Meg RAM, and a 250gig hard drive dedicated just to video work. Even when recording two digital channels, one analog channel, and streaming a recording to my living room TV, my CPU load rarely goes above 20% or so. So, I don't think it's a system load issue.

> Are you sure it's a signal issue?

No. The fact that I've tried QAM cable and tried multiple antenna and booster configurations seems to indicate something else is at fault. I get basically the same SNR whether I'm using a little desktop antenna or the large DB2 antenna and an amplifier. At this point, the HVR-1600 tuners seem to be the only thing I haven't tried changing.

One of the issues I've noticed is that I can have a strong SNR of 25 or greater, and it'll drop unexpectedly to 18 or lower for a few seconds before jumping back up. This occurs with both tuners, and also occurred with both QAM cable and my OTA antennas. Obviously, the drop in signal usually results in scrambled recordings. If I can keep the signal above 22 or so, everything seems to work OK, but I haven't been able to achieve that reliably over a long time period.

Anthony

[flyswatta]

From what you're saying it does sound like a signal issue. Maybe the guys over at satelliteguys.us in the OTA HD section would have some insight. They thrive on this kind of stuff...

[Anthony]

After researching several options (including the Volar), I just placed an order for an OnAir GT USB tuner. It's $100 more than the Volar, but it supports QAM cable and gets consistant good reviews for reception. I bought it through Walmart.com, so if it doesn't work out I'll be able to return it easily to my local store.

Once it arrives I'll compare it against the HVR-1600 and report back.

If there's no real difference, at least I'll know to continue focusing my efforts on improving my signal.

Thanks Bogyver and Flyswatta for your advice!

Anthony

[bogyver]

I'm still considering the Volar, as it's closer to my price range. But, I'd still like to investigate options that support QAM as well.

Do you know if two (or three) Volar's can be used on the same system at once?

Are there any problems with USB traffic (printers, etc.) interferring with the data saving to the computer, especially if I install two tuners?

I dont see any problems with having two or more volars hooked up to the usb bus, OTA HD take at most 19.39 Mbit/s (from wikipedia) transmision speed. So if you figure that you have 480 Mbit/s on the usb bus and to allow for hardware overhead about 25 Mbit/s for each volar. I would think that there is plenty of spare bandwith. A usb printer even a all in one printer shouldn't even use half of the band with the volar would use.

I wish you good luck with the OnAir GT cant wait to hear how it works for you.