QAM, HVR-1600, Amplifier?

[dennit]

I'm trying to set up GBPVR with a Hauppauge HVR-1600 to receive and record QAM digital channels. When I scan the channels, I don't find/get all the QAM channels that my new HDTV can find. The HDTV has a signal strength meter and the channels not found by GBPVR are the weaker channels. The TV says the signal strength is near 10 for some channels (scale of 10) and near 3 for others when I bring the cable straight to the TV.

Unfortunately, I need to split the cable for other devices, and when I do that the signal remains near 8-10 for the strong channels, but drops to around 1 for the weak ones. (I haven't tried bringing cable straight to the HVR-1600 yet). I notice that during rain, the weak channels tend to drop out.

OK, the obvious answer was to buy an amplifier. I tried 6 different amplifier models! They ranged in price from $25 to $130 and in style from single output to 8 outputs. Every single one produced a DECREASE in signal strength measured by the HDTV as compared to the unsplit cable. I'm comparing bringing the unsplit cable directly to the TV from where it enters the house vs bringing it directly to an amplifier under test, then straight to the HDTV. The weak channels would measure 3 without the amplifier and 1 with the amplifier in-line!

I know this isn't directly a GBPVR question, but can anyone make any suggestions for me? Surely there is some way to get a strong signal from the point where the cable enters the house to other points in the house.

Unfortunately, two of the channels I really want to record are weak ones, so I think I need to get this problem sorted before going farther. BTW, the WinTV scan has the same problem with these weak channels - it doesn't find them. They look fine on the TV, particularly with the direct cable feed, but occasionally drop out or stutter when split/amplified.

The amps seem to help the analog cable. The amps varied between 900 mHz and 1000mHz top end. I'm pretty sure that my cable system is below that.

Thanks for any help or guidance.

[pastro]

I'm trying to set up GBPVR with a Hauppauge HVR-1600 to receive and record QAM digital channels. When I scan the channels, I don't find/get all the QAM channels that my new HDTV can find. The HDTV has a signal strength meter and the channels not found by GBPVR are the weaker channels. The TV says the signal strength is near 10 for some channels (scale of 10) and near 3 for others when I bring the cable straight to the TV.

Unfortunately, I need to split the cable for other devices, and when I do that the signal remains near 8-10 for the strong channels, but drops to around 1 for the weak ones. (I haven't tried bringing cable straight to the HVR-1600 yet). I notice that during rain, the weak channels tend to drop out.

OK, the obvious answer was to buy an amplifier. I tried 6 different amplifier models! They ranged in price from $25 to $130 and in style from single output to 8 outputs. Every single one produced a DECREASE in signal strength measured by the HDTV as compared to the unsplit cable. I'm comparing bringing the unsplit cable directly to the TV from where it enters the house vs bringing it directly to an amplifier under test, then straight to the HDTV. The weak channels would measure 3 without the amplifier and 1 with the amplifier in-line!

I know this isn't directly a GBPVR question, but can anyone make any suggestions for me? Surely there is some way to get a strong signal from the point where the cable enters the house to other points in the house.

Unfortunately, two of the channels I really want to record are weak ones, so I think I need to get this problem sorted before going farther. BTW, the WinTV scan has the same problem with these weak channels - it doesn't find them. They look fine on the TV, particularly with the direct cable feed, but occasionally drop out or stutter when split/amplified.

The amps seem to help the analog cable. The amps varied between 900 mHz and 1000mHz top end. I'm pretty sure that my cable system is below that.

Thanks for any help or guidance.

What type of RF cables are you using? Are there any splits outside of your house?

I use two amps in my setup. One the cable company supplied and one is a radio shack remote powered amp.
The cable supplied amp gives 15dB signal improvement and the radio shack 10dBs as measured by my cable box.


That said that does not neccesariliy translate to an SNR gain at your TV. Typically I need about 32dBs to get good digital reception. Maybe the signal meter is actually an SNR meter which might react as you are seeing.

Also, for a single split and short cables afterward, chances are you won't get any SNR gain with an amp. You really need that amp as far upstream as possible.

Do you have a settop box and can you put it in diagnostic mode and dump out the signal level and SNR?

[dennit]

What type of RF cables are you using?

RG6

Are there any splits outside of your house?

No

Also, for a single split and short cables afterward, chances are you won't get any SNR gain with an amp. You really need that amp as far upstream as possible.

I could try moving the amp right to the house entrance. Previously, I ran a cable from the house entrance to near the TV, then through the amp. What confuses me is that the signal drops after it goes through the amp, and the signal is weaker.

[pastro]

RG6



No



I could try moving the amp right to the house entrance. Previously, I ran a cable from the house entrance to near the TV, then through the amp. What confuses me is that the signal drops after it goes through the amp, and the signal is weaker.

That doesn't make sense.
How do you have the amp hooked up?
Is the amp remote powered, or does it plug in right where it is used? If it is remote powered, putting in outside where the cable comes to the house will help.

[bogyver]

Some times an amp can amplify noise on your line that it deceases the signal strength or can increase your signal so much that it floods the rf receiver and it thinks it weaker signal. I would recommend placing the amp as close to the source as possible.

[Anthony]

I'm trying to set up GBPVR with a Hauppauge HVR-1600 to receive and record QAM digital channels. When I scan the channels, I don't find/get all the QAM channels that my new HDTV can find. The HDTV has a signal strength meter and the channels not found by GBPVR are the weaker channels. The TV says the signal strength is near 10 for some channels (scale of 10) and near 3 for others when I bring the cable straight to the TV.

TV tuners are generally better quality that what is in the HVR-1600. At least that's my experience.

Have you tried the Hauppauge digital signal strength meter to see what kind of SNR you are getting on the HVR-1600?

I tried 6 different amplifier models! They ranged in price from $25 to $130 and in style from single output to 8 outputs. Every single one produced a DECREASE in signal strength

Amplifiers will increase the noise along with the signal. Unless you have to split the cable signal into several different outlets, you probably have enough signal strength now since you're on cable. I'm betting the problem is probably due to noise in your in-house cable wiring.

Surely there is some way to get a strong signal from the point where the cable enters the house to other points in the house.

I recommend at least RG6 cable with good quality compression connectors on the end. The old RG59 was OK for analog TV, but it doesn't work real well for the newer digital stuff. Also, the cheap crimp on connectors can introduce a lot of noise and signal leakage compared to good quality compression connectors.

I already had RG6 in my house, but recently spent about $100 on a compression tool, high quality splitters, and new compression connectors to upgrade my house wiring.

I need to split the cable for other devices

Use good quality splitters like those made by Channel Master, not the cheap ones you pick up at RadioShack or a home center.

Before you start splitting the signal, run a direct line from the incoming cable directly to your HVR-1600 tuner. If you still get weak signals, you may want to contact your cable company and have them come check things out. You're paying to have a strong clear signal delivered to your house. But once you start splitting the signal, you're on your own.

I use a 2-way splitter to run one line to my computer, and the other line to our TV's. The line that comes to my computer is then split three ways to my cable modem, and two HVR-1600 analog tuners (I use an antenna with the digital tuners). The TV line is split three ways also, running to our living room and bedrooms. I don't use any amplifiers.

Even with good quality wiring, and having the cable company check my signal strength and quality twice, I could never get my HVR-1600 digital tuners to lock on to the QAM stations reliably. They looked fine for viewing, but were always jumbled when recorded. After battling with that for months, I switched to an outdoor antenna for my local digital stations, and only pick up a few analog stations from my cable company. Things have worked much better since then.

Good luck,

Anthony

[ilovejedd]

I've had very good experience with Regal and Channel Vision splitters.

Tried Perfect Vision 4-way splitters (bought from Cyberestore along with an HDHomeRun) but I was getting really low signal strength and SNR (and pixelation on both cable box and HDHomeRun). I was planning on buying an amp and while I was doing my research, I read that a change of splitters might be worth a try. Bought a couple of Regal 4-way splitters for $2 a piece and what do you know, that did the trick.

[dennit]

That doesn't make sense.
How do you have the amp hooked up?
Is the amp remote powered, or does it plug in right where it is used? If it is remote powered, putting in outside where the cable comes to the house will help.

I'm not sure what didn't make sense, so if it's still unclear after I respond, ask again. I've jsut spent the last day and a half trying to make progress, but still no luck. I'm ready to tear my hair out. (sorry, frustration is bit9ing hard right now.)

OK, answers: The amp plugs in where it is used. I'm going to answer some more questions with responses to others.

[dennit]

Some times an amp can amplify noise on your line that it deceases the signal strength or can increase your signal so much that it floods the rf receiver and it thinks it weaker signal. I would recommend placing the amp as close to the source as possible.

I've done multiple tests, So I'll post some here. I'm checking "signal strength" on my new Samsung 52A650 and also on the WinTV HVR1600 Digital Signal Quality meter app that shows SNR (Signal to Noise Ratio).

The The signal is strongest on low frequency channels and gradually gets worse on higher frequency. The highest frequency I'm interested in is cable channel 88-3 which is in the 600 MHz range as far as I can tell. The amp, and all amps tested are marked at least 900 MHz.

The signal strength direct from the wall to TV with no amp on the worst channel is 5-6 on the TV strength meter and 29.7 SNR on WinTV. Putting a splitter in drops it to 4 on the TV and 28 SNR. Taking the splitter out and putting in the amp at the house entrance between the wall and TV drops it to 1at the TV!

[Anthony]

The signal is strongest on low frequency channels and gradually gets worse on higher frequency.

That seems to confirm a cabling and/or connector issue. Higher frequencies are a lot more sensitive to the cable quality than low frequencies.

29.7 SNR on WinTV.

That would be a good SNR for over-the-air, but if I remember correctly QAM cable needs to be in the 30's to get a reliable lock.

The signal strength direct from the wall to TV

Unless the incoming cable runs directly to the wall outlet, you'll still be going through the cable wiring in the house. If the cable company terminates their line on the exterior of your house, try running a direct RG6 cable from that point to the HVR-1600 tuner (even out through a window would work for testing). If your signal quality is better, you'll know you need to update the house wiring. If the signal quality is the same, there's no more you can do on your end and will need to contact the cable company.

putting in the amp at the house entrance between the wall and TV drops it to 1at the TV!

Forget the amp for now. It's obviously hurting your signal more than it's helping. I had the same problems with an amplifier, and found improving the cable connections had a greater effect on signal quality than adding an amp.

29.7 SNR on WinTV. Putting a splitter in drops it to 4 on the TV and 28 SNR.

That sounds about right for splitter losses.

Take care,

Anthony