Video Amplifiers

[garyellis]

OK..I don't know anything about Amplifiers...

My PVR 150 card is working fine, but picture could be some better...MY 500 card has a real grainy picture, so I sent it to Hauppauge to get a new one..assuming it comes back and is still producing grainy video, it may be my cable signal strength.

Thus, I need some help understanding amplifiers...any body have knowledge or suggestions?

I looked on line and saw some that look just like splitters...is that the way to go?

Any HELP appreciated...

Gary Ellis

[deria]

This is my personal experience only. There are basically 3 options:

There are powered video amplifiers, typically availalbe from radio shack, which will allow you to split your signal multiple times without losing signal quality. My experience with these has been that they introduce noise into the signal and are hard to adjust (ie: you need to use a screwdriver to modify the amount of gain). I used one to split my cable into a 4-way split.

There are also standard cable splitters, which are not powered. The more splits you have, the more signal you lose. They don't introduce noise, but they also don't compensate for signal loss due to the splitting.

The third option is whats called a high performance cable splitter. I've just started seeing these around at Radio Shack, and they are like a standard cable splitter in that they don't have any power but unlike a standard splitter they seem to lose very little signal. I installed an 8-way splitter and all 8 of the splits have a crystal clear picture. The device is a 5-2300Mhz high performance 8-way splitter, with all ports offering power pass (for bidirectional communication and such). I'm very happy with it.

If you are not splitting your signal and its still weak... call your cable company. Quite oftent eh wires that carry the signal outside your home or apartment are quite old and in need of replacement.

[garyellis]

Thanks, very good information...

I am splitting my cable from the street 4 ways currently....and then one of those splits again 4 ways..and another splits 2 ways.

So, I have a lot of splits...If I can get my 500 and my 150 cards all working with good video, then I can reduce the number of splits, because I will use MVP instead of cable at 3 of the tv's. Plus, if I can use another 500 card, then I can take out more splits.

the no loss - non power splitter that you described sounds like its worth a try. I'm heading over to a radio shack just down the road and see what they have.

Thanks...

Gary Ellis

[thatdude90210]

It's best to use the same professional quality amps that cable companies use, that's Electroline. They come in various number of splits and configs. They are fairly cheap on ebay.

[stanger89]

First things first, I would recommend eliminating all (or at least as many as possible) splitters between your cable feed and your PVR500. If that cleans it up, then you've got a signal strength issue.

If that's the case, then you can look to increasing your signal strength at the 500. That can be achieved several ways:

1. Reduce the number of splits, and/or, "balance" them. Each 2-way split will drop the signal power by half, actually a bit more (usually 3.5-4dB). A 4-way splitter will usually drop it 6-7dB (about 1/4th). The fewer splitters the signal goes through the better, one 4-way is better than a bunch of daisy-chained 2-ways (at the end of the daisy chain you're looking at about a 10dB drop vs 6dB with a 4-way)
2. Add an amplifier, that could be an inline amp, or a distribution amp/splitter. The important thing to remember with an amp is that you want to feed it the best signal possible, because it amplifies signal and noise, basically it doesn't help your signal-to-noise-ratio (SNR). Sticking an amp right before your tuner won't do much good because you're just amplifying noise (low SNR). If you stick it back before your cable runs and splitters, you'll have the best SNR possible, and will retain the highest SNR possible.

[hemicuda]

I'll have to see if our local store is still open. A big portion of the RS's in the southeast are closing this week according to the grapevine. I plan on a 4-way to give each room a drop and a 2-way in front of that for the cablemodem to give it the best signal I can. 1 of the 4-way drops will get split for STB and 2 PVR cards. Maybe I'll have enough signal to them so I don't have to split out the modem line.

[paulbeers]

I have an RS 4 way video amplifier. I'm not all that impressed with it, however, it does allow me to split 4 ways without any noticable image loss. I have my server right next to the amplifier and I have one of the posts of the amplier feeding my sage server. Before I switched my PVR500 from cable to now only doing OTA SD (since my local channels come in like crap thru my cable connection), I would use a 3 way splitter off one of the amp's posts. This splitter had a 4 db loss on one of the posts and 7 db loss on the other two. My 2 PVR150's would get the 7 db loss posts and the PVR500 got only the 4 db loss. This was the only way I could get a decent signal from the pvr500. If I had to do it all over again, I would have bought the nvidia card. Dang.

[stevech]

Amps with a low noise figure (additive noise) cost a lot more. Lower the noise figure spec, the higher the price.
Try to buy amps that actually spec this and compare.

[malbec]

My two cents ... make sure you have high quality wheather proof cable ends on your cable lines as well (Home Depot seems to be the source for finding do-it-your-self kits for these. Otherwise, you can find them online at places like this http://www.partsexpress.com/pe/showd...number=092-402). I have seen 1-3db of signal strength loss from poor ends quite often.

[thatdude90210]

Yep, good connectors are a good idea. I replaced all of mine with Digicon connectors, again that's what cable co's use. With a compression tool, coax stripper, and bag of connectors all off of ebay, I redid all my old crappy connectors.

[garyellis]

Lots of good stuff here...

Now given that the signal has a strength or lack of strength, it must be measureable. I should be able to find a tool to connect to cable coming in from the street and measure the strength, and then go to the cable after a split and measure and so forth...

Then I could find what needs to be replaced or amplified...

So, how do I measure signal strength? I'm sure there must be some device..

Thanks,

Gary

[stanger89]

There most definitely are tools for measuring signal level, though I think their somewhat impractical for the home user, eg:
http://www.markertek.com/SearchProdu...ff=0&sort=prod

The best way, as a home user, is simply to remove as many splitters as possible (all if possible), and see if the direct signal is improved over the split one. If not, I'd call the cable company and complain, or try an amp.

[src666]

What you need is a video distribution amplifier - ChannelPlus is the brand I usually recommend. They come in a variety of sizes.

A couple of tips:

1 - Amplify as close to the curb as possible. You want to position your amp as close to the signal source as you possibly can. If you have Digital Cable or a Cable modem, use a bidirectional amp.

2 - Split as cose to the signal consumer as possible. You want your splitter to be the very last thing on the cable before the TV/capture board. This only applies to unamplified splitters. Avoid them if you can, if not, put them last.

3 - Split once. Find an amp/splitter that handles all of the outputs that you need. If you can't do that, then just put a splitter before the amps and use 2 amps. Using a cascading chain of splitters throughout the house is a fast ticket to lousy signal. Obey rule 1.

4 - Cap off any unused ports. 75 Ohm RF termination resistors are cheap and easy to find (Radio Shack, online, etc.). They will prevent unwanted signals from being introduced due to an unterminated connection. This applies both at the splitter/amp and at the wall - those wires are big antennas.

5 - Don't cheap out. This should be a one-time expense, so make it a good purchase.

[garyellis]

Thanks for the POST..

Yesterday, I removed all splitters and got a good 1 to 4 bidirectional splitter (non amplified). I ran 1 line for internet, 1 to my cableset top box and 1 to my PVR 150. The 4th will go to my PVR 500 when it gets returned from Hauppauge. I have been complaining about the picture quality through the PVR 150 for 3 months. It is now outstanding. The picture is as good as through my cable settop box. So, I am anxious to get my PVR 500. Hopefully the signal will be strong enough to drive both tuners. If not, then I will go the amplifier route.

Thanks for the help....Next task is trying to figure out how to get my Sony XBR to play component input (non HD) in 4X3 format...It curently plays any input through component as a 16X9, even though my tv is a4X3...So, I use S-video for SageTV.

Gary