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Discussion Starter · #1 ·
Hi,
I have been using my Series 3 for about 3 weeks now, and for the most part have been happy. However, I have been experiencing occasional pixelization on a handful of HD channels.

My current setup:
Cable in -> Electroline EDA-FT08100 8 port bi-di powered splitter -> Series 3 TiVo (plus Series 2 TiVo and other TV connections on other ports of the Electroline amp, but no splits before the Series 3 TiVo)

Before the Series 3 TiVo, I used a Motorola Broadband Amp to boost the incoming signal, and it worked satisfactorily with the TW/now Comcast DVR and the Series 2 TiVo split from the same cable.

Since installing the Electroline splitter, the situation has improved significantly, but I still noted some pixelization on the local NBC HD channel last night (Scrubs rerun, so I went to another station). I also at one other point last week noted pixelization on another HD channel as I was surfing.

I have not measured the signal strength since installing the Electroline splitter last week, but before the Electroline, using the Motorola amp and a single split (Series 3 TiVo and Series 2 TiVo), I had much more pixelization in general with some signal strengths down in the 78-85 range.

Any thoughts? I figure that I have optimized all that I can (other than buying Monster cables :rolleyes: ), by removing all splits and using an amplified splitter.
 

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It is just as easy to overdrive the signal into pixelation issues as to have a weak signal. You need to measure the input on the channels having trouble and determine the course of action.
 

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Discussion Starter · #4 ·
Tim N. said:
It is just as easy to overdrive the signal into pixelation issues as to have a weak signal. You need to measure the input on the channels having trouble and determine the course of action.
Will an overdriven signal to the TiVo manifest itself as signal strength 100 at the TiVo? Or do you recommend some other way to check for signal strength?

Before the amplified splitter, I had a couple of channels in the low 90's coming in fine (as well as a couple of pixelated channels at 78-85). I am expecting to see essentially all channels in the 90's now.

Thanks.
 

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If you get a quality amp/signal cleaner, you won't over-amp anything.

I've used Viewsonics brand for OTA ATSC, crappy Comcast, and now FIOS TV. It's cleaned up pixellation on all of them, without screwing anything up by over-amping. They seem to be smart enough to amp the weak stuff without amping the already strong stuff.
 

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Discussion Starter · #6 ·
litkaj said:
Try the following:
  • Replace any RG-59 with Quad-shielded RG6.
  • Use the smallest splitter you can get away with (no unused ports)
  • Cap off any wall jacks that aren't in use
1) I will look at replacing the cable to the Series 3 TiVo with the quad-shielded RG-6 (from the splitter all of the way).
2) I actually have 10 jacks in the house, only three of which are actively in use currently. I purchased the Electroline spliiter/amp for the capacity (and the specs - looked to be the best).
3) I can cap off wall jacks not in use - exactly what will capping the jacks do to improve performance (eliminate signal reflection/interference?)?

Thanks
 

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Discussion Starter · #7 ·
AbMagFab said:
If you get a quality amp/signal cleaner, you won't over-amp anything.

I've used Viewsonics brand for OTA ATSC, crappy Comcast, and now FIOS TV. It's cleaned up pixellation on all of them, without screwing anything up by over-amping. They seem to be smart enough to amp the weak stuff without amping the already strong stuff.
Hi,
Can you forward the model number you use (I want to check the specs)?

Thanks.
 

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lethcoeb said:
Will an overdriven signal to the TiVo manifest itself as signal strength 100 at the TiVo? Or do you recommend some other way to check for signal strength?

Before the amplified splitter, I had a couple of channels in the low 90's coming in fine (as well as a couple of pixelated channels at 78-85). I am expecting to see essentially all channels in the 90's now.

Thanks.
Hopefully you can measure the signal before and after amplification. If you see over 90 before amplification, then don't use the amp. If just one or two channels have low signal and the amp gets them to 70+, then you need to decide if it is better to help the weak when you might be damaging the stronger stations.
 

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Re: cable. You really only need to use quad shield if there is strong R.F. interference. Any good quality RG-6 will work fine and is easier to route and terminate.

Re: capping outlets. A good idea but be sure that, if you are using an amplified splitter, that it is OK to do so. The one I am using, an 8 port ChannelPlus, specifically states not to cap unused ports as it will short out the power supply.
 

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lethcoeb said:
1) I will look at replacing the cable to the Series 3 TiVo with the quad-shielded RG-6 (from the splitter all of the way).
2) I actually have 10 jacks in the house, only three of which are actively in use currently. I purchased the Electroline spliiter/amp for the capacity (and the specs - looked to be the best).
3) I can cap off wall jacks not in use - exactly what will capping the jacks do to improve performance (eliminate signal reflection/interference?)?

Thanks
If you only use 3 jacks, you should use a splitter and/or amplifier with no more than 3 outputs. I only have two outputs and a non-powered splitter works great.

As for Coax cables, I made several changes including quad shielding before upgrading to CinemaQuest (by AudioQuest) cable available at Magnolia Audio Video. I made the upgrade to CinemaQuest when I still had an analog TiVo, and the CinemaQuest got rid of all ghosts and artifacts. The other 3 or 4 quad shielded cables I tried did not do anywhere near as good of job. I have seen no reason to make any changes since getting an S3, as my picture is clear and I have only neglible pixalation (e.g., I saw no pixalation in any of the 6 HD Star Wars movies I recently recorded).

As for cables in general, I use a combination of Monoprice and AudioQuest/CinemaQuest for my cable needs. Monoprice is great for most digital lines, and AudioQuest/CinemaQuest fills in the gaps - for speakers, subwoofer RCA, and Coax. Monster cable is a total ripoff. It is way over priced.
 

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Discussion Starter · #11 ·
Tim N. said:
Hopefully you can measure the signal before and after amplification. If you see over 90 before amplification, then don't use the amp. If just one or two channels have low signal and the amp gets them to 70+, then you need to decide if it is better to help the weak when you might be damaging the stronger stations.
Before using the powered splitter (with one two-way splitter in the system), I would have signals from the high 70's to the low 90's amongst my HD channels.

My goal is to watch ALL channels without pixelization. I would hope that the S3 could handle the incoming signal the same that the CableCo's DVR could (or at least work better with some amplification).

The Electroline splitter I use should not be overdriving - it splits without signal degradation (i.e. each port is +0db, instead of -3.5db for 2-way splitters or -7db for 4-way splitters).

The Motorola (currently removed from the system) does amplify the signal (I think +3db) and was great when I had multiple splits before I owned the S3.

Again, how does an overdriven signal manifest itself at the TiVo (signal strength of 100?)?

drew00001 said:
If you only use 3 jacks, you should use a splitter and/or amplifier with no more than 3 outputs.
Although I am currently using only 3, I do not want to limit myself for the future and want to be able to drive all 10 jacks with cable signal (even if I need to have a splitter or two). I figure that with a powered splitter with +0db passthrough, I am no worse than plugging directly into the cable from the street.

Thanks for the help so far - I'm hoping that whatever consensus is arrived at here can help others in my situation in the future.
 

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lethcoeb said:
Before using the powered splitter (with one two-way splitter in the system), I would have signals from the high 70's to the low 90's amongst my HD channels.

My goal is to watch ALL channels without pixelization. I would hope that the S3 could handle the incoming signal the same that the CableCo's DVR could (or at least work better with some amplification).

The Electroline splitter I use should not be overdriving - it splits without signal degradation (i.e. each port is +0db, instead of -3.5db for 2-way splitters or -7db for 4-way splitters).

The Motorola (currently removed from the system) does amplify the signal (I think +3db) and was great when I had multiple splits before I owned the S3.

Again, how does an overdriven signal manifest itself at the TiVo (signal strength of 100?)?

Although I am currently using only 3, I do not want to limit myself for the future and want to be able to drive all 10 jacks with cable signal (even if I need to have a splitter or two). I figure that with a powered splitter with +0db passthrough, I am no worse than plugging directly into the cable from the street.

Thanks for the help so far - I'm hoping that whatever consensus is arrived at here can help others in my situation in the future.
The Electroline is top notch stuff. It has 3db of forward gain and even provides reverse path gain to negate the loss of the splitter (which you dont really need for the S3). Does your documentation indicate what the 'noise figure' is for the amp? It should be less than 3db.

Im currently using a Viewsonics 8 port which is very similar to your Electroline (except mine doesnt have reverse path gain). Ive also used a PCT 8 port and 4 port. None of them made any impact on my pixelation issues.

I would put F-Terminators on the unused outputs to eliminate any possible signal radiation.

Who made up the cable connectors being used? Poor cable termination can cause all kinds of grief. The cableco recommends compression cable ends. Crimp and screw type can be problematic.
 

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lethcoeb said:
The Electroline splitter I use should not be overdriving - it splits without signal degradation (i.e. each port is +0db, instead of -3.5db for 2-way splitters or -7db for 4-way splitters).
The 0db figure is for the reverse path... i.e. where the cableco equipment talks back to the node. Forward gain for your amp is +3db which means your signal is twice as strong as the amp input. +3db should be just fine.

http://www.dropamp.com/shop/product_info.php?products_id=31

This also lists the noise figure as 3db which is very good.
 

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Discussion Starter · #14 ·
SCSIRAID said:
The 0db figure is for the reverse path... i.e. where the cableco equipment talks back to the node. Forward gain for your amp is +3db which means your signal is twice as strong as the amp input. +3db should be just fine.

http://www.dropamp.com/shop/product_info.php?products_id=31

This also lists the noise figure as 3db which is very good.
Oops - you're right - I did not look at the spec before posting.

I'll also look at the cable terminations, especially in line with the S3.

Getting back to Tim N.'s point, I'll check the signal strengths on the HD channels again with and without the powered splitter to see if I am overdriving those channels.

Good stuff coming across here today - thanks for the help so far...
 

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Discussion Starter · #15 ·
SCSIRAID said:
Im currently using a Viewsonics 8 port which is very similar to your Electroline (except mine doesnt have reverse path gain). Ive also used a PCT 8 port and 4 port. None of them made any impact on my pixelation issues.
I see from other threads that you are having pixelization issues with the 8.3 software - is it across all channels, or specific to certain ones?

I'm inclined to think it is not an 8.3 issue with my setup, since all but a handful of my channels are not pixelated, and those which are previously had lower signal strengths. I want to optimize my signal strength, etc. before beating up on TiVo.
 

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lethcoeb said:
Will an overdriven signal to the TiVo manifest itself as signal strength 100 at the TiVo? Or do you recommend some other way to check for signal strength?

Before the amplified splitter, I had a couple of channels in the low 90's coming in fine (as well as a couple of pixelated channels at 78-85). I am expecting to see essentially all channels in the 90's now.

Thanks.
Are you measuring with a coax signal strength meter or using the Tivo's indicator. I ask because the "signal strength" meter in the Tivo is not a measure of signal strength but of error rate. You could have a very weak signal which drops out from time to time and it still might display 95-100 when it is coming in (0 when it isn't).
 

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lethcoeb said:
I see from other threads that you are having pixelization issues with the 8.3 software - is it across all channels, or specific to certain ones?

I'm inclined to think it is not an 8.3 issue with my setup, since all but a handful of my channels are not pixelated, and those which are previously had lower signal strengths. I want to optimize my signal strength, etc. before beating up on TiVo.
My pixelation issues have been since day one with 8.1. 8.3 had zero effect on my situation. My issues are only on encrypted QAM channels. It pretty much occurs on ALL encrypted QAM channels.
 

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TostitoBandito said:
Are you measuring with a coax signal strength meter or using the Tivo's indicator. I ask because the "signal strength" meter in the Tivo is not a measure of signal strength but of error rate. You could have a very weak signal which drops out from time to time and it still might display 95-100 when it is coming in (0 when it isn't).
Correct (except i believe its Signal/Noise Ratio and not 'error rate'). The cableco will come out and check signal level, tilt, snr and dc offset if you ask them.

If you have one of the cableco's boxes (like a SA3250) you can enter its diag mode and it has very good signal measurements including strength and SNR and it even keeps track of Bit Error Rates.
 

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Discussion Starter · #19 ·
SCSIRAID said:
If you have one of the cableco's boxes (like a SA3250) you can enter its diag mode and it has very good signal measurements including strength and SNR and it even keeps track of Bit Error Rates.
I no longer have a CableCo box of any kind, so I'm kind of out of luck using their signal strength / SNR tools. Technically I am paying for one with my service, so I could pick one up. I'll probably get an HD one when I buy my new living room TV and retire the current plasma to the room above the garage.

I guess my last step (after following some of the above items) is to have Comcast roll a truck...
 
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