Cable TV Distribution Amplifier Recommendations.
- Thread starter George7941
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How much longer is there going to be analog cable, anyway? I'd band-aid this and get ready to abandon the 59 in the wall.
When (not if) you get digital cable the little box is going to need two-way communication, which the amps can interfere with. Unless you're lucky and get ClearQAM or whatever the TV can natively decode.
When (not if) you get digital cable the little box is going to need two-way communication, which the amps can interfere with. Unless you're lucky and get ClearQAM or whatever the TV can natively decode.
Originally Posted By: ROLEXrifleman
From one of our old installer manuals
dBmV = decible millivolt = an exponentially-weighted measure of the signal's power.
Not to be confused with Dbi and Dbd which can be manipulated to make a wet noodle look good.
From one of our old installer manuals
dBmV = decible millivolt = an exponentially-weighted measure of the signal's power.
Not to be confused with Dbi and Dbd which can be manipulated to make a wet noodle look good.
My friend already has digital cable, I think. The existing fifteen year old amplifier is not causing any issues with digital cable. I know very little about cable tv's, I don't even have a tv in my house.
Here is my signal strength meter
Before I call the cable company complaining about the drop, I would like to verify the accuracy of my meter. Would an oscilloscope be able to measure the signal strength, say by measuring the waveform amplitude?
I already have a spool of RG6 cable. Is it worth spending the extra money to acquire quad shield cable?
https://www.homedepot.ca/en/home/p.100-feet--blk-rg6-quad-shielded-coax-cable.1000724869.html
Here is my signal strength meter
Before I call the cable company complaining about the drop, I would like to verify the accuracy of my meter. Would an oscilloscope be able to measure the signal strength, say by measuring the waveform amplitude?
I already have a spool of RG6 cable. Is it worth spending the extra money to acquire quad shield cable?
https://www.homedepot.ca/en/home/p.100-feet--blk-rg6-quad-shielded-coax-cable.1000724869.html
If it is good cable, no. Cheap cable can have poor braid coverage that will let rf in / out that a better cable won't. That may or may not make any difference in your location.
I met one of the local cable techs last week, standing in front of my house, looking up at my roof tower. He was looking for a leak, and said most of their problems with signal strength, ingress / egress, are from bad connectors.
I met one of the local cable techs last week, standing in front of my house, looking up at my roof tower. He was looking for a leak, and said most of their problems with signal strength, ingress / egress, are from bad connectors.
You're wiring set up is bass akwards. Meaning the splitter is before the amp. Should be the other way around. Then feed the 100' run straight from the amp, since you reported only one set with a poor picture.
Try rearranging before removing the RG59. It may work.
Don't need to buy 6QS if you already have a spool of 6.
Try rearranging before removing the RG59. It may work.
Don't need to buy 6QS if you already have a spool of 6.
Originally Posted By: George7941
...... Would an oscilloscope be able to measure the signal strength, say by measuring the waveform amplitude?
It would have to have extreme bandwidth, so, no. A spectrum analyzer is what you need for that task.
edit: If you have a fixed frequency, signal source, and your scope has the bandwidth to display that frequency signal, then, yes, you could use it to measure the loss in your cable at that frequency, and determine if the cable is still in spec, bad connector, or other issues. Not sure if that is what you meant.
...... Would an oscilloscope be able to measure the signal strength, say by measuring the waveform amplitude?
It would have to have extreme bandwidth, so, no. A spectrum analyzer is what you need for that task.
edit: If you have a fixed frequency, signal source, and your scope has the bandwidth to display that frequency signal, then, yes, you could use it to measure the loss in your cable at that frequency, and determine if the cable is still in spec, bad connector, or other issues. Not sure if that is what you meant.
Last edited:
Originally Posted By: sleddriver
You're wiring set up is bass akwards. Meaning the splitter is before the amp. Should be the other way around. Then feed the 100' run straight from the amp, since you reported only one set with a poor picture.
Try rearranging before removing the RG59. It may work.
Don't need to buy 6QS if you already have a spool of 6.
That was my reaction when I saw the splitter before the amp. But that is the way the tech from the cable company installed it.
You're wiring set up is bass akwards. Meaning the splitter is before the amp. Should be the other way around. Then feed the 100' run straight from the amp, since you reported only one set with a poor picture.
Try rearranging before removing the RG59. It may work.
Don't need to buy 6QS if you already have a spool of 6.
That was my reaction when I saw the splitter before the amp. But that is the way the tech from the cable company installed it.
Originally Posted By: Win
It would have to have extreme bandwidth, so, no. A spectrum analyzer is what you need for that task.
edit: If you have a fixed frequency, signal source, and your scope has the bandwidth to display that frequency signal, then, yes, you could use it to measure the loss in your cable at that frequency, and determine if the cable is still in spec, bad connector, or other issues. Not sure if that is what you meant.
I don't have a signal generator appropriate for tv signal work. My question was in relation to hooking up the scope to the incoming cable and measuring the strength of the signal coming in from the street. If I could prove that the incoming signal was weak then I could ask the cable company to fix it.
The most powerful scope I have is a Rigol DS1052E, with a rated bandwidth of 50 MHz
https://www.rigolna.com/products/digital-oscilloscopes/ds1000e/ds1052e/
It would have to have extreme bandwidth, so, no. A spectrum analyzer is what you need for that task.
edit: If you have a fixed frequency, signal source, and your scope has the bandwidth to display that frequency signal, then, yes, you could use it to measure the loss in your cable at that frequency, and determine if the cable is still in spec, bad connector, or other issues. Not sure if that is what you meant.
I don't have a signal generator appropriate for tv signal work. My question was in relation to hooking up the scope to the incoming cable and measuring the strength of the signal coming in from the street. If I could prove that the incoming signal was weak then I could ask the cable company to fix it.
The most powerful scope I have is a Rigol DS1052E, with a rated bandwidth of 50 MHz
https://www.rigolna.com/products/digital-oscilloscopes/ds1000e/ds1052e/
If your friend has digital cable, I believe they should be able to pull up the signal strength when the tv is on. I'm not sure how to pull up this menu since i don't know who their cable company is. Here's a random image from google showing what I mean.
http://www.avsforum.com/forum/attachment.php?attachmentid=467274&d=1420761765
http://www.avsforum.com/forum/attachment.php?attachmentid=467274&d=1420761765
Originally Posted By: George7941
Originally Posted By: sleddriver
You're wiring set up is bass akwards. Meaning the splitter is before the amp. Should be the other way around. Then feed the 100' run straight from the amp, since you reported only one set with a poor picture.
Try rearranging before removing the RG59. It may work.
Don't need to buy 6QS if you already have a spool of 6.
That was my reaction when I saw the splitter before the amp. But that is the way the tech from the cable company installed it.
Your intuition is correct. He installed it backwards. Doing so just increases the noise floor. Swap it and see what happens.
Originally Posted By: sleddriver
You're wiring set up is bass akwards. Meaning the splitter is before the amp. Should be the other way around. Then feed the 100' run straight from the amp, since you reported only one set with a poor picture.
Try rearranging before removing the RG59. It may work.
Don't need to buy 6QS if you already have a spool of 6.
That was my reaction when I saw the splitter before the amp. But that is the way the tech from the cable company installed it.
Your intuition is correct. He installed it backwards. Doing so just increases the noise floor. Swap it and see what happens.
I wonder if the splitter is before the drop amp, so that the signal to the cable modem (if there is one) doesn't go through the drop amp. I don't think a 15 year old amp would have a passive port for cable modems like the newer ones do.
Re displaying signal strength on the tv, the example posted shows "downstream rcvd power = 12.3 dbmv" and "upstream power = 48.5 dbmv". Which of the two powers should I be looking at?
Now that I have some sleep under my belt........
If the splitter/amp configuration is all in the same place,
Disconnect the MAIN input feeding the the three way you mentioned. Unscrew the leg that feeds the TV with the issue. Use a barrel and connect the two together. you now have a "straight" shot from the pole. If the tv reception clears up you know you have a configuration issue and should attempt to put the Amp at the beginning of the system so it feeds the three way, not the three way feeding it.
If you still have a bad picture you know there is an issue with that 100ft run, replace it. you did mention there is a 20ft section you cant see....... a lot can happen in 20 ft
If the splitter/amp configuration is all in the same place,
Disconnect the MAIN input feeding the the three way you mentioned. Unscrew the leg that feeds the TV with the issue. Use a barrel and connect the two together. you now have a "straight" shot from the pole. If the tv reception clears up you know you have a configuration issue and should attempt to put the Amp at the beginning of the system so it feeds the three way, not the three way feeding it.
If you still have a bad picture you know there is an issue with that 100ft run, replace it. you did mention there is a 20ft section you cant see....... a lot can happen in 20 ft
Originally Posted By: sxg6
I wonder if the splitter is before the drop amp, so that the signal to the cable modem (if there is one) doesn't go through the drop amp. I don't think a 15 year old amp would have a passive port for cable modems like the newer ones do.
You nailed it. I checked and one of the outputs from the splitter, before the amp, feeds the cable modem.
I wonder if the splitter is before the drop amp, so that the signal to the cable modem (if there is one) doesn't go through the drop amp. I don't think a 15 year old amp would have a passive port for cable modems like the newer ones do.
You nailed it. I checked and one of the outputs from the splitter, before the amp, feeds the cable modem.
Upstream and downstream power are both important, but downstream is the value to look at. I'd also be curious to know what the downstream SNR (signal to noise ratio) is.
*One more quick thing. Does it cost money to have a tech come by and take a look at things? I know with comcast/xfinity, they'll give you a brand new drop amp, splitters, put new fittings on the cables, almost anything they can do ensure things get fixed for you. They can also check the signal coming into the house, and at the tap (or whatever it's called) outside the house, to see if the cable going to the house is bad, like suggested earlier.
*One more quick thing. Does it cost money to have a tech come by and take a look at things? I know with comcast/xfinity, they'll give you a brand new drop amp, splitters, put new fittings on the cables, almost anything they can do ensure things get fixed for you. They can also check the signal coming into the house, and at the tap (or whatever it's called) outside the house, to see if the cable going to the house is bad, like suggested earlier.
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