Coax Cable Tester -- Need Suggestions

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PTNL

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I'm looking to purchase a coax cable tester. I'm looking for something beyond a continuity tester, as I'd really want to attach it to a "live" coax cable line and see how much power is coming through. This would primarily be used in my own home, and to randomly check the power coming from Charter Communications for my internet connection, though I may actually get cable TV and some HD programming as well (if that makes a difference on any suggestions given).

Anyone have any experience or suggestions on what to buy? Links to the product are preferred.


Side-thought...
Also, if anyone has any good links on what ranges/readings are acceptable for internet and stuff on coax data transmission in general, then please pass them along. I'm in no rush, and will be doing some reading over the next weekend to get more familiar.
 
what you're looking for is a coax signal meter pretty much. Those things can check signal leakage, ingress (noise going into your line), signal strength, etc. Range in price from a hundred bucks to thousands. A lot of cable companies use ones made from sadelco I think. Just google coax signal meter. pretty much just plug the coax into the meter and set it to a certain channel, it'll then give you a reading. You would change the channel on the meter to get readings for basic tv service, on demand, high speed internet and what not.


So are you having problems with your service or something? meters are pretty pointless if its just for your own personal use imho. You can just as easily check your signal strength via your modem or cable box.
 
Thanks for the details on the meter. I wasn't sure of a price range for the device, so that does sound a bit excessive.

How would I check the signal strength from my cable modem? I have a Motorola SB5101U cable modem, and haven't seen any documentation or links on Motorola's site on how to do this.
 
It's been a while but I think the default address for your surfboard would be192.168.100.1 just type that address into your browser and it'll take you to your modems status page. from there you can see your modems upstream, downstream and signal to noise ratio. those 3 readings alone will pretty much tell you if your connection is running correctly.

for the readings:

signal to noise ratio(SNR): 30db or higher
downstream: between -15 and 15, that's pretty much the extreme for your modem to block sync, you want it at -10 to 10 range.
upstream: 55db or lower.

if the readings on the modem are out of that range then something is wrong.
 
Thanks for the IP. When I plug the main house line into the cable modem, this is what is reported from Motorola's interface:

Downstream
Frequency = 591000000 Hz
Signal to Noise Ratio: 39.5 dB
Power Level: 3.5 dBmV

Upstream
Channel ID = 1
Frequency = 23160000 Hz
Power: 58.2 dBmV


Normally I have the main line split using a 4-way splitter (Ideal brand, 5MHz-2.3Ghz splitter) that has a line labeled "power pass" going to the cable modem. This setup had been working fine for over a year. It's only recently that I've been experiencing some issues that had me questioning the signal strength coming into my home. And that only happens when I plug the main line into the splitter; connecting the cable modem directly to the main line works fine, and it seems to even initialize faster this way.

So my first question is whether or not the values reported are cause for calling Charter to come out and examine the lines and the box outside my house.
 
The signal from Charter is probably going to be fine. Your upstream power level is too high. This can be resolved by reducing the number of splitters. Use a two way splitter from the main line. It needs to be a -3.5 dB splitter. Run one of the splits directly to the cable modem. Run the other side out to your televisions, splitting that side as necessary. You do not want to put the cable modem behind multiple splits, or it will cause your power levels to go out of range.

As a test, plug the main cable line into the modem without any splitters at all. See what your power levels are then.
 
ewb302 said:
The signal from Charter is probably going to be fine. Your upstream power level is too high. This can be resolved by reducing the number of splitters. Use a two way splitter from the main line. It needs to be a -3.5 dB splitter. Run one of the splits directly to the cable modem. Run the other side out to your televisions, splitting that side as necessary. You do not want to put the cable modem behind multiple splits, or it will cause your power levels to go out of range.

As a test, plug the main cable line into the modem without any splitters at all. See what your power levels are then.
Click to expand...
The numbers reported were actually when the main line was plugged directly into the cable modem -- the cable modem no longer fully initializes when going through the current splitter.

Agreed on the multiple splits part. I had thought the "power pass through" connection on the splitter was beneficial for the cable modem. I'll go with the two separate splitter arrangement you suggested.



Grentz said:
Get a good high frequency 2 way splitter and run one branch to your modem and one to your other splitter for TVs and such.

Something like one of these:
http://www.solidsignal.com/pview.as...e-signals-(SKY23302D)&c=Signal Splitters&sku=

Or these:
http://www.solidsignal.com/pview.as...r-52300-Mhz-(PV23302)&c=Signal Splitters&sku=

would be very good. They use printed circuit boards inside and generally perform very well.
Click to expand...
Thanks for the specific part suggestions. I'll order one of them later this week.

Got a suggestion on a 3- or 4-way splitter to connect the household television lines to?
 
You can go all out and get the same style in a 4 way:
http://www.solidsignal.com/pview.as...-(SKY23304D)&c=Signal Splitters&sku=SKY23304D

or 3 Way:
http://www.solidsignal.com/pview.as...Mhz-(PV23303)&c=Signal Splitters&sku=PV23-303

(BTW, I really like Skywalker and use them myself...though with satellite. Those Perfect Vision ones are pretty much the same thing as well)

Eagle Aspens are good as well if you want to save a bit of money on the 3 way/4 way.

Good 3 way Eagle Aspen:
http://www.solidsignal.com/pview.as...P7003AP)&c=Signal Splitters&sku=mc8s026005573

4 way:
http://www.solidsignal.com/pview.as...P7004AP)&c=Signal Splitters&sku=mb8s02405544r
 
Thanks for all the great links and advice, everyone. I just placed an order for the 2- and 4-way Skywalker splitters. I'll post some updated numbers from my cable modem when the new parts arrive and are dropped into placed.
 
Sounds good, the skywalkers are some of the best you can buy TBH. Never had any trouble with them.
 
Just got the Skywalker parts installed in the way specified: main line --> 2way splitter for cable modem and another to 4-way for televisions. Motorola cable modem initialized fine, and online speed tests still show at least what I'm paying for in speed. TV signal looks alright. So far so good...


Here's the new numbers reported by cable modem about the signal strength:

Downstream
Frequency = 591000000 Hz (no change)
Signal to Noise Ratio = 39.4 dB (0.1 db drop)
Power Level = 1.2 dBmV (2.3 dBmV drop)

Upstream
Channel ID = 1 (no change)
Frequency = 23160000 Hz (no change)
Power = 54.0 dBmV (4.2 dBmV drop)


While I haven't noticed anything yet, do you think these new numbers are acceptable or should I be concerned?
 
Well, I just started experiencing the same problems as earlier -- Cable modem will not initialize when plugged into the two way splitter. Even when the other line is disconnected, the cable modem still will not initialize when going through the 2-way splitter.

Any thoughts on this? Do the previously listed numbers help?
 
Your upstream power level is still too high. A call to your cable company is probably in order.
 
ewb302 said:
Your upstream power level is still too high. A call to your cable company is probably in order.
Click to expand...
Will do.


Thanks to everyone for the thoughtful suggestions and advice throughout this post!!
 
I should have said "very borderline". Your upstream power level is technically in range, but even a change in temperature can cause it to fluctuate out of range. You really want to get that upstream power level down in the 40's if possible. It might be a problem up the street that only your cable company can correct...
 
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