Neighbor having ISP speed problems.

2nd harmonic of the ingress test function in his tester. Some CATV testers can generate test carriers to help check for cable leakage. It can also be generated at the CMTS (cable modem termination system). Helicopters are used to fly over the cable looking for leaks. The pilot frequency is usually about 140 MHz

Another possible is the 3rd harmonic of a local FM broadcast transmitter. The harmonic need not be generated in the FM transmitter, but could simply be caused by a non-linear device in the cable system generating the harmonic. It also doesn't need to be generated in the house and could enter the cable (ingress) anywhere along the cable line. Look for loose or rotten connectors and read about ingress in CATV systems. The tech should have unplugged the house cable system from the network to see if the 300MHz signal was still there. If it goes away, it's being generated in the cable system. If it's still there, it's either in his unspecified model tester, a local radio/TV station, or being generated by something in the house. Try turning off electronics and see what happens.

Yes. The reverse (upstream) channel is usually 5-50MHz. You could be looking at harmonics from that. However, that's unlikely. Some cable modems use channels at the high end of the spectrum (>1000MHz) for upstream, but those probably won't produce 300MHz.

Ok, so you have a "leak" in the cable somewhere in the house. Tear apart the system and try to isolate the bad segment. The most likely culprits are the F connectors. Pull on the F connector. If it falls apart or disconnects from the coax, it's defective. Make sure that your cables are all RG-6/u and not RG-59/u which tends to be old and awful. Use push-on connectors (that require a push on tool to install properly), and not the ring crimp type.

Yes. The front end of the cable modem has an AGC (automagic gain control) that has signal level limits that should be observed. Too much signal will result in signal distortion. It's easy enough to build or buy a F-connector type attenuator, and add it in line at the modem. Start with 3dB or maybe 6dB. I've never had anything improve with less signal, but it's worth a try.

Thanks for reminding me about my favorite rant for this newsgroup. Is there some reason you conveniently left out most numbers that could be of use in diagnosing the problem? Is it because you've been reading Cuisitor Doom's posting and using them as a template? Perhaps you prefer vague and general answers instead of specifics? I think you get the idea. Kindly disclose:

1. Type of coax cable used in the house. If it's RG-59/u, your neighbor will not like my recommendation.
2. Model number of the cable modem.
3. Maker and model number of the tester used.
4. CATV company name.
5. DOCSIS 2.0, 3.0, or 3.1? From your stated speeds, my guess(tm) is DOCSIS 3.0

While your at it, are you doing the speed tests with a wired ethernet connection, or are you trying to do it via wireless? Wireless is often slower than your cable speed and is subject to interference from other wi-fi systems. Use a CAT5 cable (and a fast computah).

Cable modems are fairly cheap. Cable gateways, which include a router, wi-fi, switch, etc, are more expensive and difficult to find legally. This is what I like and which might work if approved by the cable ISP:

However, since he's your neighbor, you could probably remove his modem, and temporarily replace it with yours and see if it makes a difference. If nothing changes, then replacing the modem will probably not do anything useful.

Check the power supply on the modem. I've seen those deterioriate over the years and produce some really bizarre symptoms.

For signal levels, if the modem is by Arris/Motorola, point your web browser to 192.168.100.1 and you'll get some signal level diagnostics.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Sure... if one of its onboard clock/oscillator chips is running at that frequency (or a subharmonic of it like 100 or 150 MHz).

Some years ago I helped chase down an "over the air" interference problem, where a strange signal was getting into the inputs of a bunch of repeaters in the 2-meter band (144-148 MHz). We tracked down the source to an apartment building in San Jose. One apartment dweller had an Ethernet switch which was radiating a harmonic of its oscillator frequency, whenever it was passing Ethernet traffic, and this signal wandered around between 144 and 145 MHz. The signal was apparently leaking out via both the Ethernet cables and through the router's power wiring and wall-wart... strong enough to be picked up miles away!

I traded the owner one of my spare Ethernet switches for his noisy one, and the problem went away. Never did learn what was actually wrong with the noisy one (it was a well-known brand with a good reputation for quality).

It's not impossible. If a signal is too strong it can push the RF circuitry into saturation, which causes several sorts of Badness... distortion of the strong signals, suppression of weaker ones, and the creation of intermodulation "images" between strong signals.

You could try adding a 75-ohm coaxial "pad" (a bidirectional attenuator of the correct impedance) to see if it helps... try a 6 dB or 12 dB pad.

Another thing to check for, is to make sure that the home's coaxial wiring is a "straight run" from the service entrance to wherever you have the modem... no dividers or side branches. If you do have a signal splitter (so e.g. you can run both the modem and a TV or DVR) make sure that all unused ports on the splitter have 75-ohm terminators screwed into them. If there are any branches coming off of the splitter that go to other rooms, make sure they're either in use (with e.g. a TV) or have a terminator.

Unterminated branches on a coax network can cause signal reflections, and admit outside noise... both can hurt reception.

Well worth trying. Maybe see if you can get a loaner from someone to try, before spending $$.

Quite a few years ago, they drove by my house and said it was singing. It must have been pretty bad, because the, it was a mojor road near me. They replaced a bunch of connectors and said it was quiet now. Then maybe 4 years ago, two guys were outside my house asking if I had a cable running in the ground right here, nope. They suggested I needed my house rewired, but they added, if I sign up for a maintenance contract at $4 a month, they will rewire the house for free. I signed up, a month later no one had showed up, I called and complained. They sent someone out and he even ran me a fifth wire for future expansion as I requested. All five wires running outside the house, no splitters in the attic. They raised the maintenance fee to $5 the next month, I paid that and cancelled. Now, I have cut the cord and have nice system for my antenna, and a separate coax to my modem.

I'm sorry this line was wrong, where I said speed, I should have said signal strength.

Ya, I have one similar in style to the Apica, If we install new cable, we can use it. I even have a 500 ft spool of the orange cable the company uses for direct burial. I bought it the local metal scrapyard. I suspect someone stole it and then sold it for the copper to the scrapyard, I hope they didn't discard it because it was defective.

I got a couple of splitters from him before he left, one two way,

-3db, and another with -4.5db tap and the rest -7db. I wanted to insert just to drop the signal level a little. The cable guy tried to hard wire the computer, I wasn't there then, I was told they think there is a bad connection in the modem, they had to keep wiggling it to get a connection, but then they would lose it. I said "all 4 ethernet connectors?" No answer for that. So, I also want to take my laptop over and my cable and hard wire it. If it measures slow, I'll suggest we connect the modem outside where the cable comes up out of the ground and see if it has proper speed. If yes, then replace the cable in house.

Cursitor had no effect in my lack of important data.

I did it all myself.

First it was about 36*F outside and I took the garbage out and saw the cable truck, so I wondered over to neighbors to supervise. ;-) I didn't inspect the cable guys meter, it was two parts the measuring device and a separate display. they were both in there bag or holder and I didn't get a good look. By the time we got to a 300MHz bump it was getting dark. If this goes any further, I'll answer 3 or 4 of your 5 questions.

Yes we have that awareness of product speed , and the cable guy got

70 MBPs on his phone. That's still not what he is paying for. As I said he had 200 MBPs, I talked him down to 100 MBPs, saying, "I can stream all 3 firesticks and use my computer without buffering. He only has one TV and his wife's cellphone to deal with. I'll add, I have an old slower laptop, but when I speed test with wifi on that at my home, I get the full 60 MPBs that I pay for.

He has the combo unit now a Netgear.

This is what I like and which might work if approved by the

Cable guy a gave a little push to Arris.

Usually have to call the cable company and have them ping some info to the modem when first installing. Then I'd have to re ping it back at my house. I have a different cable company, not positive mine is compatible with his Comcast service. But I could check.

NetGear, 192.168. 1.1 or 192.168. 0.1

Thanks Jeff, Mikek

Ummm... we were trying to fix your neighbors mess, not yours. Please try not to confuse things (and me) by adding your mess to the soup.

$1 per wire for a service contract. I gotta try that on my next wiring bid to see if it works.

Modem as in cable modem? Just curious.

Just ignore what I scribbled about having found the problem in the neighbors wiring. However, this gives me a chance to try out my new service "Remote Viewing and Diagnosis" where I sit in a contorted yoga position, and try to visualize the problem. In my minds eye, I see your neighbors cable wiring to be a tangle of rotting cables and badly installed F connectors. Viewing the scene with my crystal ball results in the same image, thus confirming my diagnosis. In order to fix it, simply replace everything.

The Aprica compression connector tool is a problem. It's designed to fit exactly one size of F-Connector. Each manufacturer has a different size so as to lock in their larger customers into only using their connectors and tools. I suggest you use Belden SNS1P6U (red) connectors: You should be paying about $0.50 per connector. I prefer the orange handle tool, which fits literally everything (including BNC and RCA phono connectors) but does require some fiddling with the adjustments to work correctly. Hmmm... I can't find it again on eBay. This looks like a better version:

Orange is for TEMPORARY cable drops.

Temporary cable is usually not waterproof (gel filled and non-penetrating jacket).

The two way (-3.5dB) is a splitter. The other one might be a cable tap (directional coupler). You can probably use the splitter as a

-3.5dB attenuator if you put a 75 terminator on the unused port.

He's probably correct. I've seen it all too often. Some drops the cable modem with the RG-6/u coax attached. It lands on the F-connector and breaks the connection inside the tuner. That's usually easy to fix. Tear it apart, lift the lid on the tuner, survey the damage, and solder it back together. Extra credit for securing the F-connector with epoxy (or hot melt glue).

I can see why. Next time you write "bad connector", you might find it more intelligible if you specify which connector. I'm assuming the F-connector, but it looks like the unspecified modem is actually a cable router or "gateway".

Probably a good idea. Wiggle "the connector", any connector and see what happens.

Yep. The idea it to plug into the unspecified ISP's cable at the point of entry so as to eliminate the entire house and everything in it.

FON (fear of numbers) must be contagious. You can check if you have FON. Just count how many product names, model numbers, version numbers, measurement numbers, in your posting. If it's tiny compared to the number of lines in the posting, you're doing badly and are infected with FON. If all you see are numbers, then you are suffering from hyper-FON, and are spewing too many numbers. An average of one number per line is a good compromise.

Got it. The garbage attracted the cable truck. I'll try that next time the cable guy is late.

At what temperature do you start functioning normally?

I don't think it can go much further. I still don't know what equipment you're working with or the basic system details.

That would be via wireless. So, the cable speed could 70Mbits/sec or faster as the wireless connection is now the slowest part of the system.

You won't get 200 Mbits/sec on a wireless smartphone. 802.11ac can theoretically do 500 Mbit/sec, but all I've seen is about half of that.

He has 3 Amazon Firesticks. One for the TV, but they don't fit in cellphones. Where to the other 2 Firesticks go?

If you feel the urge, plug your fastest machine into a gigabit port on your router, and run iperf3 -s to setup an iperf3 server. Then run iperf3 on one of your machines and speed test you wi-fi and ethernet speeds. That takes the speed of the cable out of the picture and only measures the speed of your hardware. It should be faster than 60 Mbit/sec or it's NOT your cable ISP that's slowing you down: More:

Drivel: I've been replacing older routers (i.e. Linksys EA2700) with newer routers because they can't deliver the speeds that Comcast is now providing. I've seen 300 Mbits/sec recently and the EA2700 can barely deliver 90 Mbit/sec.

Find a suitable recycler and buy a new modem (SB6190) and a separate wireless router (Asus RT-AC68u with 802.11ac or better). He won't like the price on the router, but methinks it's worth the price.

Arris/Motorola have their problems, but I think they're good enough and generally better than most. I buy quite a bit of refurbished hardware including refurbished Arris cable modems. I have received some lemons, but have always been able to exchange it for one that works. Just be sure to update and test it on arrival.

Baloney. When you swap modems or routers with the neighbor, the cable company thinks that the modem is still at his house. Nothing to change or reset. The unspecified cable company has no way to know if the modem is at the neighbors house or at your house, as long as you're both on the same ISP, CMTS, and segment.

Wrong. Also, ping is a latency test program, not a programming tool.

Hold it. If you have a different ISP, you can't move a modem or router to another ISP. Got any more details you failed to mention that might be important. If not, please cease mentioning your setup as it just confuses the issue. We're trying to troubleshoot the neighbors networks, not yours.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

It' a modem I connect to the cable to get internet. Cisco DPC3010, my router is a TP-Link AC1900. My daily driver is a 1997 Toyota T-1000, Ok I'm just playin with you on the last one!

Still in troubleshooting mode, replace everything is last resort. First thing, I'm going to try is reducing the signal strength. I know that is not high on the probable list, but I got other feedback that over driving a modem can slow them down.

It's always something.

Around here it gets buried after laying in the yard long enough to generate enough complaints. After I cut my neighbors cable while installing a sprinkler line, ( I called to report it, they said they'd wait until it came from their customer.) It took almost a year for enough water getting in to generate the complaint. Then they laid the oraange wire from the box in my yard across the neighbors driveway and into the house. We mowed over it for 9 months before I buried the part in my yard, and it still runs across the neighbors drive more than 2 years later.

I fixed more than 100 of those torn out F connectors on VCRs.

You need a mind reading course! No it was the ethernet connectors, it has 4 of them. I talked with the neighbor today, he said they actually tried all 4 connectors and all

4 did not work properly.

I was at the house when my neighbor called the cable company, they went through several procedures trying to fix his problem and couldn't. They said because your such a loyal customer (ahem) we want to send a truck out today, will between 3 and 6 be OK. Great. So they never showed up. He called the next day and they did show up.

Do you mean now or 30 years ago? My wife might even question if I ever function normally.

OK, I gave out useless info, I'm the one with 3 Firesticks. He has one TV with a firestick and his wife's phone, also has a laptop, but not used much.

WE aren't with the same company.

My neighbor is a Southerner and talks pretty slow, sometimes hard to understand. I played interference to help the cable people on the phone. When I was showing him how to use the remote on the Firestick, when we got to Alexa, I said, "push that button and name a movie." He pushed it and in his Southern drawl named what I expect was a movie. I reacted by saying, "give me that remote, she's never going top understand what you said," and she didn't. I was a little embarrassed at what I said and his girlfriend/wife was sitting in her seat laughing about it. Other than that, nothing to add at this time, he gets Mondays off, so, I'll know something after that. Thanks for your patience and your fountain of unending knowledge, Mikek

I've often wondered why techs hardly ever use crimp tools for F connectors when they're finished hooking up coax. Then, everything is well shielded from the outside stuff. Unless they lost one and don't want to buy a new compression tool.

Y're mixing up crimp and compression connectors. This is a crimp connector, which should be avoided: If you see one of these, cut off the crimp connector and replace it with a compression connector.

These are various Belden/T&B compression connectors. The video explains how it works: "Belden SNS1P6U Ultimate F-Type Snap & Seal - RG6 Universal" (1:41) Unless I run into something really strange, I use the "red" compression connectors, which fit most of the common stuff. Notice in the video how the metal connector and the plastic sleeve are compressed with the tool to grip the coax. That's what holds the connector together so that no crimp ring is required.

The strength of a compression connector is good enough to survive someone tripping over the cable and possibly survive a 2 year old with a bad case of "grabby paws". Unfortunately, it's also stronger than whatever holds the F-connector in place inside the set top box, modem, DVR, TV, etc. The result is instead of the connector sacrificing itself so that the set top box will survive, the F-connector receptacle breaks from its mounting inside the tuner can. I carry a few of these push-on adapters, which I install in locations where I'm sure the resident big foot is going to trip over the cable.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

You use words oddly. Please get someone to redo your post.

That makes no sense.

You snipped the context. 5 new coax cables were run from the outside through the attic to F connectors in my house. When I cut the cable, I repurposed 4 of these coax cables for use with my antenna. The fifth coax I connected to the cable and it runs to my modem for my internet service.

Mikek

If you want to pick out any particular lines I could probably help you. If it's just the last few lines,

The signal level going into the modem was right at the top of the recommended high, so I want to know if overloading the modem will cause it to run slow.

Rather than have my neighbor go out and spend his money on a new modem, I want try a few things before he spends his money on a new modem.

Mikek

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The usual setup is to use a selected tap from the cable TV drop to get the right level. The trough leg must be connected to a set top box, or a 75 ohm terminator. If it is, then see what the insertion loss is for the tap and get one 3dB higher. For instance, if it is marked 17, replace it with a 20. In a former life, I designed CATV systems

I don't know where I left off in this sad tale, but just an update. Not sure I want any advice, because I don't have all the numbers! I'm sure the order of some of the details are mixed up.

Neighbors has buffering on his 1 yr old Samsung 4K TV while watching on NETFLIX. First cable guy left after changing one barrel connector, he did many speed tests and the best he got was 70MBPs, with a 100MPBs service. He suggest the modem/router could be the problem. Computer shows speeds of 5GBPs to 38GBPs. Cable guy blames slow speed of the computer on the computer.

Neighbor bought a New Netgear C7000v2, and connected it, called the cable company (Comcast) and they could net recognize the modem/router. The called Netgear trying to resolve the problem and then after an hr on the phone they hung up, we were on hold at the time. Neighbor went and bought a second router with a separate modem. He did manage to get that to work but it was also slow, even with a ethernet connection. New "highly experienced" cable guy comes. Though he spends about 3 hrs at the house, and reboots everything and reinstalls any info needed in to the original Modem/router "Netgear C7000" and the Samsung TV, (UN65NU7100FXZA) While testing with his phone he manages to get 100MBPs on a few occasions, and much less (under 50) on many other occasions. Speedtesting on the TV and the maximum he ever got was 32MBPs, and many tests under that.

Also cable guy says call NetGear and have them combine 2.4 and 5GHZ and the TV will work better. HUH!

Cable guys leaves, without, as far as I'm concerned fixing the problem.

OK even so, my neighbor calls Netgear to combine his 2.4 and 5GHz They tell him the Netgear C7000 was made in 2016 and they will not cover that, he can but a 1 yr service agreement for $138 or 2 yr for $220, he gets pissed and raises hell with them and they hang up. When he gets off the phone, his internet is out. So he calls Netgear back, gets a new person, explains it all and the rep turns his internet back on. Now that really sucks.

Then the cable guy finds that on Samsung TV, 5GHZ is non functional and says the problem is the wifi card is bad on his TV. Cable guy also said that 2.4GHz wifi will not do 100GBPs, my info is 2.4GHz will work at 450MBPS and even higher under best conditions.

Neighbor calls Sansung trying to get them to fix the 5GHz wifi and they UNcombine the 2.4GHZ/5GHZ combine. That will fix your problem, We do it all the time.

Now through all this, wife/girlfriend whats to rearrange the furniture. So, we run a new coax to the corner where she wants the TV. Since the TV router is in the back room we move the router out to the TV room where almost all of the above tests were run.

The next step is to run one more cable from outside and end it an the same box of the new cable just run. One will be internet and one will be antenna. Now the modem/router will be next to the TV, and the TV will have an ether net connection to the router/modem.

Update next week.

Mikek

Those packages are sold as 'Up to' speeds, not guaranteed speeds.

38 Gigabytes per second? REALLY?

Error, ya that should have said 5MBPs and 38MBPs.

Mikek