Post #411,861
7/16/16 10:21:27 AM
7/16/16 10:21:27 AM
|
If I bypass a 4-way splitter amplifier, the network works...
Our house has at least 4 TVs, so there's a mass of passive splitters scattered around. There's a 2-way passive splitter outside (half to an upstairs bedroom, half to the main part of the house), and I have a 4-way active amplifier splitter where one leg enters the house. Without some sort of amplifier, at least a couple of the TVs don't get a decent signal. I've tried 3 different brands of active amplifiers, with and without special modem ports, with the same results.
On bypassing the 4-way splitter amplifier now, the network works just fine, but of course, the TVs don't.
I guess this means I need to put the 4-way splitter amplifier outside and get the signal directly from the pole. Of course, to gain access to that, I have to trim back some shrubbery, get on a ladder, then run a powered coax line (meaning I have to drill a hole through the foundation, etc., etc.).
(sigh)
Maybe it'll start working again on its own and I won't have to mess with that this weekend.
Fingers crossed.
Cheers, Scott.
|
Post #411,863
7/16/16 10:44:39 AM
7/16/16 10:44:39 AM
|
You might need to make a service call.
This reminds of the first cable modem I installed for my brother. It was a DIY kit from his cable provider Suddenlink.
I just could not make it work. So, we called for their service tech.
There was definitely a signal strength problem. He replaced splitter and coax connectors at the house. That improved the TV (analog) signal noticeably, but the modem was still unhappy. He then went looking for the feeder line out in the street and replaced the connections there and that did the trick. Corrosion and weathering takes its toll over the years.
Alex
"There is a cult of ignorance in the United States, and there has always been. The strain of anti-intellectualism has been a constant thread winding its way through our political and cultural life, nurtured by the false notion that democracy means that "my ignorance is just as good as your knowledge."
-- Isaac Asimov
|
Post #411,871
7/16/16 12:51:36 PM
7/16/16 12:51:36 PM
|
I know, but that's always a pain.
When they've diagnosed things over the phone, e.g. a few weeks ago, there's never a problem on their end, nobody in the neighborhood reports problems, signal levels seem fine to them, etc.
One time they came out and said something was introducing a bunch of noise and I swapped out a passive splitter and that seemed to help. (I can't figure out why a passive splitter would add noise (it should just attenuate), but there you are.)
I really can't spare the time from work to sit around waiting for them to visit during the week, either. :-(
There was a time when I was still in an apartment that my phone would always go dead when it rained. It took about 3 visits for them to finally fix the problem on the pole. :-/
I'll see what I can do outside this weekend. If it's still problematic, then I'll have to bite the bullet and have them visit.
I would like to think that optical fiber wouldn't have these weather/degradation issues, but I know that there are always special connections that can degrade with time (as ozone attacks the plastic, etc.) and there are various optical repeaters along the path, also too. There's no guarantee that it's any more reliable in the real world even though it should be...
Wish me luck!!
Cheers, Scott.
|
Post #411,866
7/16/16 10:58:53 AM
7/16/16 10:58:53 AM
|
Can you redesign inside?
i.e. run a leg from the outside 2 way splitter straight to the modem, then use an active splitter on the other leg to pick up the disconnected cable?
Things are getting very fickle with signal strengths. We have the inverse problem in winter: in cold weather, Comcast's signal exceeds the upper limit and while our modem is OK with that, their TV set top box is not.
You would need to get your hands on a Time Domain Reflectometry tester to sort out where the dud connection(s) are.
|
Post #411,870
7/16/16 12:41:44 PM
7/16/16 12:41:44 PM
|
Probably.
I like your idea of using the 2nd leg of the external splitter as a dedicated line to the 4-way amplifier, keeping the network alone on the other dedicated half. That should be easy to rig up (a coax cable is already there - the analog cable was originally 2 coax lines). As long as the existing cable isn't too degraded, it should be a pretty easy fix. But something's definitely not right outside. On coming back from the walk with Sophie, the network had stopped working again... I had to reboot the modem again and reset the router... Would one of these Fluke TS-54-TDR jobbies help in my case? It's about $487 at Provantage. That would be painful, but within the realm of possibilities, and if it saves me from pulling my hair out or wasting another few weekends, it would be worth it. It's a lot better than $10k!! But if it really wouldn't help diagnose the problems, I have better uses for $500... :-/ After I cut the grass, I'll see about getting up on a ladder and working on the cables... Thanks. Cheers, Scott.
|
Post #411,923
7/18/16 11:36:49 AM
7/18/16 11:36:49 AM
|
I had access to one through work
A portable jobbie like the Osborne 1 was portable...
Any TDR should be able to show you the impedance changes on the cable. The TS-54 you mention is geared towards telephone use. It may no do much good if you need to get down to measuring actual signal strengths.
|
Post #411,924
7/18/16 12:23:48 PM
7/18/16 12:23:48 PM
|
Thanks.
I downloaded the Arris/Motorola Surfboard 6141 manual and will look at what it thinks is going on when I get a chance. With any luck, there will be some useful signal level numbers...
Thanks.
Cheers, Scott.
|
Post #411,928
7/18/16 6:57:46 PM
7/18/16 6:57:46 PM
|
If Cox is anything like Comcast...
The Surfboard 1500 made the readings available but Comcast reprograms it as soon as it connects to the cable. From that point on, bye-bye readings. (SNMP to the cable side is blocked out as well.)
|
Post #411,930
7/18/16 8:02:30 PM
7/18/16 8:02:30 PM
|
Seems to be working here.
The log started working around 4:30 PM today - before that the date is Jan 1, 1970. There was a big line of thunderstorms that came through this afternoon...
Everything seems normal and accessible in the modem - it says I've got 0 to -1 dBmV down, 57 dBmV up.
I assume the next time it crashes, I won't be able to access any sensible information...
We'll see. At least I can try to look at some numbers now!
Cheers, Scott.
|
Post #411,877
7/16/16 4:46:00 PM
7/16/16 4:46:00 PM
|
Bingo.
It wasn't as hard as I feared to get to the outside splitter. I ran the upstairs leg back down to the main wiring point, put the 4-way splitter amplifier on it, kept the modem on the non-amplified leg, and we have Internet and TV simultaneously again.
Yay!
(Part of the leg going to the upstairs was on a splitter that had a coax cable ripped away, so who knows what that was doing to the signal.)
Of course, I found a couple of ~ 1/2" gaps where the siding and trim has moved away from the house that will probably have to be fixed by some siding people, so there's that... :-/
Thanks!
Cheers, Scott.
|
Post #411,882
7/16/16 7:27:14 PM
7/16/16 7:27:14 PM
|
Yay! indeed, plus one I forgot
Check all splitters, including the outside one and make sure they say they'll go up to 1GHz. The ones that do not state that are likely to attenuate the upper reaches of the band and that is where the modem signal lives.
|
Post #411,883
7/16/16 7:33:27 PM
7/16/16 7:33:27 PM
|
Woot!
"Unterminated" coax causes frequency dependent reflections back to the splitter and beyond. So, yeah, it doesn't help! :)
Alex
"There is a cult of ignorance in the United States, and there has always been. The strain of anti-intellectualism has been a constant thread winding its way through our political and cultural life, nurtured by the false notion that democracy means that "my ignorance is just as good as your knowledge."
-- Isaac Asimov
|