Fixing Intermittent Cable Modem Points

2023-05-20 04:22:21

Do you will have an intermittent cable modem Web connectivity downside?
Is your Web connection working more often than not, however dropping sporadically
and periodically (like solely throughout the center of on daily basis)?
Is VoD on cable set high containers additionally impacted on the similar time?

Test to see if cable modem channel “Suckout” and/or “Unfastened/Unhealthy Connectors” are the issue.
These are issues YOU can test (and with unfastened connectors, repair) your self.

Even seemingly minor ‘unfastened connectors’, or connectors not screwed on absolutely, or improperly put in F-connectors
— can surprisingly be a serious reason for intermittent cable modem points (see video proper)

The underside line:
Many cable modem Web issues are finally attributable to unhealthy/unfastened cable/connector points, which
you possibly can resolve youself. And that’s what the remainder of this paper is all about — offering you with
the data wanted that can assist you to resolve cable modem Web connectivity issues your self.

FIRST STEP:
Step one is to substantiate that the cable modem (and never one thing else) is definitely having issues.

This step is necessary, as a result of in case you are experiencing Web connectivity points,
however the cable modem log exhibits NO points, possibly the issue is along with your
router, Wi-Fi, or one thing else?

But additionally be sensible. Should you do not discover Web points, don’t fret that a lot about
what you discover within the cable modem diagnostic net pages.

Cable Modem Diagnostics Webpage:
ALL cable modems ought to have a diagnostic webpage, typically at http://192.168.100.1,
or http://192.168.0.1 that
shows all types of invaluable info like (1) downstream channels/energy/SNR, (2) upstream channels/energy,
(3) occasion logs, and so forth. that can help find issues and confirming fixes.

TIP: Google the model and mannequin variety of your modem and ‘handbook’ (eg: “Netgear CM1000V2 handbook”) to
discover the handbook on your modem, which ought to disclose the IP deal with to make use of to get to the diagnostics
webpage on your cable modem.

TIP: For unknown causes, once I manually energy cycle my Netgear CM1000 cable modem (on Comcast), after reboot,
the diagnostics net web page is inaccessible. Nonetheless, if I disconnect the RG6 cable from the again of the modem,
and reconnect it a minute later, the cable modem diagnostics net web page can as soon as once more be accessed
(and naturally, you should ignore among the errors within the occasion log attributable to disconnecting
the RG6 cable).

►Occasion Log:
First, discover and study the cable modem occasion log. You wish to decide in case your cable modem
is complaining about something ‘essential’ regularly. Rare messages are nothing
to fret about. However frequent or periodic error messages (like on daily basis) signifies that one thing is probably going flawed.
Ideally, you need an occasion log that’s all the time ’empty’ — which means that the cable modem
is in steady/dependable communication with the CMTS (“Cable Modem Termination System”
– the cable firm gear that your cable modem communicates with).

You might be on the lookout for any common/frequent essential/warning log entries like the next:

Began Unicast Upkeep Ranging - No Response acquired - T3 time-out
No Ranging Response acquired - T3 time-out
T4 day out
Dynamic Vary Window violation
RNG-RSP CCAP Commanded Energy Exceeds Worth Comparable to the Prime of the DRW
RNG-RSP CCAP Commanded Energy in Extra of 6 dB Under the Worth Comparable to the Prime of the DRW

But additionally, be sensible. Errors within the occasion log are solely ‘unhealthy’ in the event you discover an impression on
Web connectivity. For me, the errors made enterprise video convention calls unworkable
and VoD on two-way cable containers in the home would error out in the course of watching packages.
Very annoying and really impactful.

Once more, you might be on the lookout for frequent (on daily basis or so) essential errors within the cable modem occasion log.
It’s typically NOT thought of an issue to see one essential error every week, or common ‘discover’
messages within the occasion log.

After bypassing all home wiring (part beneath), the expectation is that
frequent messages within the occasion log ought to ‘go away’.
If not, this means a problem ‘someplace’ with the cable firm.

Downstream Energy (dBmV)

►Downstream “Energy”:
Signifies how highly effective the sign is from the CMTS to your cable modem.
The ‘perfect’ goal worth is 0 dBmV. Larger (constructive) numbers means
a extra highly effective sign. Decrease (detrimental) numbers imply a much less highly effective sign. The most effective
vary for a cable modem to function in is from -7 dBmV to +7 dBmV, however the cable business
says cable modems ought to nonetheless work ‘superb’ inside a spread from -15 dBmV and +15 dBmV.

If energy ranges are low (lower than -11 dBmV), examine why and repair. Is your modem
behind too many splitters? On the cable demarc location, there ought to be a single 2-way
splitter feeding (1) the cable modem and (2) the remainder of the home by way of one other passive
splitter. See part far beneath on a ‘powered amp’ various.

If energy ranges are too excessive, or ‘scorching’ (higher than +15 dBmV), contact your cable firm to resolve.

Additionally, all downstream channels ought to have ‘comparable’ “Energy” and “SNR” values (all ‘Energy’ inside 3 dB of
one another and all ‘SNR’ inside 3 dB of one another). If not, this ‘imbalance’ might point out a
“suckout” downside (see part additional beneath). Here’s a ‘good’ instance with no issues:

After bypassing all home wiring (connecting the cable modem to the cable
demarc location; part beneath),
the expectation is that downstream energy ought to be throughout the 0 dBmV to +15 dBmV vary.
If not, this (doubtless) signifies a problem ‘someplace’ with the cable firm
(specifically, why is the cable firm not offering a robust sign to the house).

Downstream SNR (dB)

►Downstream “SNR”:
The upper the quantity, the much less ‘noise’ there’s (relative to the sign)
— so the higher the ‘sign high quality’.
For QAM256 (the modulation seen within the instance desk above), you wish to see a minimal SNR of 33.
However greater than ’33’ could be very typical, like within the 37 to 39 vary (like in desk above, it’s above 41,
which is superb).

SNR is an acronym for “Sign to Noise Ratio”.
MER is an acronym for “Modulation Error Ratio”.

SNR is “what number of dB above the ‘noise ground’ the sign is” and successfully indicating
how nicely the sign is heard above any noise.

An analogy: Should you discuss usually to somebody at house, they’ll simply hear/perceive you as a result of there
is just about no noise — so the SNR could be very excessive. Nonetheless, in the event you discuss usually with somebody at
a bar, they’ll barely hear/perceive you as a result of there’s a variety of background speaking
(noise) — so the SNR could be very low. It’s good to converse a lot louder to get ‘the sign’ above
the ‘noise ground’.

After bypassing all home wiring (part beneath), the expectation is that
downstream SNR ought to be glorious.
If not, this means a problem ‘someplace’ with the cable firm.

How does your SNR examine to everybody else? Comcast in 2013
published
the Downstream SNR values seen in a pattern of 20 million cable modems and acquired the next graph.
The underside line is that in case your SNR is above 36.4, then your SNR is “above common”.

Upstream Energy (dBmV)

►Upstream Energy:
The decrease the quantity the higher (inside motive). That is the
energy stage that the CMTS has instructed the cable modem to transmit at to ensure that the
modem’s sign to be acquired by CMTS with an influence of 0 dBmV
(source).
Anticipate to see upstream energy ranges between 35 dBmV and 48 dBmV, which is ‘regular’. Something
above that and the cable modem is beginning to ‘shout’ on the CMTS and that’s undesirable
(and sooner or later, it now not works nicely).
Here’s a ‘good’ instance with no issues:

The ability stage for all particular person upstream bonded channels ought to all be inside 3 dB of one another. If not,
there’s a downside to seek out. First consider all home wiring (see remainder of this paper). If that
doesn’t repair, contact your cable firm.

IMPORTANT: Anticipate upstream energy ranges to be regular/constant (inside roughly 1 dB)
all through your complete day.
Massive jumps/spikes abruptly of three+ dB in any channel is NOT regular and is a
very robust indicator of issues (like unhealthy cables, unfastened connectors, noise ingress, and so forth.
see sections beneath). Under is a graph of most upstream energy seen by my cable
modem over ten days, sampled each minute. The ‘spikes’ in upstream energy (of 8+ dB) correspond to
Web connectivity issues, with numerous essential errors logged within the cable modem occasion log.
Discover how every thing was good/flat for the primary couple of days, after which acquired unhealthy.
Additionally, now that my issues are fastened, the graph of ‘Upstream Energy’ is now all the time ‘flat’.

When upstream energy is simply too excessive, once more the query is: Is there a nasty cable? Or, are there
too many splitters between the modem and the cable firm? See the part far beneath
on powered amps.

See the part far beneath on the anticipated dB sign lack of cable size
and splitters. The cable modem wants to extend upstream energy by the dB lack of all
splitters between it and the cable firm. So you possibly can instantly and immediately
enhance (scale back) upstream energy by discovering a approach to take away splitters between the modem
and the cable firm.

After bypassing all home wiring (part beneath), the expectation is that
upstream energy ought to be nicely throughout the 35 dBmV to 48 dBmV vary.
If not, this means a problem ‘someplace’ with the cable firm.

►Correctable/Uncorrectable Codewords for downstream QAM channels: The
final aim is for these numbers to be zero (or successfully zero). It’s attainable.
The reason for correctable/uncorrectable codewords is RF ingress, or noise, interval.
So in the event you see these numbers improve regularly (test earlier than/after an
Web velocity check), you KNOW you will have
a RF ingress (noise) downside to repair. Probably causes are unhealthy or unfastened connectors,
unhealthy cable, and so forth — anyplace in the home (see the remainder of this paper).

Conversely, in the event you see NO uncorrectable errors and successfully zero correctable codeword
errors (like 1 in 100,000,000), that the cables, connectors, splitters, and so forth
in the home are in nice form.

I’ve a number of areas the place over an prolonged time frame (like every week),
there are NO ‘uncorrectable’ codewords (sure, none), and the variety of ‘correctable’
codewords is so extremely low (one in a billion) as to successfully be zero.
But additionally be sensible. Should you see codeword errors, however will not be noticing any
Web points, don’t fret in regards to the errors (one thing I’ve at different areas).

Please word this dialogue solely applies to QAM channels, not OFDM channels.
As a result of with OFDM channels, seeing ‘correctable’ codewords is regular.

After bypassing all home wiring (part beneath), the expectation is that
codeword errors will likely be successfully eradicated.
If not, this means a problem ‘someplace’ with the cable firm.

Downstream/Upstream Energy Ranges balancing act: Discover that what number of (or few) splitters there are
between the cable modem and the cable firm straight — however inversely —
impacts each downstream and upstream energy ranges.

Including a two-way splitter into the modem run will trigger downstream ‘energy’ to lower
by 3.5 dB, however trigger upstream ‘energy’ to improve by 3.5 dB.

And conversely, eradicating splitters within the modem run will trigger downstream energy
to improve by ‘X’ dB, however upstream energy to lower by ‘X’ dB.

SECOND STEP:
The second step (after confirming a cable modem downside; part above),
is to level the finger and blame both the cable firm (name the cable firm to repair),
or home wiring (first, attempt to repair the difficulty your self; as a final resort, name the cable
firm for assist).

But additionally be careful as there could also be issues with each cable firm
wiring AND home wiring.

100ft RG6:
Spend $15 (Amazon) and get a top quality 100-foot indoor/out of doors tri-shield RG6 cable
(or no matter size you should make the check beneath work) and join your cable modem
on to the cable line feeding your home
(this bypasses ALL home cabling, connectors, splitters, and so forth).

Notice that during this check that your Web will work,
however all different cable related containers will likely be offline.

CATV whole-house feed within the cable demarc field

Purpose: The aim is to disconnect your total home from the cable firm, and run a
NEW (momentary) RG6 line all the best way from the road feeding your home (on the cable demarc field at
the aspect of your home) to ONLY your modem (and nothing else) and see if the issue stays.

Do NOT use any splitters or different RG6 cable, and don’t splice smaller size cables collectively.
You need a direct connection out of your cable modem to the RG6 feed offered by the cable
firm utilizing solely a single model NEW RG6 line.

Search for a grey cable field on the surface of your home the place utilities
(electrical / cellphone / cable / fuel / and so forth) enter your home (the demarcation — or ‘demarc’ — location).

It is best to see a cable demarc field with an typically thicker cable line from the cable firm
(orange cable in picture higher proper)
feeding right into a ‘floor block’
(and built-in MoCA filter; generally put in by cable corporations),
which then feeds a
line feeding the remainder of your home (white cable in picture higher proper). The ‘disconnect/reconnection’
level is simply previous the ‘floor block’
(for an instance, see crimson arrow in picture higher proper).

Another excuse for testing utilizing solely a NEW RG6 cable from the modem to the demarc location
is to eradicate the opportunity of a broken/unhealthy cable someplace in the home/partitions (like throughout
development a nail hitting a cable line).

100ft run on to cable modem

Potential Outcome One:
In case your Web issues go away (see part above to confirm), then that factors the finger at home
wiring because the supply of the issue.
Attempt to repair the issue your self first (fastidiously study every cable run as per the remainder of this paper).

The expectation (when your cable modem is straight related to the cable firm demarc location)
is that downstream energy ranges are ‘excessive’ (above 0 dBmV) and that upstream energy ranges are
‘low’ (nicely beneath 45 dBmV).
If not, is the cable firm not offering correct indicators to your decmarc location?!

Potential Outcome Two:
Or, if an issue stays (after bypassing your total home), then you definitely KNOW there’s a
downside ‘someplace’ and with the cable firm (however one other uncommon chance is a nasty cable modem).
Name the cable firm to repair.

WARNING: Discovering an issue ‘someplace’ with the cable firm does NOT eradicate the
chance that there might ALSO be secondary points with home CATV wiring.
That is what occurred at my home. There have been quite a few issues, each with the cable
firm wiring AND with the home cable wiring.

TIP: If there’s a downside after bypassing home wiring, leverage that truth to
get a free tech go to to repair that downside. However when the tech arrives, inform them how
you examined and what you discovered, however emphasize that you simply additionally need the tech to confirm
that each one home wiring is OK as nicely.
Doing this most likely would have saved me a few later tech visits. As a result of as
quickly as I mentioned I bypassed all home wiring and nonetheless discovered an issue, the tech ignored
all home wiring (and missed discovering a secondary downside in the home).

“Divide and Conquer” to isolate the issue half:
Generally, the “Divide and Conquer” method is how you can discover
the basis reason for any downside. Take away/Bypass a component (round half) of the gear/cables/and so forth
and see if the issue stays. If that’s the case, repeat. If not, transfer to the opposite half.
Ultimately you can be left with solely the issue half.
OR, begin with a working setup, and slowly add components again in till
the issue reappears (after which blame what you simply added again in). It might take some
time and endurance, however you will see that the issue.

That is how one individual discovered that an improperly grounded splitter was the reason for
issues. Any ‘grounding’ wire related to a splitter should be correctly related
to a grounding rod driving into the bottom, and never related to one thing else
(which can not itself be correctly grounded).

THIRD STEP:
The third step is for YOU to examine all in-house wiring and take motion
(see sections additional beneath) to repair issues which can be discovered.

Examine every thing:
No matter the results of the ‘bypass the home’ check within the part above, plan to take
the time and carry out a full essential inspection of each cable run in every single place, and
the connectors on these runs, particularly the connectors behind wall plates (see sections
beneath) — and proper any issues discovered.

Within the technique of doing this, I discovered a nasty splice in a run by the attic house.
Whereas there ought to by no means be splices in runs, I can solely assume the run was broken throughout
development, and the one repair accessible was to splice the road (it was too late to put in
a brand new run).

I additionally mapped all runs in my home and labeled all cables, as a result of I needed to substantiate
that every ‘run’ solely ran to a single location and system. Ideally, there ought to
be no splitters within the house feeding a number of areas/rooms/units, however the actuality
is that generally they can’t be prevented (when a house was not correctly wired when constructed).

When cable modem downstream energy ranges fluctuate by greater than 3 dB between all channels, the
downside could also be one thing the cable business calls “suckout”.

“Suckout” Outlined: A “Notch within the frequency response affecting a number of channels,
attributable to unfastened modules, module covers, printed circuit boards, poor grounding,
and comparable issues inside energetic or passive system housings.”
See source for this definition
and second source.

Some on-line feedback additionally recommend that temperature variations, inflicting unfastened out of doors
cables to broaden/contract, will also be a root reason for suckout.

Suckout Instance: For my modem, I used to be getting a serious energy imbalance between downstream channels. Graphing
the “Energy” stage for every cable modem downstream channel
(necessary, type by MHz/frequency, because the record offered by the modem will very doubtless be ‘out of order’)
confirmed a important
‘notch’ or ‘suckout’ (an enormous dip or valley) for the primary channels:

Subtract the minimal energy stage seen (for any/all channels) from the utmost energy stage seen.
From the above graph, this worth is 8 – (-9) = 17. That is WAY too massive. As an alternative,
the consequence ought to have been below 3 (a lot nearer to zero; instance beneath).

Should you see a ‘suckout’ downside, even after bypassing home wiring (connecting your modem
on to the cable firm demarc location), contact your cable firm.

After the repair: After the cable firm fastened the ‘suckout’ challenge, energy ranges (and SNR)
appeared a LOT extra regular (constant/stage/flat). Here’s a graph of the “Energy” stage for every
downstream channel (by MHz) after the cable firm fastened the issue:

Subtracting the minimal from the utmost yields ‘2’ — an excellent consequence (it’s below 3). The modem
at this location was a Netgear CM1000V2 utilizing 32 bonded downstream channels.

Discover that recognizing “suckout” turns into a lot simpler with numerous bonded channels
(every channel is 6 MHz vast).
With 8 bonded channels protecting solely 48 MHz of spectrum you aren’t very prone to
discover ‘suckout’. However with 32 bonded channels protecting at the least 192 MHz of
spectrum, recognizing ‘suckout’ turns into a lot simpler.

An ‘F-connector’ is the kind/title of connector on the tip of a CATV cable
(for examples, see images beneath).

YOU can have an enormous constructive impression: This part (on F-connector issues) and a following
part (on unfastened connectors) is the place YOU can have a big effect on sign
high quality in your home. Most cable TECH’s will not be going to take the time to examine
each single F-connector on each single cable run in every single place, particularly these behind
wall plates — however you possibly can.

That is what I lastly did in a single house that had intermittent Web points for years
that Comcast TECH’s couldn’t repair. I discovered some horrible F-connector workmanship behind
wall plates, changed connectors (see part beneath on instruments), and eventually fastened the issue myself.

A foul F-connector behind a wall plate in any room in the home can negatively
have an effect on the entire home (and your cable modem).

A TECH got here out to my home and blamed the entire ‘F-connectors’ on the tip of the
RG6 cable runs within the demarc field outdoors of the home, stating that they have been
put in incorrectly.

The cable dielectric was not flush with base of F-connector — many have been
considerably ‘below’ the bottom (see an instance in picture proper) and a few have been ‘above’ the
base.

In any case F-connectors have been minimize off and changed by the tech, the Web downside
improved (however was not gone).

One of many prior Comcast techs, who had simply changed ALL of these F-connectors solely weeks in the past
(in an try to repair the unknown downside), did it flawed, and created this downside.

So a WARNING — not all cable techs know what they’re doing.
And the Comcast tech who made this error bragged to me that he had over 15
years of expertise working for numerous cable corporations up and down the East
Coast. Even lots of the movies on YouTube displaying how you can set up F-connectors
do it flawed (the dielectric is just not flush)!

Methods to test for this challenge: Look inside ALL F-connectors for all RG6 cables in your home.
The cables out within the open are straightforward, however there could also be one behind each CATV wall plate as nicely.
The ‘whitish’ (dielectric) materials surrounding the copper wire protruding
should be completely FLUSH with the underside of the F-connector (see a ‘good’ instance proper)
and you could not see any braiding strands.

As an alternative, if the ‘whitish’ materials is in any respect beneath (instance seen in picture higher proper) — or above —
the underside of the F-connector — the connector was put in improperly, and will trigger
all types of issues (permit exterior RF indicators to enter the cable and create ‘noise’).

Different F-connector ‘workmanship’ points to look out for:

The copper middle conductor ought to stick out round 1/16″ to 1/8″ above the highest
of the F-connector — and any kind of is an issue to repair.
For reference, the thickness of a nickel is simply barely over 1/16″, which is
an important goal distance.
Guarantee that not one of the foil, or braiding strands, are uncovered contained in the F-connector
(instance seen proper). As an alternative, you must solely see the white dielectric and the
middle conductor. Within the picture proper, you possibly can see the place the foil
was pushed in and broke as a substitute of being minimize — the TECH was doubtless utilizing a slicing
instrument with boring blades.
When making ready a cable for including a F-connector, do not let the blade in your instrument
contact (or ‘rating’) the middle conductor. ‘Nicks’ within the middle conductor can truly
trigger points (micro-reflections).
Keep away from extremely tight bends in RG6 cable, which might push the middle conductor
by the dielectric and nearer to the shielding. This could inadvertently change
the 75Ω electrical traits of the cable.
By no means rotate a splitter/submit (or grounding block) onto a F-connector to tighten it.
As an alternative rotate the unfastened finish of the F-connector onto the submit/splitter. The complete level is to
keep away from spinning the middle copper conductor right into a connector. It’s because
connectors have been designed to have the middle conductor pushed in/out,
not rotated in/out.
Gently attempt to twist the bottom of any F-connector on the tip of any cable. A correctly
put in F-connector will likely be compressed in opposition to the cable and will likely be so tight that it
can’t twist. But when it twists in any respect, the F-connector was not correctly put in
— exchange the F-connector.

Anybody can simply exchange RG6 F-connectors, however solely with the proper connectors, instruments and strategies.
However do NOT use “twist on” connectors, and do NOT use “crimp” connectors.

F-Connector Compression Equipment

As an alternative use solely high-quality ‘compression’ connectors, which create a watertight seal.
On Amazon, you could find tons of cheap ‘compression’ kits
(example)
for round $17 that
consists of every thing you should get began (see picture proper):

The compression instrument (left, crimson)
A handful of compression connectors (center)
The slicing instrument (proper, grey)

Please word that these ‘package’ connectors are sometimes supposed for ‘indoor’ use solely
(not out of doors use).

The one different instrument you’ll need is a “wire cutter pliers” to chop the RG6 cable to
the right size, or to chop outdated connectors off to arrange for a brand new connector.

Watch:
Video on how to (in general) install F-connectors (on YouTube)

Premium connectors: As a result of I used to be going to all the difficulty (and albeit, time!) of changing connectors,
I opted to as a substitute use a ‘premium’ connector (and never the package offered connectors). I used
Belden/PPC EX6XLPLUS RG6 Signal Tight
connectors.

TIP: Apply! Take a brief cable usually used to attach a cable field to the wall jack, confirm it
is RG6 cable, minimize off the connectors and follow placing on new connectors utilizing the
‘package’ offered F-connectors. As a result of frankly, you wish to know you possibly can reliably
exchange F-connectors on a follow cable earlier than trying to take action on cable behind
a wall plate (with a set restricted size; very restricted retry makes an attempt).

Utilization TIP: I personally all the time use the slicing instrument to show 1/2″ of the middle conductor
(see picture beneath), examine the ready finish of the cable, push on a F-connector till
the dielectric is flush with base
— after which trim the middle conductor to the ultimate distance (thickness of a nickel) above the connector
— use the compression instrument, and the essential final setp — fastidiously examine the consequence.

The result’s that the copper middle conductor is all the time the identical exact top
(nickel thickness) above the connector for each connector I make.

At all times examine earlier than AND after:
Earlier than pushing a brand new F-connector onto a cable,
carefully examine the ready finish (see instance picture beneath)
for any remaining foil not absolutely minimize off, and for any braiding wires which will have
inadvertently wrapped across the middle conductor when utilizing the slicing instrument
— because it does occur!
After utilizing the compression instrument, examine the ensuing F-connector:
(1) Is the dielectric nonetheless flush with backside of the connector with no foil/braiding uncovered?
(2) Is the middle copper conductor nonetheless a nickel’s thickness (1/16″ to 1/8″) above the
connector? If not, minimize the connector off and take a look at once more.

TIP: The slicing instrument has TWO adjustable two blades 1/4″ aside.
(1) Alter the primary blade in order that it cuts solely the
outer jacket of the cable (and not one of the braiding wire).
(2) Alter the second blade in order that it cuts
most– however not all — of the best way by the dielectric.
If wanted, spin the piece of cable you might be slicing off to interrupt any remaining dielectric
(typically instances, spinning the slicing instrument finally ends up doing this for you).

Vital: The second blade should NOT contact/rating the middle conductor. That is very straightforward
to by chance do, particularly you will have adjusted the blades for one cable after which
transfer to a second model of cable!
So in case you are simply beginning out, follow (in case you have sufficient cable). Put together the tip
of the cable and as a substitute of placing on a connector, in the reduction of extra dielectric and confirm
that the middle conductor is just not scored (you possibly can inform by operating your fingernail over
the middle conductor).
Some instruments also have a notch within the second blade to assist keep away from this downside.

FYI: A Comcast TECH (worker) in October 2021 (in Georgia) was utilizing
“PPC Good Flex” RG6 cable, which appears to be a tri-shield cable.

Unfastened connectors permit for RF ingress (noise) and may trigger
all types of intermittent cable modem issues.

Any connector that’s NOT absolutely screwed onto the corresponding submit (round 1/4″)
or is just not ‘finger tight’ is taken into account a “unfastened connector”.

Should you screw a F-connector onto a submit and it ‘stops’ and is ‘tight’ early,
one thing could be very flawed. Discover out why. As an alternative, the connector should screw on
utterly (round 1/4 inch).
Guarantee that all cables (F-connectors) are screwed onto posts a robust finger tight,
as any unfastened connectors can truly trigger RF ingress issues.
A cable related to a wall plate, however related to nothing — can also be unhealthy. The
uncovered (unfastened and unconnected) F-connector can act as an antenna, permitting for RF
noise to enter the system. If there is no such thing as a system related, there are
cheap ‘cable termination caps’ that may be screwed onto unused posts.

Unfastened connector at floor block

An instance: It isn’t unusual in ‘overhead’ cable installations to see
a ‘floor block’ on the backside of phone pole, the place one cable comes down
the pole from the ‘faucet’, and one other cable is the run/feed underground to a home.

Within the instance seen proper (crimson arrow), the black RG6 cable comes down the pole from the
faucet, and the orange RG11 feeds a home.

Nonetheless, the issue at this location was that the orange connector, whereas
seemingly ‘tight’ on the bottom block, was NOT truly absolutely screwed onto
the bottom block. There was a few grains of sand (or one thing) stopping
the connector from screwing on absolutely.

Signs: The cable modem skilled numerous intermittent T3/T4 errors,
and modem upstream energy intermittently spiked.

And the cable modem log was filled with "RNG-RSP CCAP Commanded Energy in Extra of 6 dB Under the Worth Comparable to the Prime of the DRW" and "Dynamic Vary Window violation" warnings.

TIP: Get an excellent really feel for a way far (round 1/4 inch) a connector should be
screwed onto the corresponding submit — do NOT rely on a connector feeling
‘tight’ to point {that a} connection is absolutely screwed in —
as a result of it could be tight however NOT absolutely on.

Look into any F-connector. The space from the bottom of the connector to the
high of the connector (round 1/4 inch) ought to be the space that the connector
screws onto a submit.

Examine EVERY F-connector, particularly these behind wall plates:
I as soon as discovered a connection behind a wall plate (for a modem having issues) simply barely
touching, and the final individual to the touch/examine that was the Comcast cable tech! Do NOT
assume {that a} connection is ‘good’ simply because a cable tech was the final individual to
take a look at a connection. As an alternative, take all connections aside, examine, and put again collectively.

WARNING: Solely think about using a ‘powered amp’ after inspecting ALL F-connectors in your home
(even these behind wall plates) and fixing any issues discovered — as fixing all unhealthy connectors
first might alone enhance sign high quality sufficient {that a} powered amp is now not wanted.

TIP: Use a powered amp solely AFTER you will have solved your cable modem issues! As a result of
the one drawback of utilizing a powered amp is that any ‘noise’ being generated on any run (inside
the home) will then solely be amplified and presumably intrude even extra along with your cable modem.

If you’re unable to resolve your ‘noise’ downside, do NOT use a powered amp. In actual fact, by sticking
with a non-powered splitter, you might be including ‘attenuation’ to ‘noisy’ runs, making it a lot tougher for
the noise to trigger issues with different runs in the home (like your cable modem).

BUT, when you resolve any noise/cable issues, utilizing a powered amp is an effective way for all units
within the house to acquire the most effective energy ranges which can be attainable.

A ‘typical’ CATV/modem set up

The ‘typical’/beneficial CATV/modem set up:
On the demarc field/location on the aspect
of the home, the feed from the cable firm goes right into a two-way splitter that feeds
(1) the modem and (2) the remainder of the home by way of a passive 2/3/4/6/8 approach splitter.
An instance of this configuration is seen within the picture proper
(in Florida it is vitally frequent for these units to be mounted on the surface of the home, uncovered):

For many houses, this configuration will work greatest. However in the event you house is operating
into issues with sign energy (too many cable containers), think about using a powered amp.

A brand new approach: Bettering CATV sign high quality / SNR: The CATV business now makes
very inexpensive ‘lossless’ 8-port energetic splitters / powered amps
for house use, with built-in cable modem assist.

TIP: Solely use the brand new amps when actually wanted, when both (1) downstream sign ranges
should be improved, or (2) when two-way VoD cable containers are having bother working.

Older ‘one-way’ cable containers will typically instances work simply superb behind a passive splitter.

Utilizing a powered amp is an effective way to make sure that all two-way cable containers
(like Comcast X1) have the most effective likelihood of working correctly in a big house
the place all cable containers are two-way containers.

The important thing benefit these new amps have (over amps made years in the past in the past) is that these
new units are ‘sensible’ and have NO energy loss in each the downstream
(52-1002 MHz) and upstream (5-42 MHz) paths, which is essential for DOCSIS
units, like VoD set high containers, to work.

Many older amps (nonetheless offered as we speak) solely amplified the downstream, and left the
upstream with full (numerous) energy loss, which might negatively impression VoD cable
containers. These outdated model amps have “passive return” and may now be prevented.

Instance: One instance of a new-style amp is the
“Extreme Broadband IPA1008D-RSVF – 8 Way Splitter”
(seen beneath proper) for round $45 to $60 on Amazon.
That is the precise model/mannequin that my cable firm (Constitution/Spectrum) in North Carolina
put in.

So if the IPA1008D-RSV is ‘adequate’ for the cable firm itself to offer and use,
I really feel assured sufficient to purchase/use elsewhere (and I’ve).

Remotely powered:
The IPA1008D is remotely powered by way of a ‘energy injector’ added to one of many cable runs
in the home (after which that powered cable run is related to ‘Output 1’ on the amp).

Modem/VoIP port:
By design, ONE passive port of the amp stays energetic after an influence
outage and all different energetic ports ‘go down’. This one (and solely)
passive port trades round 3.5 dB (of loss) for this characteristic/performance — in order that
modems with VoIP stay on-line and may nonetheless place cellphone calls throughout energy outages
(e911 compliance).

It’s strongly beneficial that you simply join your cable modem (no matter having
VoIP, or not) to the passive port on the amp. As a result of this port additionally bypasses the diplex
filter within the amp (working at 5-42 MHz) in case your cable firm has expanded
the MHz vary used for Web add channels.

When the cable business strikes to DOCSIS 4.x, it’s anticipated that the
MHz vary used for ‘add’ will broaden nicely previous 42 MHz.

Whereas cable modems WILL (ought to) proceed work on any amplified port (however possibly with restricted add speeds)
the noise on the un-amplified return path on the passive port ‘ought to’ be
barely higher (much less) than the noise on the amplified ports — as this avoids
the “10.5 dB loss + 14 dB achieve” return path (see beneath).
I say ‘ought to’ as a result of the essential SNR worth that might definitively reply
this query (how a lot of a noise distinction) is within the CMTS and isn’t accessible to us.
In actual fact, in Maryland, a Comcast tech put in a PPC EVO1-9-U/U and related the
cable modem to one of many amplified ports (not the passive port) — so sure, it really works.

Unused ports: Make sure to put a ’75 Ohm Terminator cap’ on any unused amp output ports.
This helps to cease undesirable RF ingress (that may as soon as once more impression the cable modem).

How these new amps work:
A block diagram representing (typically) how these new amps work
(source):

Discover that these new amps are simply an unamplified 2-way splitter (left block) adopted by
a bi-directional amplified 8-way splitter (proper block; on one leg of the 2-way splitter).

The bi-directional amp amplifies solely “H” (excessive) frequencies (52-1002 MHz) within the downstream
path (cable modem obtain) and solely “L” (low) frequencies (5-42 MHz) within the upstream/return
path (cable modem add).

The “VoIP/Modem” port bypasses the diplex filters — an excellent factor in case you have a cable modem
that operates outdoors of the ‘normal’ add frequency ranges.

Some cable modems (typically primarily based on the Broadcom chipset) expose a ‘Spectrum Analyzer’
interface on port 8080.

Spectrum Analyzer:
To see in case your cable modem gives this characteristic (however your cable firm may additionally deliberately disguise it;
Comcast usually HIDES it),
use an internet browser to entry port 8080 of your cable modem
(typically http://192.168.100.1:8080, or http://192.168.0.1:8080) and chances are you’ll
see the next (after clicking on the ‘Run’ button):

Seeing QAM channels:
And in reality, when zooming into 50 MHz of spectrum and utilizing the ‘peak maintain’ characteristic, the
6 MHz vast QAM channels change into apparent:

TIP:
Or Google your modem mannequin quantity and “Spectrum Analyzer” to see if anybody has posted directions
on accessing the built-in instrument (some modems might use a special port quantity).

Why so priceless: In case your modem has this functionality, that is yet one more
nice approach to see and ensure if there’s ‘suckout’. Simply zoom into the frequencies used
by the cable modem for Web downstream channels, and once more use the ‘peak maintain’
characteristic.

A cable modem reboot CAN generally ‘resolve’ an issue, though the basis downside nonetheless
stays!

Be careful: Throughout a modem reboot, the cable modem might negotiate a completely different
set of channels to make use of, which in flip might keep away from a problematic channel (frequency),
which suggests the issue finally stays and may come again after yet one more modem reboot.

I bumped into this at one location the place generally Web connectivity was horrible, however
at different instances, it was completely superb. It seems that when Web was horrible, the
cable modem was utilizing a particular channel that had a ton of uncorrectable errors, and when
Web was nice, the cable modem was not utilizing the problematic channel.

In the end, the basis downside was tracked all the way down to a single unhealthy cable that was negatively
affecting a really particular MHz vary (the only channel). As soon as the cable
was changed, the basis downside was fastened.

TIP: If attainable, within the cable modem (by way of net web page), set the beginning frequency
that the cable modem makes use of to seek for downstream channels. After each modem reboot,
confirm that the modem continues to be utilizing the identical obtain/add channels. It will
let you extra simply examine if a change you made truly helped
(or if the development was as a result of modem utilizing completely different channels).

Use the cable containers in your home as a poor man’s energy stage meter. Use the containers to establish
the cable runs in the home which can be experiencing ‘an excessive amount of’ surprising loss —
then discover out why, and repair.

Diagnostic Screens:
Most cable Set Prime Bins (STB) have an intensive set of diagnostic screens. Simply Google
‘diagnostic display’ and the mannequin variety of your cable field to learn the way to entry these
screens.

Right here in Georgia (Comcast), for my cable containers, I simply must press/maintain ‘0’ on the
distant for round 5 seconds to get the diagnostic display seen high proper.
In Florida (Spectrum), similar factor, however with the ‘information’ button.

Or, for Comcast X1 containers, maintain ‘Exit’ for 5 seconds, then press the down
arrow (beneath okay) two instances, then press ‘2’. Appears very timing delicate, so repeat
if wanted.

Methods to use for troubleshooting: Tune each cable field in your home to the
SAME channel after which go into the “Tuner Standing” diagnostics web page (instance seen
backside proper).

The “Energy Degree” quantity for all STB in the home (when tuned to the
similar channel — confirm that the “Tuned Frequency” displayed is similar)
ought to be pretty shut (inside a few dB) to one another.
This check solely works when all runs in the home are related to the
similar X-way splitter / amp.

You then attempt to account for variations in energy ranges seen within the STB
diagnoistic screens between runs/rooms by evaluating the distinction seen to the
anticipated loss (see the following part) attributable to variations in splitters and
cable run size between the 2 runs/rooms.

When the facility stage distinction is just not absolutely defined by variations in
splitters and cable size between the 2 runs, then you will have one thing
to research.

The aim:
The aim is to seek out cable runs which can be approach beneath the anticipated dB stage,
as in comparison with all different runs — after which discover out why, and repair the difficulty.

An instance: In my house, one room actually stood out in a nasty approach — the Energy Degree
was 7 dB beneath all different rooms.
Throughout my inspection of all F-connectors behind wall plates in the home, the
downside in that one room turned apparent:

There was a splitter behind one of many wall plates feeding an unused second
location in the identical room. So the splitter was eliminated.
All F-connectors behind the wall plates on this one room had the identical very severe
downside — the dielectric was WAY beneath the bottom of all connectors.
So all F-connectors have been changed.

As soon as these two fixes have been made on this one room, the “Energy Degree” reported by the STB
tuner diagnostics display was 7 dB greater (on par with different rooms in the home)!

However extra importantly, these unhealthy F-connectors have been virtually actually having some
impression (micro-reflections, and so forth) on the remainder of the home (and impacting the cable modem)
— in order that downside was fastened.

Cable Loss: Generally, the attenuation (dB loss; left Y-axis)
(source)
you possibly can count on in RG6 cable (by cable size; numerous coloured traces; see proper Y-axis)
by frequency (X-axis) is:

For different cable lengths not listed, pro-rate the worth for another cable size that’s listed.
So for a cable run of 200ft, double the quantity obtained from the graph above for 100ft, and so forth.

Discover that ‘anticipated loss’ adjustments relying upon the frequency (channel) getting used.
It’s because greater frequencies attenuate (lose power) extra shortly than decrease frequencies.

TIP: An excellent tough linear ‘guestimate’ for the 100 ft curve, for any MHz above 100,
is 2.25 dB plus 1/2 dB for each 100 MHz over 100 MHz. The identical formulation, however
reworked for straightforward ‘psychological math’ is to take the MHz, divide by 100 (transfer decimal two locations),
subtract one, divide by 2, and add 2.25.

For instance:
(1) for 200 MHz, assume (2.00-1)/2 + 2.25 = 2.75,
(2) for 600 MHz, assume (6-1)/2 + 2.25 = 4.75,
(3) for 750 MHz, assume 6.5/2 + 2.25 = 5.50.
This reply is for 100′ of cable, so then take the consequence and pro-rate
on your cable distance.

Splitter Loss: The dB loss (between IN and OUT ports) precipitated through the use of a passive
splitter ought to be printed on every output port of the splitter (instance seen proper).
Generally, count on the loss for every output port of a splitter to be ’round’:

Splitter Loss

2-way 3.5 dB

3-way (balanced) 5.5 dB

4-way 7.0 dB

6-way (balanced) 9.0 dB

8-way 10.5 dB

Please word that each one splitters additionally act as ‘combiners’ within the reverse path, with the
similar dB loss between OUT and IN ports. For instance, with a 2-way splitter, count on
3.5 dB loss within the downstream (cable firm to deal with), but additionally count on 3.5 dB
loss within the upstream (home to cable firm).

Additionally word that the cable related to the “IN” port all the time has the sign coming from
the cable firm, and that cables related to the “OUT” ports all the time sends that
(attenuated) sign to different units (STB, cable modem, one other splitter, and so forth).

The historical past of Comcast TECH visits (truly, all appeared to be contractors, not Comcast
staff) attempting to repair the Web downside at my one location in Georgia (that precipitated
this paper to be written) are as follows:

‘That is loopy, why am I paying for unhealthy Web — I
am simply going to maintain reporting the issue to Comcast till they discover and repair the issue’

2020/06/12: The TECH blamed a nasty underground cable run from the
pole to the home (mentioned landscapers will need to have hit the underground cable).
A brief ‘above floor’ cable was run that day, but it surely was changed days later with an underground run
by a special crew. Curiously, as a substitute of the earlier RG6 underground
run to the home, a thicker RG11 (a cable with a barely decrease attenuation) was put in.
The issue remained.
2021/05/19: The TECH blamed a nasty port on the faucet up the phone pole. The home
run was moved to a different port on the faucet. Comcast truly charged me $100 for this go to, which
I lastly acquired refunded.
The issue remained.
2021/05/29: The TECH blamed splitters within the demarc field on the aspect of the home.
Each have been changed. One was a 3-way splitter feeding (1) the modem, (2) the X1 cable field, (3) an
8-way splitter feeding all different one-way cable containers.
The issue remained.
2021/08/18: The TECH proactively changed all F-connectors within the demarc
field on the aspect of the home. A textual content from the TECH mentioned “all that was carried out was new fittings”.
The issue remained.

However see 10/01 beneath — all F-connectors have been put in improperly. Additionally, once I appeared in
the cable demarc field, I discovered that the road feeding your complete home was 100% unfastened — touching
and never even screwed collectively in any respect. The TECH clearly missed placing a connection again
collectively!

2021/09/09: The TECH by no means confirmed up for the appointment.
2021/09/11: The TECH blamed “suckout” and “low mEr” on the faucet
on the phone pole (see picture higher proper).
He submitted a ticket to Comcast to get that fastened. The graphs far above on this paper
present an enchancment in sign ranges. The subsequent day, Web appeared higher and was higher for
weeks (however I additionally put in a lossless amp at the very same time, which improved SNR),
however the issue finally ‘got here again’ in late September.

Oh boy, doing it flawed: Discover the TECH (picture higher proper) hooked the ladder on
the precise cable traces, as a substitute of hooking the ladder (solely inches greater) on the
a lot stronger messenger cable. Additionally the TECH was testing an unused port on the faucet
as a substitute of the port feeding my home.
2021/10/01: The TECH blamed improperly put in F-connectors within the demarc field.
Main issues have been discovered (dielectric not flush) with all F-connectors
on all cables within the demarc field on the aspect of the home, and ALL have been changed. The TECH mentioned
it was so unhealthy that he was stunned that the X1 cable field was even purposeful. We seen a latest
model new downside of ‘blocking’ on TV channels that additionally went away after the F-connectors
have been changed, confirming the impression of the unhealthy F-connectors.
Completely loopy since these F-connectors had been inspected and changed (apparently improperly)
solely weeks earlier by one other TECH on 8/18.
The issue finally remained.

I later discovered a close to brief (uncovered foil) in one of many connectors placed on by
the brand new TECH. Under no circumstances shocking since I watched first-hand because the TECH
used the compression instrument after which did NOT examine the ensuing connection
for defects. If he had, he would have discovered his personal mistake in workmanship.

Overhead Cable Faucet

2021/10/08: The TECH by no means confirmed up for the appointment.

2021/10/09: I spent the following a number of days tracing
cable runs, inspecting ALL connectors in every single place, and changed a number of unhealthy
connectors. See additional beneath for extra particulars.
2021/10/12: FINALLY, a Comcast TECH (worker) got here out (not a contractor), who
mentioned they arrive out when too many contractors are despatched to the identical location and are
unable to repair a problem. The TECH targeted on the phone pole;
discovered that the ariel connection on the faucet was unfastened
(see picture proper);
changed all connectors on the pole for the drop line to the home (one excessive; two low);
examined sign high quality at every step; tightened all connections utilizing a wrench; labored
again to the demarc location; finally ended up on the modem location inside the home;
examined and mentioned every thing appeared good. At first, Web appeared higher, however
the issue remained.
2021/10/31: The native “Technical Operations Supervisor” got here out (I used to be not on the home)
and mentioned that one of many runs in the home was inflicting noise ingress.
A hi-pass ‘filter’
was positioned on that one run — in order that any ingress on this run (inflicting interference
within the frequency vary utilized by the cable modem) could be blocked.

I presume what the Supervisor put in was an “in-line excessive go coupler barrel
adapter 54-1000 MHz filter” (instance seen proper) on the ‘noisy’ run that
had a one-way cable field. The filter
blocks the frequencies beneath 54 MHz (that are utilized by modems and two approach cable
containers). On this approach, the noise ingress from that one run is blocked from impacting
the cable modem add channels.

2021/11/21: The issue went away for a brief time frame, however I used to be
capable of remotely affirm that the issue nonetheless remained!

2022/01/19:
I got here again to the home to seek out that the Supervisor had positioned a ‘lock’
(see arrow in picture proper) on the demarc field, which was a jerk transfer as a result of inside
that field is MY amp, and it prevented me from additional testing alone. I requested
the Supervisor to take away the lock, and he or she agreed (in writing), however nobody ever got here
to unlock the demarc field!

2022/05/29: I lastly purchased the particular $10 instrument on Amazon
that enables me to lock/unlock the demarc field myself. So as soon as once more, I related
the cable modem on to the Comcast demarc location (bypassing ALL home wiring)
and confirmed that the issue nonetheless remained, even with all home wiring disconnected.
I nonetheless skilled common cable modem T3 drop outs. A gathering with the native
Supervisor was scheduled.

tech changing drop cable
2022/06/11: The native “Technical Operations Supervisor” was supposed to come back
out a second time, however as a substitute despatched a daily contractor out, not even a Comcast worker.

The tech arrived to seek out me testing and my modem related on to the Comcast demarc location
(bypassing all home wiring) and nonetheless experiencing important Web drop outs.

I defined a short historical past of the issue and said to the tech that even once I related
my modem to the bottom of the phone pole, I nonetheless skilled issues (eliminating the
underground run from the phone pole to the home demarc location as the issue), and that
this meant that the issue was someplace on the phone pole on up, and I said that I needed
each the TAP ({that a} prior tech mentioned had a nasty port) and drop cable
(the road operating from the TAP to base of the phone pole) changed.

The TECH defined that solely Comcast itself (and never him, a contractor) can exchange the TAP,
however mentioned that he would do the one factor that he might do, which was to
exchange the drop cable.
So this tech:
(a) changed the drop cable from the TAP to the underside of the phone pole,
(b) changed the bottom block on the backside of the phone pole,
(c) changed the connector on the underground run to the home (on the floor block), and
(d) moved the drop cable to a special port on the TAP (to a port that surprisingly a previous tech had mentioned was unhealthy).

I additionally watched this tech incorrectly spin a floor block
onto the tip of the cable, as a substitute of turning the cable onto the tip of the
floor block. Argh!

So, are issues lastly 100% fastened? YES! The variety of essential cable modem errors
is now practically zero. In comparison with earlier than, with a number of essential errors each hour, that could be a enormous enchancment.

The final word core downside at this location was both (1) a nasty RG6 drop cable
(the run from the TAP on the high of the phone pole to the bottom block on the base of the phone pole),
or (2) a nasty floor block on the base of the phone pole.

The F-connectors on the drop cable have been changed quite a few instances over time by numerous
techs — with out serving to — which excludes unhealthy F-connectors as the basis downside.

The underside line: Why did it take years and 10+ tech visits to repair this downside?
It’s clear from all of the tech visits documented above, that what cable techs
do and say is filled with contradictions. It positive looks as if a variety of techs (contractors) know
simply sufficient to generally assist, but additionally have some ‘commerce craft’ / high quality points.

A home subsequent door works simply superb:
As an fascinating aspect word, a second location/house that’s simply 200′ away and on the identical amp
up the phone pole (however on a special leg off of that amp, and a special faucet) by no means
has any of those intermittent Web points.

An extended historical past of issues with Comcast:
In 2005 we signed up for Web from Comcast, however each time it rained, the Web would
drop out for hours (generally even the remainder of the day). Comcast might by no means discover the issue.
Out of desperation, in 2008, we switched to slower DSL, solely to get dependable Web — and it labored! However
in 2017, as a consequence of a lot sooner cable Web speeds, we switched again to Comcast and examined. The
‘rain’ downside was gone. However we seen a brand new very annoying intermittent
cable modem challenge. Through the years, I’ve tried three completely different cable modems (completely different distributors),
they usually ALL skilled the identical intermittent downside.

How one downside was fastened:
After the TECH failed to point out up for the 2021/10/08 appointment, I had
had sufficient and spent the weekend discovering/inspecting ALL cable runs in every single place myself,
and located quite a few issues (however not the ‘core’ downside):

A connector on the floor block on the phone pole for the run to
the home was ‘tight’ however NOT absolutely screwed in. After fixing, cable modem
upstream energy stabilized for a time.
The TECH on 2021/10/01 had changed a ton of connectors, however truly
left with a substitute connector in a just about “shorted out” situation (see picture
proper). The foil was not minimize correctly and wrapped across the dielectric and was a
hair approach from touching the middle conductor.
I inspected ALL connectors behind wall plates in the home and changed
these connectors the place the dielectric was not flush with the bottom of the connector.

The most important classes I discovered:
The variety of tech visits (10+) to this GA location with no decision
was insane. Even the native Comcast
“Technical Operations Supervisor” got here out and didn’t discover the issue!
What I discovered:

Do not assume that there’s only one downside to repair, as a result of in actuality, there’ll
very doubtless be a number of points to repair. And at this location in Georgia,
there have been issues with each the cable firm and with wiring inside the home.
If a few tech visits do not resolve your downside
instantly, insist on a subsequent go to that ALL cables, floor blocks,
and so forth, all the best way from the TAP to your home demarc location, get replaced!
If I had been extra assertive and requested this, my Web issues would have been
solved years in the past.

A BIG clue: Add channel energy high quality / STABILITY is essential:
Cable modem add channel energy ought to stay very constant all through your complete day.
Once you see cable modem upstream energy fluctuate/spike a average quantity
(I used to be seeing 3 to 10 dB) throughout the day, that’s NOT regular, and signifies
an issue to seek out. The doubtless trigger is a nasty cable, someplace, so begin
inspecting cable runs and connectors — in every single place.

Cable TECH’s are making a ton of errors: Even when the TECH who complained
in regards to the high quality of connectors made by a previous TECH, he nonetheless left with a
changed connector in a just about “shorted out” situation.

I even discovered a connection behind a wall plate utterly unfastened (touching, not
screwed collectively), and the final individual to the touch that wall plate was a
Comcast cable tech.

Examine all connectors in every single place: It’s NOT sufficient {that a} connector simply be tight. As an alternative,
take away the connector, examine it (is white dielectric flush with base of connector), and screw it
again on, making certain that the connector screws on about 1/4 inch, and tighten (a robust finger tight).

Throughout this inspection, I discovered (and changed) many connectors behind
wall plates the place the dielectric was nicely above/beneath the bottom of the connector
The unique home builder/electrician did this a few years in the past and was clearly
not very expert!

How one challenge was discovered: I hooked my modem up on to the cable demarc location
along with the home (by way of a 100′ cable) and nonetheless had the intermittent connectivity
downside. That pointed the finger straight on the cable firm.

The connector on the floor block on the backside of the phone pole (crimson arrow in
picture proper) was ‘tight’, however not absolutely screwed onto the bottom submit.

Don’t underestimate the detrimental impression of unfastened (or tight, however not
absolutely screwed in) connectors!

“The primary factor we truly see as a ‘craft error’ is that the connector
is just not correctly tightened onto the port”.
Wealthy Maroney, Product Line Manger Coaxial Cable, PPC.
[Source: YouTube video]

A last phrase:
Most cable modem issues can finally be traced again to ONE challenge: one thing cable
associated (a nasty cable, a nasty connector, and so forth) both inside the home, or within the run
from the cable firm to the home. If you’re prepared to spend some effort and time,
you must be capable to use the method of elimination to seek out the placement of the basis trigger. And when
in-house wiring is in charge, repair the issue yourslef (and when not, name the cable firm to repair).

I’ve carried out my greatest to make this paper as easy-to-understand, no-nonsense, informative
and correct as attainable — in order that YOU can hopefully repair your personal CATV issues.
However it has grown far bigger than initially supposed.
Did you discover an error, a typo, or have a suggestion on how you can enhance this paper?
Did this paper assist you? Do you disagree with any suggestion?
Let me know…

Use this contact form to contact the creator of this paper, Jerry Jongerius.

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