[mythtv-users] Which Signal Strength/Quality Alternative is best?

[Gary Buhrmaster]

To list membership.  This is starting to get very specific
to a unique case.  If there is any general consensus
this should be taken offline, I am willing to move this
offline.  Any opinions?



Ok, another long post.....

On Sat, Jan 21, 2017 at 6:12 PM, Craig Huff <huffcslists at gmail.com> wrote:
>
>     Yes, I get my internet from Comcast, but I wouldn't call it high speed,
> unless compared to the DSL I used to have -- dumped that when I had to
> reconnect my modem to get a faster data rate!

Any chance you can provide the signal levels from your
cable modem, and the event logs?  Those numbers
show various error counters, signal levels, and events
that can suggest whether the real fix is to get Comcast
to address a bad drop/source (GIGO, and if the GI
is from the Comcast drop, there is nothing we do
can do really fix it).

*WARNING* do not post the entire MAC addresses
in the logs (it is possible to cause difficulties for others
with others MAC addresses).  Replace the MAC addresses
with X's (if text cut/paste) or use your favorite image
manipulation program to white them out.

Direct email is acceptable if you prefer (but I would
not trust me with my own info, so the same warning
might be appropriate).

>     Yeah, the demark test would be a hassle.
>     As for a description of the connection, it starts with Comcast's
> cheapest cable buried from distribution post at the back corner of my lot
> along the fence line to the side of the house. As I recall, there are at
> least two splices in that line because I cut it while mowing when they took
> 9 months to bury it (then sent a guy out with a shovel and a barrel
> connector -- not even electrical tape)

Ok, a direct burial a repair requires a special
"splice kit" which encases the repair inside
a water sealed "goop" that protects the cable
and connector from water ingress.  And direct
burial cable must be a "flooded" style.  If it is
not, and/or was not properly repaired, you may
have water in the cable/connectors.

Water ingress into coax cable generates standing
waves.  There is no fix other than replace the cable.

The results from the modem signal levels might
hint at this (typically you see the signal levels
all over the place, low, high, low, high, etc) as
the frequencies change.

> and the second is because they cut it
> below the service entrance box rather than knock on the door to say the
> police department reported RF interference in the area and try to fix it.

RF egress/ingress is a common problem with bad
inside wiring.  It causes problems for you, and for
everyone.  Typically Comcast disconnects you
at the street or the demark, but they do what
they have to do (there are typically at least two
different groups involved, the gals/guys in the
truck looking for RF egress, and then the gals/guys
who contact and deal with the customer; unless
the issue is sever, the first ones typically just
"tag" the house, saying "Call us NOW.  NOW,
NOW", but that tag can also get lost).

>     In the SE box is a splitter to separate the Internet and video feeds.

Comcast supplied splitter, or one of your own?

> The video enters at the top of the basement wall and runs about 10 feet to
> where all my connections/distribution HW are. Most TV connections are
> abandoned and unused ports on distribution amp (combo "low noise" amp and
> 1:4 splitter) were terminated with F-connector terminators (probably from
> Radio Shack, too).

Brand/Model?  And is this one of those devices that
use power supply that is multiple years old?  Even
the best amp which is being fed by a power supply
with high ripple (due to bad caps inside the supply)
generates random noise.

> ...  reaches the combination
> surge arrestor/outlet strip. (It has surge arrestor options for RJ-11,
> RJ-15, F-connectors, besides protecting the 120VAC.)

Remove that from the path with prejudice.  I have never
seen a combo device that was not more problem than it
is worth.  If you live in a location which is vulnerable
to lightning,  and do not trust the Comcast provided
bonding point(*), you can consider adding after theirs
a proper lightning protector near the demark with
proper bonding to the house, something like:
   https://smile.amazon.com/TII-Broadband-Cable-Lightning-Protector/dp/B0016AIYU6/ref=sr_1_1?ie=UTF8&qid=1485048795&sr=8-1&keywords=coax+lightning+protection

> A short drop cable from
> there connects to the Ceton box. Cable jackets mostly just say CATV, except
> the one to the Ceton, which is RG-59/U.

Short lengths of high quality RG-59 is not a
problem.  50 meters, yes.

>     I should add that the video problems appeared on the tv connected to the
> Comcast settop box, too.

Admittedly, complaining about a "bad" picture when
using a Comcast STB has the best likelyhood of
Comcast addressing the problem.




(*) In all recent installs Comcast will provide a
bonding block(**) (aka "grounding" block), usually
outside near their demark box.  Older installs
may not have one.  Typically you can request
Comcast install one, and they will do so at no
charge, but no guarantee  about the no charge
part (some states mandate the install for new
installs, and will require Comcast/Verizon/etc.
do it for free; I do not know about your location).


(**) As an EE would know, there is a difference
between bonding to the household bonding point,
and a true "ground".