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HunterZ

join:2003-07-16
Kent, WA

[Signals] Just moved and need some advice

1) Location: Kent, WA (unincorporated King County, a few miles south of Covington).
2) Problem: Low downstream power levels and inconsistent up/down speeds (see below).
3) Reproducibility: Unknown at this time (just moved).
4) Modem stats: Motorola SB6120 v3.0 with firmware SB612X-1.0.3.3-SCM00-NOSH / PSPU-Boot 1.0.0.4m1 / Aug 12 2010 13:58:19.
5) Network: SB6120 -> Asus RT-N16 (Toastman Tomato) -> laptop (via wifi, speed 144/65 and 4-5 signal bars out of 5).
6) Firewall/anti-virus: Vista firewall is disabled, anti-virus is MSE 4.0.1526.0.

Tier: 20mbps "Blast!" Not sure what advertised upstream is. Can't check bill due to Comcast site issues (as usual).

Browser: Firefox v13.0.

Detailed discussion:

So I just moved from Kent East Hill (south of Renton) in Washington to a few miles south of Covington. This is technically more "out in the sticks", but the development my new house is in was built in the early 1990s (whereas my old house was built in 1978 or so).

I have Comcast's 20mbit Blast! service and a personally-owned SB6120 cable modem. At my old house, I could get as high as 20/4 (mbps up/down).

At my new house, there was a +15db cable amplifier already installed in the garage. I initially tried bypassing it (replaced it with a female-to-female coax connector) as well as the 3-way splitter on the outside of the house. Unfortunately, this resulted in downstream power levels of around -11 to -12 dBmV. I put the amp back in the loop and am now getting around +4 dBmV (as expected).

At first I was getting a single upstream channel, but now I am getting 2 again (like at my old house) with power levels of 42-44 dBmV. I believe this is actually slightly better than my old house, which I believe usually hovered around 45-47.

The amplifier thing wouldn't bother me at all, except that my speeds seem to be all over the map. I did remember to disable QoS on my router (Asus RT-N16 with Toastman TomatoUSB) and I did do a "Reset All Defaults" on the SB6120 cable modem to make it tune to the new connection (although I did do this before I "activated" the connection since Comcast's self-activation page wasn't taking my account number, but I wouldn't think activation status would matter since I was getting a signal and connection to the walled garden?).

Specifically, I started out getting reliable 20mbps download, with upload anywhere from 0-2mbps (this was with speed tests; I never had any noticeable connection or packet loss). After we left for dinner and came back, I now seem to be getting 7-18mbps down and 2-4mbps up.

Questions:
- Is the amp something I need to worry about?
- Is there something Comcast can/should do at their end to address the -12 dBmV downstream power levels?
- Any idea why my speeds would be so inconsistent?
- Is it possible that the SB6120 is still tuning to the connection after 9 hours (and ~3 hours after full activation)?


tshirt
Premium,MVM
join:2004-07-11
Snohomish, WA
kudos:5
Reviews:
·Comcast
Yes having a Amp on the cable line is a bad idea, even a really good amp (like comcast would install as a last effort)would introduce some noise, and might intfere with the return signal

Yes Comcast should be able to fix it

Probably noise/problems maintaining sync

channel changes can happen any time, and signal constantly fluctuate somewhat, if yours is going beyond normal or the amp is injecting noise you may have huge numbers of resends or other problems
If you posted the log we might see some indications of what but I thing you need a tech visit to get even close to good.

rody_44
Premium
join:2004-02-20
Quakertown, PA
reply to HunterZ
Any chance you can put the modem where the amp is and get the levels there. That way we will probably know if the problem is inside the house or out on comcasts end.


HunterZ

join:2003-07-16
Kent, WA

1 edit
reply to tshirt
said by tshirt:

If you posted the log we might see some indications of what but I thing you need a tech visit to get even close to good.

Comcast's SB6120 firmware seems to disable/redirect most of the useful logging. All I have are some old, useless boot-up messages:
Jan 01 1970 00:00:18 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=3c:75:4a:75:5c:f7;CMTS-MAC=00:1d:70:cc:4e:3e;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:12 6-Notice Cable Modem Reboot from SNMP ;CM-MAC=3c:75:4a:75:5c:f7;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:18 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=3c:75:4a:75:5c:f7;CMTS-MAC=00:1d:70:cc:4e:3e;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:12 6-Notice Cable Modem Reboot due to power reset ;CM-MAC=3c:75:4a:75:5c:f7;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:18 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=3c:75:4a:75:5c:f7;CMTS-MAC=00:1d:70:cc:4e:3e;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:12 6-Notice Cable Modem Reboot due to power reset ;CM-MAC=3c:75:4a:75:5c:f7;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:22 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=3c:75:4a:75:5c:f7;CMTS-MAC=00:1d:70:cc:4e:3e;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:12 6-Notice Cable Modem Reboot due to power reset ;CM-MAC=3c:75:4a:75:5c:f7;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0;


said by rody_44:

Any chance you can put the modem where the amp is and get the levels there. That way we will probably know if the problem is inside the house or out on comcasts end.

Well crap! I'm glad you suggested that, because that gives me -4 to -5 dBmV down (with 36-37 dB SNR) and 40 dBmV up. Running speed tests, I am getting 14-15mbps down (ouch, what happened there?) and consistently over 5.5mbps up (wow!).

Previous owners of the house must have either used some low-quality cable in the mere 20-30 foot run to the family room, or else there's a second hidden splitter along the way besides the one I bypassed outside the garage. I'll take a look and see if I can trace the line. Unfortunately I think it may run inside of the shared wall between the garage and family room, then through a hole in a full-wall built-in entertainment center / shelving system (EDIT: Actually it probably runs under the crawlspace or something, likely with a female-to-female extender or splitter somewhere since the cable looks completely different on the side of the house versus the family room).

The downstream power level is still a bit low even when connected directly, though, especially since I do need to add a 2-way -1.5dB splitter to get both TV and Internet service. I expect that this would result in -5 to -7 dBmV; is that still a worrisome number? I would not want to use the amplifier in that configuration, as I've heard that the SB6120 doesn't like +10dBmV or higher.

I'll try to take some pics with my phone once it has charged up a bit. For now, here is a pic I took of the amp in the garage in case anyone is interested: »docs.google.com/open?id=0BwvZzVl···RSFFuQzQ


plencnerb
Premium
join:2000-09-25
Carpentersville, IL
kudos:3
I take it the line that is in your garage is the "main" line into your house? You don't specifically say that, but by what you said, I think my guess is true.

I would see if there is a way to trace your line, as it does appear to either be added splitters going in, or maybe even some loose-fitting connections. It could also be (as you said) bad coax too.

Finally, when I went to look at the picture you linked of your amp in the garage, I don't get a picture, but a video and an ad page for Google Drive. Am I missing something?

--Brian
--
============================
--Brian Plencner

E-Mail: CoasterBrian72Cancer@gmail.com
Note: Kill Cancer to Reply via e-mail


ropeguru
Premium
join:2001-01-25
Mechanicsville, VA
Click for full size
Worked fine for me. Here is the pic.


HunterZ

join:2003-07-16
Kent, WA

1 edit
reply to plencnerb
said by plencnerb:

I take it the line that is in your garage is the "main" line into your house? You don't specifically say that, but by what you said, I think my guess is true.

So the main line from Comcast comes out of the ground outside of the garage, and has what appears to be a foam cylinder around part of it that says "AMP" (must be a brand name since it's not related to the amplifier). This wire goes into a hole in the side of the house that leads straight to the garage.

In the garage above the hole, that cable enters the top right of the amplifier. The top left is the power input from the wall wart, and the bottom is the amplified output.

The amplified output cable goes back out the same hole to the outside, and originally went into a 3-way splitter mounted to the outside of the house. I bypassed this with a GE/Jasco female-to-female coax connector (aka "double F jack") so that only the cable to the family room was connected.

The family room, office and 1 undetermined cable go back into the same hole in the side of the house, but instead of going into the garage they disappear completely. I suspect they go down into the crawl space. All cables are black (as far as I can tell, since they got covered in tan house paint at some point) and have F connectors on the ends outside the house that appear to have been installed by Comcast at some point. Inside the house, all of the F connectors are a different style; I will try to post pictures later when I get a chance.

In the family room, about 10-15 feet of white coax comes out of a hole in the wall (yes, white, even though outside the house the corresponding cable is black). I can see yellow insulation in the hole. I tried tugging on the white coax cable, but it seems quite secure inside the wall.

said by plencnerb:

I would see if there is a way to trace your line, as it does appear to either be added splitters going in, or maybe even some loose-fitting connections. It could also be (as you said) bad coax too.

I'm not keen on spelunking my crawlspace. Anyone know how much Comcast might charge to run 25-30 feet of high-quality cable across a crawlspace between two pre-cut holes?

In other news, I moved the cable modem back to the family room, re-activated the amplifier, and hooked up a Comcast-supplied 2-way splitter in the family room so that I could also connect the TV. The cable modem is now showing exactly 0 dBmV on all 4 downstream channels, plus 46 dBmV upstream. I suspect that previous residents installed the amplifier (or had Comcast install it) and worked with Comcast to tune the connection without knowing that the house wiring has problems.

Edit: Here are some more pics:
- Cable situation outside of the wall that the amplifier is on (blue tape is my attempt to label that cables): »docs.google.com/open?id=0BwvZzVl···WVmNuYWM
- Temporarily bypassing the amplifier with a GE/Jasco "double F jack": »docs.google.com/open?id=0BwvZzVl···rTzZudUU
- Family room cable, to which I have connected to a Comcast-supplied 2-way -1.5 dB splitter for the Internet and TV service: »docs.google.com/open?id=0BwvZzVl···1OC1CQjA
- Family room cable coming from hole in wall/built-in cabinet: »docs.google.com/open?id=0BwvZzVl···tenRTcXc


HunterZ

join:2003-07-16
Kent, WA

1 edit
Update: With cable -> amp -> family room -> 2-way splitter -> modem and TV, I am consistently getting around 20 mbps down and 5+ mbps up. This is as good of performance as I was getting when connected directly to the line in the garage. I guess being able to bond 4 channels down and 2 up is enough to make up for needing the amplifier to reach 0 dBmV (which is exactly where the downstream power level is at).

I think I'm going to live with the connection as-is for now, since I don't expect to be able to get better performance from correcting it. I will continue to monitor stability and speed, though.


ropeguru
Premium
join:2001-01-25
Mechanicsville, VA
What you really need to do is get a truck roll and have Comcast come out and get the ball rolling to get the levels adjusted without the AMP.


HunterZ

join:2003-07-16
Kent, WA
Is it normal for house wiring to cause a -8 dBmV drop? Since I'm getting -4 dBmV at the line from Comcast, I'm concerned that they're going to blow me off by saying that that is good enough and that the house wiring is my problem.

rody_44
Premium
join:2004-02-20
Quakertown, PA
Reviews:
·Comcast

1 edit
No -4 isnt normal. But we still dont know the actual signal. I believe that thing marked Amp is nothing but a splice connector. Open that up and that is where the actual comcast signal would be. Thats if im reading the picture correctly. Its not out of the question that a piece of bad coax only a few feet long loses 15 dbs. Even the piece as short as the one going from outside to iinside your garage. The piece at the outside is what is important in comcasts eyes.

rody_44
Premium
join:2004-02-20
Quakertown, PA
Reviews:
·Comcast

1 edit
reply to HunterZ
The cable both in your family room and at the amp in the garage look to me like some premade cables you buy at a home improvement store judging by the ends. All the cables outside have ends that would be typical of cable company installed cables. So im guessing all your cables are homeowner installed and the cable company simply put ends on the ones outside. I dont see your cable bonded at all. Not good, especially with a modem.


HunterZ

join:2003-07-16
Kent, WA
said by rody_44:

I believe that thing marked Amp is nothing but a splice connector. Open that up and that is where the actual comcast signal would be.

I'll try to do that when I get a chance. I did take a closer look and found that it is actually a hard plastic case that may not be easy to open, as it appears to snap together with tabs. It doesn't look like opening it will be as trivial as I'd hope.

said by rody_44:

Its not out of the question that a piece of bad coax only a few feet long loses 15 dbs. Even the piece as short as the one going from outside to iinside your garage. The piece at the outside is what is important in comcasts eyes.

As I mentioned before, I get power levels of -4 dBmV just inside the garage, so I'm likely not losing more than 4 dB in the couple of feet between the splice and the inside of the garage. I definitely want to check what signal levels I can get at the splice, though.

said by rody_44:

So im guessing all your cables are homeowner installed and the cable company simply put ends on the ones outside.

This was my guess as well; it's good to get confirmation.

said by rody_44:

I dont see your cable bonded at all. Not good, especially with a modem.

I would have expected at least the splitter to be grounded, but it isn't. The "Amp" case is lashed to the telephone conduit with a plastic zip-tie, and is not electrically connected to the conduit or anything else as far as I can tell.

My house electrical mains come from underground, and connect to the meter box via a conduit. I'm a bit uncertain about where I can get an optimal ground connection from, although I see a few possibilities (also refer to pictures below):

1. A copper wire (I think; it's covered in stupid house paint too) with green plastic shielding/insulation that appears to come out of the ground and is not connected to anything on the end I can see. It looks like this could be it; since I don't want to use an exterior coax splitter, should I instead purchase and install a coax ground block between the splice point and attach the green wire to it? Can I verify that the green wire is grounded by touching an ohmmeter to it and to, say, my electrical mains conduit or what I think may be the ground rod?

2. A twisted steel cable of the type I've often seen attached to ground rods with a clamp/electrode. It comes from the ground near the green wire and immediately disappears up under the siding. I suspect this may run to the breaker box in the garage or something.

3. A metal rod (possibly zinc or steel, although it looks a bit rusted on the very top) protruding just a couple inches from the ground, with no electrode/clamp attached. Could this be the ground rod, with everything connecting underground? It does look like the green wire and twisted steel cable come out of the ground just a few inches away, on the house side of the rod.

4. The natural gas meter conduit on the opposite end of the wall has some wires attached to it that come out of the ground right next to it.

Here are some more pictures in case they help:
- Closeup of possible ground connections: »docs.google.com/open?id=0BwvZzVl···obWZuUGM - note the twisted steel cable near the top left, green wire near top middle, and rod at lower left
- Wider shot of electrical/cable/telephone area: »docs.google.com/open?id=0BwvZzVl···ETGg4eVk - large conduit on left is electrical mains (with meter at the top), small conduit next to it goes to an RV power outlet, and rightmost conduit goes to telephone connection box. Cable comes from underground near the telephone conduit, and splice box is lashed to the same conduit.
- Even wider shot of the above, showing the electrical meter: »docs.google.com/open?id=0BwvZzVl···UZ1REVTQ
- Even wider shot of west side of house, with gas meter on right and electrical/cable/telephone on left: »docs.google.com/open?id=0BwvZzVl···YZFpvTnM


retiredqwest

join:2005-04-01
Spokane, WA
quote:
1. A copper wire (I think; it's covered in stupid house paint too) with green plastic shielding/insulation that appears to come out of the ground and is not connected to anything on the end I can see. It looks like this could be it; since I don't want to use an exterior coax splitter, should I instead purchase and install a coax ground block between the splice point and attach the green wire to it? Can I verify that the green wire is grounded by touching an ohmmeter to it and to, say, my electrical mains conduit or what I think may be the ground rod?

That is probably the ground wire that may have been attached to the coax ground block. Telco and CATV use a #6 wire w/green insulation for that purpose.

Using a Multimeter, set it on AC Voltage FIRST and test the wire. Then test it using the ohms scale.

quote:
2. A twisted steel cable of the type I've often seen attached to ground rods with a clamp/electrode. It comes from the ground near the green wire and immediately disappears up under the siding. I suspect this may run to the breaker box in the garage or something.

That is probably the power ground to the breaker panel.

quote:
3. A metal rod (possibly zinc or steel, although it looks a bit rusted on the very top) protruding just a couple inches from the ground, with no electrode/clamp attached. Could this be the ground rod, with everything connecting underground? It does look like the green wire and twisted steel cable come out of the ground just a few inches away, on the house side of the rod.
That is a 6-8' ground rod, if you dig down there should be 3 connections attached to it. CATV, Power, and Telco attach to it to make a 'common' ground.

quote:
4. The natural gas meter conduit on the opposite end of the wall has some wires attached to it that come out of the ground right next to it.

Those are used to attach a cable locator, since the pipe below the ground is plastic to the street.

IMO, you should make Comcast come out and fix that mess. You really shouldn't have to fix things and legally they are responsible to make sure that the coax has adequate grounding at your premises.

You may also want to consider rewiring the entire house. Ya, I saw you mentioned a crawl space..... If you wire the house and do what we call a 'home run' with each outlet you could probably eliminate most of the splitters you have now and maybe even the AMP. It all depends if you have the time and how long you think you are going to stay in that house if you want to make the effort.


HunterZ

join:2003-07-16
Kent, WA
Thanks, I'll contact Comcast about having a grounding block installed on the tap.

I'm not a huge fan of crawlspaces (especially ones that previously had mice in them), but I think I should really run a new 25-30 foot cable from the outside of the house down into the crawlspace and over to the family room. Are there any good options for having someone else do this without paying an arm and a leg?

I also really don't want to re-wire the whole house at this time; I just want to have both the TV and Internet service in the family room (I already have wifi and HomePlug AV equipment to distribute the LAN/WAN throughout the house), and we currently have no plans to use TVs anywhere else in the house.


retiredqwest

join:2005-04-01
Spokane, WA
I think you might be hard pressed to find someone willing to do the crawlspace thing on the cheap. Especially concerning mice and Hanta Virus.

The Comcast tech will more than likely not be interested in doing it either... but it won't hurt to ask how much to install the line.

He might be willing to provide the RG6 cable for free. So, if you get the cable placed they will come back and install the connectors for free.

Is it possible to get close enough to the family room on the outside of the house?

On Craigslist, there's some guy in Kirkland who will install coax for a $1 a foot....8)


HunterZ

join:2003-07-16
Kent, WA

1 edit
I'm actually a bit confused about where the current line to the family room is installed; it goes into a hole in the garage wall and then disappears, but my understanding is that it's not likely that there is crawlspace under the concrete-floored 3-car garage. I think there's a vent in the foundation on that side of the house, though, so I guess there must be a space under it?

Going around the outside wouldn't work too well, but I have been thinking of an alternative: the built-in entertainment center shares a wall with the garage, so I could drill into the garage by going right through the back of the existing cable hole. I could then tack up RG6 around the garage to where the existing cable comes in. This would involve going over a door and behind the tankless water heater and furnace, but I don't think any of that would be too dicey.


HunterZ

join:2003-07-16
Kent, WA
reply to HunterZ
Updates:

Measured how much cable I'd need in order to run it through the garage; I think I'd need around 60 feet.

Called Comcast to ask about some HD TV channels appearing to be out of service, but it turned out to be my fault for not realizing that I had used a short run of RG-59 to connect the Tivo HD to the 2-way splitter (doh!). Didn't realize that a symptom could be specific channels dropping out while adjacent channels still work fine. Jiggling the cable made them work, but I replaced it with an RG-6 cable with better looking connectors (although it was unfortunately also longer) and the signal on those channels appears to be quite solid now.

While on the phone with Comcast, I also asked about getting a ground block installed at the drop. They put in a request to have someone call me in 4-7 days to schedule a technician visit.


wa2ibm
Premium
join:2000-10-10
San Jose, CA
Running a new coax from the living room inside the garage is a good idea. However, since the wall is between living space and the garage, it's most likely a firewall (a real fire wall, not a network one). Any hole(s) you poke through that will have to be resealed in a fireproof manner. You'll probably find there's a layer of plywood under the rock on the garage side.

Is there power nearby in the garage where that amp is located? Might I suggest that you hang the SB6120 on the wall next to the amp and run a section of CAT5 along with the coax back to the living room and your router. That way, any splitter installed when Comcast comes to visit will be near your service entrance, and any loses to the modem will be minimized.
--
- Bill


IowaCowboy
Iowa native
Premium
join:2010-10-16
Springfield, MA
kudos:1
Reviews:
·Verizon Broadban..
·Comcast
reply to HunterZ
The tech that did the install (move in installs always require a tech as they have physically connect the house drop to the tap) should have checked the signal levels. They are also supposed to check for leakage when they do an install.

Sounds like a truck roll is needed.

Also the rural nature of your area could explain the weak signals as distance from the node/amps may be greater.


HunterZ

join:2003-07-16
Kent, WA

1 edit
said by wa2ibm:

However, since the wall is between living space and the garage, it's most likely a firewall (a real fire wall, not a network one). Any hole(s) you poke through that will have to be resealed in a fireproof manner.

That thought did occur to me, and I was wondering what I should do about it. It looks like at minimum I should use some fire-resistant caulking/seal, but should I be using some kind of conduit and/or box as well?

If anyone could provide links to specific examples hardware/materials that I ought to consider, it would be much appreciated! I'm not much of a DIYer, but I hope to enlist my wife's help as she worked in and taught university level theatre stage management, lighting and sound design

said by wa2ibm:

Might I suggest that you hang the SB6120 on the wall next to the amp and run a section of CAT5 along with the coax back to the living room and your router. That way, any splitter installed when Comcast comes to visit will be near your service entrance, and any loses to the modem will be minimized.

That's a really good idea, thanks! I'm thinking I'd connect from the drop to a 2-way splitter inside the garage, then do a short coax run (5 feet at most) from the splitter to the modem.

I'd then run ethernet from the modem to the family room to reach the router, and I would also run coax from the second leg of the splitter to the TV. This means I'd need to be able to feed both coax and ethernet through the firewall between the garage and the family room.

said by IowaCowboy:

The tech that did the install (move in installs always require a tech as they have physically connect the house drop to the tap) should have checked the signal levels. They are also supposed to check for leakage when they do an install.

There was no tech at the house. Comcast gave us the option of doing a "self install" instead of rolling a truck. Since I wanted to get the Internet up ASAP, I chose the former option. This turned out to be a potential mistake because Comcast's walled garden activation wouldn't work for me and I had to do it over the phone instead. The TV activation was similarly involved, except that I also wasted an hour on Comcast's online chat system just to find out that I still needed to call a phone number.

said by IowaCowboy:

Sounds like a truck roll is needed.

I've made an appointment to make an appointment (seriously) to have a truck roll in order to get a grounding block installed. I plan to talk to the technician about some of the other issues and hopefully bum some RG-6 with good connectors on it.

said by IowaCowboy:

Also the rural nature of your area could explain the weak signals as distance from the node/amps may be greater.

I think it's mostly the house wiring, which seems to be costing me at least 8 dBmV of signal loss between the entry to the house and the family room.

As I mentioned before, I can't yet test right at the drop due to a plastic cylindrical box that is likely covering the splice point from the drop to the house wiring, but I get decent power levels of -4 dBmV just after that. Hopefully Comcast can boost the power by at least 4 dB at the tap (so I get at least 0 dB at the drop) once I get my new house wiring installed.

-----
Edit/Update: After finding that example of RG-59 that I had accidentally/desperately used on the TV, I checked the house wiring outside the garage and found that it, too, appears to be RG-59 (I can easily bend the center conductor with my finger). This probably explains why I'm losing 8 dB of signal between the garage near the drop and the modem in the family room.

As I mentioned before, the cable to the family room on the outside of the garage is black, but the family room end is white. It appears that the family room end is RG-6. I wish I knew where they joined them and how the cables are run. It appears that there is probably no crawlspace under the garage (double-checked and saw no crawlspace vents around the garage), so I have no idea at all how the cable runs inside the walls/attic/crawlspace/whatever nor where the black RG-59 and white RG-6 are joined.


HunterZ

join:2003-07-16
Kent, WA

1 edit
reply to HunterZ
So my wife got a voicemail from Comcast saying that they were going to come out "some time in the next couple days" to look at the grounding/bonding situation.

This is disappointing because I wanted to talk with the tech about things like the splice box (if that's what it is) and whether the house wiring at the drop is actually RG-59 (as it appears to be).

I also want to make sure that they don't just hook the ground wire up to the 3-way splitter on the side of the house, because I don't want to waste signal by using a 3-way splitter to service 2 devices (modem and TV).

Should I do any of the following, and/or anything else?
- try to call Comcast and hope that I can somehow get the message through to the right people?
- tack a note to the side of the house?
- remove the 3-way splitter from the side of the house? (the house wiring would still be hanging out there, though)

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Update: I happened to be home when the tech stopped by today to install the ground block, which was good for him because he wanted to look in the garage to make sure that it wasn't grounded in there. It was even better for me, as I was able to get a ton of questions answered.

First, the splice box is there because the drop is RG-11. He said that the poles/peds are pretty far apart in my neighborhood because of how far out it is from civilization (IowaCowboy was correct after all - sorry for dismissing your comment!), so both the RG-11 drop and also the amplifier are in fact necessary to get good signal levels. He also said that the house wiring did appear to be RG-6 (even though I had an easy time bending the center conductor).

The tech installed the ground block (looks good, with rubber covers over the coax connections and a warning tag added to the ground line) and checked signal levels at the drop and in the family room, and said that things looked good to him (I don't remember the actual numbers). He mentioned that I could add one more splitter for TV at some point if I wanted, but that using any more splitters with the modem (including just the 3-way splitter outside the house) could push the upstream modem power level out of spec; this is not a surprise since I'm reading 46dBmV from the SB6120 with just the single 2-way splitter.

It looks like he also reconnected the 2 unused house cables to the 3-way splitter, but did not actually route any signal to it. That was probably a good idea, both because it looks nicer and because it will protect the connectors from corrosion or other water damage.

I guess this means I don't need to worry about re-running cable, since I'm getting decent service quality and it probably still won't buy me enough signal to pull the amp out of the chain anyways. I'm not sure why I was originally seeing -4 dBmV downstream before the amplifier near the drop, though...