CableConvert
Premium
join:2003-12-05
Atlanta, GA
| [Cable] Could FM Towers be the Problem?
My house is very close to 3 FM towers that broadcast on 96.1, 94.9, and 101.5. If I hook the cable directly to the TV I see ingress on channels 4, 10, and 70. If I go through the cable box, these channels are ok, but I lose a whole slew of channels (33-35, 253...at least those are the ones I wish I could watch). When I pull up the diagnostic page on the Motorola box I am noticing the channels not coming in are in the 600(Hz,MZ...not sure which is right). The last tech that came out said the problem was the local FM towers and I need the house rewired with quad-shield cable. I currently have RG-6. This has been ongoing for a year now since I upgraded to digital. Any advice if I have another tech come out??? |
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MadMANN
Premium
join:2005-08-19
 ·Comcast
| If you are that close to the towers, it could definitely be an issue if the cable isn't shielded correctly and/or the connectors are not installed properly.
Don't forget, those towers are transmitting those FM frequencies, but are also radiating any other frequency in the air. It's basically a big antenna.
I guess my questions are:
1. What is the shielding on your current wiring?
2. Are you sure the connectors are all nice and tight, installed correctly. |
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MacLeech
The one and only
Premium,MVM
join:2001-07-14
SoCal
edit:
April 24th, @10:30PM
| reply to CableConvert
FM frequencies |
The rest of the issues just sound like things caused by low signal, poor wiring, bad splitters, and aren't directly related to the signal output of the towers.
What TV channels do you get with nothing connected to the TV? |
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CableConvert
Premium
join:2003-12-05
Atlanta, GA
| reply to MadMANN
I have checked every connection and even had the tech replace all the splitters. I do not see anything touching the main wire on the connectors. The cable is RG-6U. I checked in the attic and it was running close to the main electrical feed to the breaker box (about 3 feet from it) if that has anything to do with it |
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CableConvert
Premium
join:2003-12-05
Atlanta, GA | reply to MacLeech
with nothing connected to the tv...I get 69, 63,53,46,36,32,30,23,11,05...all those come in to some degree...69,53,36,23 come in fairly clear...the others have lots of snow or distortion but I can tell what they are |
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CableConvert
Premium
join:2003-12-05
Atlanta, GA
| reply to CableConvert
I also noticed that the line going to my modem is spliced. Both ends are screwed together, but I've had no issues with the modem...that I know of.
I have the line coming from the pole to the house...there it splits in to 2 lines. One of those goes to the modem (with splice)...about 50ft. The other line gets split again in the attic. One goes down 1 floor (12 feet max), and the other goes downstairs where it splits for 2 tvs...hope this helps. I have a tech coming Monday and hopefully one way or another this will get solved |
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MadMANN
Premium
join:2005-08-19
·Comcast
| reply to CableConvert
said by CableConvert  :I have checked every connection and even had the tech replace all the splitters. I do not see anything touching the main wire on the connectors. The cable is RG-6U. Ok, you say that you don't see anything touching in the connectors, but are the connectors installed properly and are they decent quality? In other words, is there any of the siver braiding coming out of the back of the connectors at all? Are any of them the slightest bit loose? Believe it or not, those are big factors when it comes in ingress.
Also, there are many types of RG6. Some good, some not so good. I have seen plenty of RG6 that is not shielded well. In fact, I would use a 40' piece of dual shielded aluminum RG59 before I would use a piece of RG6 with nothing but a thin piece of foil around the dielectric.
Last, a splice wouldn't create ingress unless the connectors are not properly installed or the barrel is not shielded properly.
Anyway, with your location and obvious RF-rich environment, there really is no room for error when it comes to your in-house and exterior cable system. |
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CableConvert
Premium
join:2003-12-05
Atlanta, GA
| They all seem to be installed properly. They are tight and none of the shielding is visible. The cable has a thin shield of aluminium then a braided layer on top of that. It certainly wont hurt for me to examine each one more closely. I am interested in why the question about what channels come in with no connection at all...because some of them seem to close to the problem channels |
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MadMANN
Premium
join:2005-08-19
·Comcast
| Ah. Sounds like dual shield cable.
Yeah, a lot of the frequencies that you are having problems with are also in the same spectrum as a lot of OTAs. And the fact that you are receiving some of these without anything connected to the set tells me that these are very strong and could definitely cause a problem where dual shielded cable isn't enough.
My suggestion would be to subscribe to your cable company's guardian plan first so that you don't have to pay through the nose for the service cll. Then have them come back. The repair tech should be able to measure ingress and find out which outlet(s) it is coming from. From there, they can repair service and replace any connectors, cables, or splitters that may be causing the trouble. Now, if your house is pre-wired with cables running through the walls , you may need an electrician depending on your provider's policy regarding wall-fishing.
Good luck. |
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MacLeech
The one and only
Premium,MVM
join:2001-07-14
SoCal
| reply to CableConvert
said by CableConvert :I am interested in why the question about what channels come in with no connection at all...because some of them seem to close to the problem channels With nothing connected to the TV, the shielding within the TV should be enough to block any outside signal from reaching the tuner.
Something in the TV is acting as an antenna or the shielding for the tuner is poor enough for direct pickup to occur across a wide range of channels.
This would interfere with anything being provided to you by the cable company on those same analog channels. |
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CableConvert
Premium
join:2003-12-05
Atlanta, GA | so it could be the TV? Its a small little tv in the kitchen that I tested on...guess I'll disconnect it and see what happens |
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Telcoguru
Premium
join:2005-08-22
Fresh Meadows, NY | reply to CableConvert
You should have told him to hook up some quad-shielded coax to the splitter and run it on the floor temporarily and prove his statement. It might be true but it might not and that would be a big waste of time and money. |
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CableConvert
Premium
join:2003-12-05
Atlanta, GA | They will be here monday...so I believe I will have him do just that! Good suggestion |
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egnlsn
Premium
join:2003-09-26
Salt Lake City, UT
 ·Digis
 ·Vonage
| reply to CableConvert
said by CableConvert :so it could be the TV? I've seen it more than once -- especially on smaller (13") sets. Poorly shielded tuners. Have also seen 26" sets (cable compatible) with no coax connector.
--
CIAO! |
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MadMANN
Premium
join:2005-08-19 | reply to CableConvert
Can't believe I didn't think of the poorly shielded TV. I would definitely back up that notion and check that before rewiring the home. |
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Hayward
K A R - 1 2 0 C
Premium
join:2000-07-13
Key West, FL
edit:
April 30th, @07:01AM
| reply to MacLeech
said by MacLeech :The only channels those FM towers should really affect is is frequencies between 88-108, which is analog channels 95-97. Well if they are that close they are likely seeing spurious harmonics as well which close by can be qute strong, though within FCC specs at X regulation distance.
So a lot of multiples of those frequencies as well.
--
»haywardm.com (Hayward's Key West)
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CableConvert
Premium
join:2003-12-05
Atlanta, GA
| reply to CableConvert
Update...I decided to just rewire the house with RG-6 Quad. I ordered enough to do the whole house got compression fittings (already have the tools for those)...and what happens??? Two nights ago cable tv, internet, all things comcast went down. It was midnight so I figured if it was still down in the AM I'd worry about it. All was well in the morning so I thought nothing of it. Today, I noticed my power levels to my modem had gone from -5 to +3 downstream and my upstream was 37 down from 40...lo and behold, all those channels I wasn't getting come in. I just want to scream because I've been saying that was the problem for over a year. LOW SIGNAL LEVELS!!! I'm still gonna rewire the house, but it just goes to show...ARGH!!!!! |
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MacLeech
The one and only
Premium,MVM
join:2001-07-14
SoCal
| reply to Hayward
said by Hayward :said by MacLeech :The only channels those FM towers should really affect is is frequencies between 88-108, which is analog channels 95-97. Well if they are that close they are likely seeing spurious harmonics as well which close by can be qute strong, though within FCC specs at X regulation distance. So a lot of multiples of those frequencies as well. Harmonics of FM channels should show up as noise on a TV video display, not clear or semi-clear video on other channels to an unconnected TV like the OP is seeing. |
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MacLeech
The one and only
Premium,MVM
join:2001-07-14
SoCal | reply to CableConvert
Good to hear the signal levels improved, but do you still have ingress problems on some channels? |
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CableConvert
Premium
join:2003-12-05
Atlanta, GA
| They must be doing some work on the lines around here. Signal has been all over the place, now US power is up to 47. I'm beginning to think it might be noise in the lines OUTSIDE the house...ingress is back, but the fact that it went away when signal was higher makes me think its not an 'internal' problem like I was lead to believe |
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