How does cable box interfere with electronics?

Mr. Sharpe

So I recently got basic cable combo with my internet, at one time I had it sitting on my amp and it made it made the amp buzz really bad. Now it's sitting outside the cabinet and is still causing not as bad buzzing, but it's quite audible. I can unplug the coax cable and it goes away.... But I can't leave it near any of my electronics!!! It interferes with them that bad. HELP. Is there a way to shield it some how?

Moose68Bash

It doesn't sound like it is because the cable box is near your electronics. It sounds like there is a ground loop between the cable box and your amp or other sound system electronics. If so, I don't think shielding will solve the problem.

How is your cable box connected to your TV, and is your TV connected to your preamp/amp?

I had to connect my TV to my preamp with an optical connection to eliminate a hum in my sound system.

There are much wiser guys on this Forum who can give you much better advice then I, but you might start with the above suggestions for diagnosing the problem.

izafar

Looks like a ground loop problem. I recently had the same issue when I added Parasound P5 preamp in the mix. The problem was solved by running the cable signal through the Monster power conditioner.

Toolfan66

Power conditioner..........

[Deleted User]

Mind expanding. I have my furman on backorder...

pitdogg2

Careful with power conditioner as most will drop signal by 2-3db which creates another problem. 90% of the time it's a ground problem with coax cable itself.

classic carl

I was told by a cable tech not to run the cable TV coax thru my power conditioner. I had hum bars on my TV when I first bought it. No audible hum, but green and purple horizontal lines that moved vertically up the TV screen.

I tried running the coax cable thru the power conditioner. That did not help. I had the DVR cable box and DVD player connected to my AVR with component video cables, and then from the AVR to the TV with component video cables. The audio from the cable box and DVD player is connected by optical cables to the AVR. My AVR is older and does not have HDMI jacks.

I then tried connecting the cable box directly to the TV with component video cables and had only the audio running thru the AVR. That didn't solve the issue either. I then connected the cable box to the TV with a HDMI cable and the issue was solved immediately. The audio is still connected to the AVR but not the video. The coaxial cable is only connected from the wall to the cable box. I don't have to turn the AVR on to watch TV without sound. I watch sports on TV with music on most of the time. My music system is separate from my HT system.

We need to know how you have the cable box connected before we can attempt to solve your problem.

Mr. Sharpe

from the wall to the TV, coax cable only.... I did notice this box has different connections but just haven't gotten around to seeing what's back there. I will have to troubleshoot later on.

tonyb

Mr. Sharpe wrote: »

from the wall to the TV, coax cable only.... I did notice this box has different connections but just haven't gotten around to seeing what's back there. I will have to troubleshoot later on.

That's part of the problem, use an HDMI cable whenever possible going to the tv. If you have to use a coax cable, the el cheapos won't do much for reducing noise or hum. Use a good quality cable.

My cable box has HDMI and coax connections. It's also a HD box, so I run HDMI to the TV and coax to the receiver. That way I don't have to have the stereo on all the time to watch tv.

Mr. Sharpe

It has component out and an hdmi out. Will try either one later.

I noticed the other day disconnecting the cable in stopped the noise.

steveinaz

If your cable box has a Toslink out, use that for audio--it will break the ground loop.

Speedskater

Which coax cable do you unplug, the one from the wall to the STB or the one from the box to the TV?

Mr. Sharpe

the one from the wall but that was the previous box, haven't gotten around to messing with it.

Mr. Sharpe

using an HDMI cable solved the problem:) all is well. I noticed also before changing that one of the speakers wasn't playing correctly, like reduced volume from other channel and no highs, not it's working correctly.

I'm using Klipsch RB-61's and let me say I'd recommend them to anyone for any use. Unless of course you have a larger room get Polk RTA 12's

mantis

I see you resolved your issue but I would also do the following.
Call the cable company and have them reground your outside connection. This is where the issue is. You may have masked it but it's still there. If you have the ground fixed, the issue will be truly gone.

When you have a surge protector with cable protection, this works on all analog cable systems but don't on Digital like Verizon Fios. Verizon sends a pure digital signal and sending into a surge even if it did work will yield no benefits. With Verizon they send the signal to your house over fiber. This doesn't cause any grounding issues like Coax cable does. There is no polarity.
With Analog signals , running the coax into a surge protector that is designed for todays cable systems can lift the grounding issue and protect from a surge spike which is a common issue in the north where Electrical storms are very common.
I deal with this at least once a week. I have seen so many systems taken out by electrical storms even with a high quality surge because the surge came over the coax cable and everything metallic connected gets a jolt. Sucks but it is what it is.

Where your cable system d mark or head end or whatever you want to call all points landed is another area where you can put a proper ground. The Proper way to distribute cable around ones home is have a central point so all cable feeds go to one place and don't have any splitters anywhere except in one place. So the main feed comes into the house and then a splitter divides up all the runs to all the rooms that require cable service. So if you have 7 rooms you need a 8 way splitter.
At this location , you can ground that splitter with grounding wire to a copper pipe with a Copper pipe clamp. This will also stop the madness of grounding issues. The outside ground is a much better way to get this done but if thats not possible in one way or another , this is the alternative way to get it done.

Mr. Sharpe

Sounds good, I'll get them to do that, I have to call them back anyway because I'm only getting 13 channels when I'm supposed to get something like 40.... I know I know, you've heard of basic cable right? this is ubasic cable:) (uber basic)

steveinaz

You can have the cable co check your ground, I checked and improved mine; but it didn't help. The problem lies with different ground voltage potential between the house power outlets and the grounding system of the cable run. It's a real pain, but it looks like you found a work-around.

Mr. Sharpe

well I'd also rather not have my system fried by lightening too so will get around to fixing the ground problem.

steveinaz

Usually a common problem is that the bare cable ground wire either has paint on it, it's a bit corroded, or it's not tight in its connection. I took some sand paper to mine to shine up the copper, then re-tightened the coupler. The hum persisted though. I did a Toslink work-around to my DAC.

Mr. Sharpe

I hooked up with component video cables and rca cables and I still have hum. I'll need to get another HDMI cable. I used to have several but now that I need them, they're gone:)

RamZet

ground the cable distribution where the main feed comes into the house, ideally it should be within four feet of entering the house.
use this
http://www.ebay.com/itm/Single-ground-block-3GHz-for-coaxial-TV-F-cable-coax-RG6-satellite-digital-/141014535591?hash=item20d51f0da7:g:08IAAOSwEK9Tzago

and if you have no ground nearby use a cold water pipe:
http://www.ebay.com/itm/like/181587450165

use a solid core for the ground.

good luck.

Mr. Sharpe

Hi, odd thing here, my grandparents had almost decided to get us internet as a gift from knology. well the setup was scheduled and turns out gp's think it's way too much for 6meg net. anyways, friday comes along with the tech, told him I had canceled so I leave for 30 minutes or so to do some odds and ends and come back and guess who's hooking the wire to the house getting ready for the tech? yeah you guessed it.

Ever since then the buzz has stopped unless someone turns the bathroom light on or kitchen lights on... no idea what's up there but hey it's all good. thanks for all the replies... I will probably still get under the house and make sure the ground is good though just in case. we had a bad lightening storm the other night and everything is good.

pitdogg2

where do you live? question because some have had terrible drought and with it comes very dried out ground much deeper than ever. With that come no ground on some as the earth has dried out to below their house ground rod. Many in California have had to do some extraordinaire measures to keep a house ground.

Mr. Sharpe

I'm pretty sure the ground hasn't dried yet. Southeast alabama. We got flooded a few weeks ago and it's rained off and on since.

pitdogg2

your good some in the southwest haven't been as lucky.

RamZet

So you need to ground your cable distribution. Any cable splitter will have a spot for a grounding wire. You can order a cheap device called a cold water ground (grounds to your water pipes) from the web if you don't have a good ground nearby or if you dont want to get involved with you breaker panel.
This is best done from the main cable feed and within 4 feet of its entry into your house.

Also try a basic power conditioner at the equipment if you haven't already..