Disconnected from cable (Satellite) in one room.

How to isolate annoying background hum.

As long as the music or movie is playing, you can forget about it, at least until a quiet passage occurs, then there it is again: HUMMMMMMM! Be gone, bad hum, you think. But, like a bad odor at the back of the fridge, it takes some dogged persistence to track it down and eliminate it.

Hum is a constant low-frequency buzz, usually at about 60 Hz or 120 Hz, which results from voltage differences between true "ground" (what you'd get shoving a copper pipe into the ground) and the electrical "ground" of your receiver's chassis, the incoming cable-TV feed, or any video or audio components interconnected within your system, including powered subwoofers. When this voltage differential exists, it's called a "ground loop," and the hum it produces is darned annoying. You'll hear the hum mainly from the subwoofer because it's a low-frequency noise, but there will also be hum from your floorstanding front speakers or even compact bookshelf models.

First, try disconnecting your subwoofer from the coaxial sub cable from your AV receiver but leave the subwoofer turned on. Does the hum go away? If it does, then the ground loop is entering the system from your AV receiver and/or your cable-TV system set-top box (or satellite dish and decoder).

Disconnect the incoming TV-cable or satellite feed to a set-top box or to your TV and the A/V receiver. If the hum disappears (and you don't use a satellite dish) complain to the cable-TV company. They may know what you need and supply you with a ground-isolating transformer. If they don't know what you are talking about you'll need to order a video ground isolator and install it in-line with the TV cable before it enters your set-top cable-TV box. Axiom has special wide-band isolation transformers that will not interfere with any digital TV or HDTV signal. (N.B. You CANNOT use one of these with a satellite decoder box.)

Before you order one, you can try plugging your subwoofer into a different AC outlet in the room, ideally one that is not on the same circuit as your AV receiver and video equipment (TV, DVD player, sat or cable TV box, etc.) That may solve the problem. If it doesn't, see if the back panel of your sub has a "ground-lift screw". It will be labeled as such. Just remove it. That may remove the hum. If it doesn't and you have a standard cable-TV feed (not a dish), then order the ground-isolation transformer. (Axiom has special wide-band isolation transformers that will not interfere with any digital TV or HDTV signal.)
Axiom Audio Ground Isolator

If that still doesn't eliminate the hum, or if you use a satellite dish video feed, then you could try one of these from Radio Shack, which goes between the subwoofer and the coaxial cable from the receiver's subwoofer output.

With persistence, all ground-loop problems can be solved.

Hope it helped..

Have a nice day...

If you are connected to a high definition cable box or satellite tv box you would not need to turn to channel 3 on your television. The television would need to be in the right input either component or hdmi. If someone connected the tv to the cable box or satellite tv box with a coax cable like an antenna cable then the tv channels will be available on channel 3 as well but they will not display in high definition. You change channels with the cable box/satellite tv box remote control. If the above is not correct and you are only connected to an antenna cable and not to a cable box or satellite tv box you will need to complete a channel search from the tv menu. It sounds like you are using a cable box/satellite tv box and that the tv is on the wrong input. If the cable box/satellite tv box is not working (i.e. just a black screen) on your television than that is a different matter entirely.

I should be channel 3 or 4. This assumes that this coax cable is coming out as a TV R.F. connection of a Dish Network Box (Satellite Receiver) intended for direct connection to an old fashioned NTSC (channels 2-13, 14-83, possibly even has cable channels depending on how old?) TV.

If this coax is the output of a coax going directly to the Satellite Dish or through what might might look to you like some kind of fancy splitter (called a Multi-Switch) the you WOULD NOT want to hook that to your old NTSC tv. The frequency is too high ... etc. etc... you would need Dish Box (as you call it) a.k.a. a Satellite receiver - with a good and active satellite card from your provider.

Hi Martin,

A wiring Schematic is not that you should be looking. What you need is large feeders to understand hot to connect to various ports to give your desired output.

Disconnect the cable in the interior of the coach and connect it directly to the satellite receiver. You may have to attach an extra length of cable to reach. You can then connect your sat cable to the outside cable connector.

If this is working in another room I suggest you check the connection from wherever that particular wire comes from ex. splitter or directle from the antenna I do not know where you tapped in that line. I hope this helps you out.

Usually need a second receiver. Cannot just split signal. With some cable providers you can split the cable before it hits the cable box for basic cable channels.

Suggest contacting Cable Company if does not work.

Thanks!

you may bypass the box by using a straight connector, find the cable that lead to the TV room and connect it to the cable from the aerial antenna.

The only way this would work ( and this applies to any form of cable/satellite box) so the only way this works is if the TV that has the satellite connected to it has a video output normally indicated with the color yellow, but you still need sound that normally is the red and white (RCA cables). So the first tv needs to have video and sound outputs and the TV you want it connected to needs to have the video and sound inputs. depending on the distance between the 2 TV's this might prove to be rather difficult. it would be easier to run the coax cable from the main satellite box to the room where you have the 2nd TV however to do this you would need to move the satellite box back and forth. Hope this helps

You should be able to use your remote control to do this.Your channel 73 is more than likely UHF 73 so you need to put your tv in the antenna setting rather than cable setting. Once you do this just input 73 with your remote. Hope this helps! Stargazer