Quote:
Originally Posted by MRX37
Something's wrong with these DTV boxes if they can put out so much RF interference that they mess up the picture on a TV.
The FCC should be made aware of this...
Apart from that, maybe some foil or mesh around the DTV box will reduce the RF emaniating from it...
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The shielding of the DTV box may cause it to overheat, and there is no need, as any vent slot on that device is small enough not to be of sufficient aperture to admit signals that would cause interference in the low VHF band. But there is probably enough of that digital hash spilling out via its power cord--despite efforts to filter it at the point of power entry. Attempts to shield this will probably prove futile, or at least unreliable, as the radiation would simply come from the house wiring after that.
Also the set being using as a monitor for this DTV is of a bygone era.
Let me explain: Late model sets with the coaxial antenna input have better shielding; the input connector is actually part of the completely shielded VHF/UHF/Cable tuner assembly, so there is no exposure to in-the-air interference. A shieled coaxial cable pipes the signal directly from the output of the DTV converter to that tuner without outside interference being able to penetrate the shield of the cable. And all the electronics in the typical set are at the bottom of the set, and away from any nasties you might place on the top. OK, now that we've covered this let's look at the older set....
In the old console there is usually a set of twinlead terminals at the back of the set. While some sets have a "balun" to convert the balanced 300ohm to a shielded cable at 75ohm impedance to run to the tuner at the top corner of the cabinet (right under that converter in the posted pic!), the balun is usually an unshielded coil assembly just behind the screw terminals. But many sets of that day had the balun assembly on the tuner and a short length of twinlead running from there to the screws at the back of the set. That twinlead is fair game for any extraneous interference.
If the latter best describes the situation the best bet may be to disconnect the balun assembly, and try to tap into the direct unbalanced input of the tuner, and run RG-6 to a coax nipple such as used in wall plate applications fit into a drilling in the set's back. It is best to obtain a schematic for the set to ascertain what this conversion will actually involve.
The trash emanating from the DTV is still likely within FCC guidelines as regards how much spurious radiation it may produce. While your own set may complain it is not likely to bugger up your neighbor's TV--or even a set in the next room.