OT: House wiring ideas needed

A couple of off-the -wall suggestions: During the daylight, turn off everything in the house or unplug it. Go check the power meter and see if it's recording any usage.
Is the house on a well? Could be a short to the well casing. Any close neighbors? They could be stealing power with a long miss-wired extension cord.
We had house with a basement in Portland. Part of the wiring that had been done in the basement ceiling had the hot and neutral reversed.
Does the house have metal siding? If so, could be source of AC, if not properly installed.
I know, these are all weird suggestions, but then so is the problem!
Paul
Reply to
KD7HB
Loading thread data ...
If it still appears the speaker is buzzing, try shorting the input terminals to see if it makes any difference.
Laurie Forbes
Reply to
Laurie Forbes
Impossible if the voice coils were open circuit - because there would be no current flow, and therefore no magnetic field generated. If there is a crossover of some sort, it could be a possibility.
Reply to
clare
Get a "trtansformer direct box" for the instruments - allows you to "lift" the ground or invert the ground to the instrument and almost invariably eliminates the hum when properly set.
Reply to
clare
OK then the loop shouldn't be the problem.
I noticed you said CFLs, they are VERY noisy rf wise.
As a test to see if it's the wiring in that room you could run a lead over to another room or neighbors house and see if you still get the hum in the room.
Reply to
Steve W.
And there's pickup on audio equipment.
What's probably happening, is that current loops (knob-and-tube wiring) are inducing ground loop currents in the audio stuff.
The closest socket to the breaker panel should be the quietest; put an extension cord there and plug all the equipment into it, if possible. The widely-separated wires in the wall are making magnetic fields, the closely-spaced wires in the extension cord are much less troublesome.
Since this is a basement, probably the upper floor wiring is distant enough to be only a minor problem, but you might consider turning off power to high-current items on nearby circuits (a water heater or furnace can tolerate an hour's practice time turned off).
Reply to
whit3rd
Reconnect it. It's a code requirement that house plumbing be bonded to (i.e. wired to) the ground at your breaker panel; This in no way REPLACES the stake-in-the-soil ground rod, it rather ensures that your pipes aren't a shock hazard in case of a wiring fault.
Reply to
whit3rd
Yup, an older home with little grounding. So, there are wires running all over the place, radiating 120 V fields. Now, usual Romex isn't shielded, either, so it still radiates a strong field, at least if you are real close to it.
Well, it is likely there is a lot of ungrounded stuff in there. Does it have a hot air furnace? Is that grounded? If not, all the typical ductwork may be radiating, and that is a lot of surface area. Just for safety reasons, you ought to ground stuff in the basement. The metal reflectors on typical fluorescent lights should be grounded, I'm guessing that is what you are talking about. Without grounding, they become big transmitting antennas, too.
It may also be that the ground rod for the entire electrical system has dried out or corroded away, and so there is NOTHING in the house that is well grounded.
Jon
Reply to
Jon Elson
GOOD LORD! Now, that is getting scary! I just assumed powered speakers in the previous messages, but this indicates a REALLY strong radiated field.
Jon
Reply to
Jon Elson
Yup, VERY strong possibility, there is a big magnetic field from something in the house, and it was getting into the big coils in the crossover network, which are typically air-core to avoid saturation.
Jon
Reply to
Jon Elson
snipped-for-privacy@krl.org wrote in rec.crafts.metalworking on Fri, 24 Dec 2010 04:43:26 -0800 (PST):
That's what I was thinking too. But I was thinking that due to some bad wiring, the return path was in another neutral somewhere. That would make a large current loop, creating a magnetic field.
I might try shutting off all the breakers in the panel to see if that fixes the problem. If it does, then turn them back on, one at a time, to see witch one(s) are causing it. Check the neutral connections in the panel too.
Reply to
dan
More likely power lines outside carrying the high current and having a large field intensity.
I had a pair of corner mounting wall speakers that one developed some hum. It was a bad DC supply for the main magnet coil. Yea - not permanent magnets but DC magnets.
Martin
Reply to
Martin Eastburn
WRONG. Metal water piping is required to be bonded to the grounding electrode system -- this is not in order to ground the *electrical* system, but to ground the *plumbing* system to ensure that the pipes cannot become live.
OP: Ignore this dangerous advice. DO NOT disconnect the water piping from the grounding electrode system. The remainder of the post is good sense, but this is dangerous.
Reply to
Doug Miller
I'll kinda half dissagree. DEpends on WHERE he had it connected. Do NOT have one end of the "ground" wire grounded to the panel, and the other to the water pipe. That is a "no-no" on several levels.
Connect the outlet grounds to the PANEL GROUND ONLY - and ground the water pipes to the panel ground. Connect the panel ground to approved driven equipment ground rods. The COMMON GROUND POINT MUST BE THE PANEL.
Reply to
clare
Romex generally is not a serious noise radiator because of the "common mode " phenomenon. both wires radiate the same "noise" in close proximity and tend to "bind" the emission. A whole lot more effective with twisted pairs, obviously - but the old ungrounded "romex" (NMD) cable is not nearly as "noisy" as the old Knob and tube, particularly the old "ring topology" Knob and tube.
Reply to
clare
OK, so not "bare speakers" but "speaker systems" with crossover networks - which are tuned tank circuits, to some extent, and can pass significant current within themselves at certain frequencies. A "bare speaker" could NOT POSSIBLY exhibit the behaviour, under ANY conditions.
Reply to
clare
As you say, Romex doesn't radiate much magnetic field, as the current returns through a wire only a fraction of an inch away. But, it still does radiate some electrical field. The grounded wires absorb some of the field, but there is still some electric field radiation from the hot wire. But, that should be a very short-range phenomenon. To have a massive field that can be detected all over the basement, it takes something big, like heating ducts or the metal reflectors on 4' fluorescent fixtures. The metal grid for a suspended ceiling with fluorescent lamps in it would be the sort of thing that could do this.
I'm going with electrical field, because it takes some real energy to produce massive AC magnetic fields. Large currents flowing through conduits could maybe do it, but there really shouldn't be such currents flowing. But, with lots of ungrounded fixtures, etc., the ceiling grid going at least partially live is quite likely.
Jon
Reply to
Jon Elson
(raises hand and waves furiously) I know! I know!
Yer prolly not using HUMbuckers.
I've never heard an amp that was cranked up which did NOT hum with a gitfiddle plugged into it. Nature of the beast. That's one reason humbuckers were invented, an attempt to tame it.
-- Remember, in an emergency, dial 1911.
Reply to
Larry Jaques
Steve, I just saw the original post and have more information now.
Are you sure that the existing ground rod is proper and working, and that all connections to it are corrosion-free? I've felt warm ground rods where corrosion had build up between the connector and the rod, giving some resistance. It looked good but didn't function well.
-- Remember, in an emergency, dial 1911.
Reply to
Larry Jaques
Thirded.
Have him remain there where he can hear the buzz while someone removes the speaker. I'll bet he can still hear the buzz there, and it's coming from something else (if not the lighting.)
Right, _expensive_ low-grade stuff created to distort electrical signals on purpose. ;)
-- Remember, in an emergency, dial 1911.
Reply to
Larry Jaques

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.