I put up my Christmas tree yesterday, with two strings of lights, each
string plugged into a separate socket on the same receptacle. About three
hours after turning the lights on, I noticed a low humming sound coming from
the room. When I unplugged one string of lights, nothing happened. When I
unplugged the other string, the humming stopped. Plug it back in, the
humming starts again.

Now here's the weird part (at least to me): the humming is not actually
emanating from the lights, the cord, the receptacle or anything else on that
entire side of the room. The hum (which is quite noticeable) seems to come
from near the ceiling 3/4 of the way across this 17-foot-long room. The hum
is present whether the regular light fixtures are on or off, and there's
nothing else electrical in the room.

The hum is just loud enough to cause me some concern -- not from the noise
(which is not unpleasant) but from its volume, which is enough to suggest
that something conceivably might not be safe. But I'm completely stymied by
the fact that the Christmas tree seems to be a ventriloquist, throwing the
noise some ten feet away. (Literally, I can stand "between" the tree and
the hum.)

Any ideas?

Jim Beaver

Do you recognize the melody?

--

Christopher A. Young
You can't shout down a troll.
You have to starve them.
..

"Jim Beaver" wrote in message
. net...
I put up my Christmas tree yesterday, with two strings of lights, each
string plugged into a separate socket on the same receptacle. About
three
hours after turning the lights on, I noticed a low humming sound
coming from
the room. When I unplugged one string of lights, nothing happened.
When I
unplugged the other string, the humming stopped. Plug it back in, the
humming starts again.

Now here's the weird part (at least to me): the humming is not
actually
emanating from the lights, the cord, the receptacle or anything else
on that
entire side of the room. The hum (which is quite noticeable) seems to
come
from near the ceiling 3/4 of the way across this 17-foot-long room.
The hum
is present whether the regular light fixtures are on or off, and
there's
nothing else electrical in the room.

The hum is just loud enough to cause me some concern -- not from the
noise
(which is not unpleasant) but from its volume, which is enough to
suggest
that something conceivably might not be safe. But I'm completely
stymied by
the fact that the Christmas tree seems to be a ventriloquist, throwing
the
noise some ten feet away. (Literally, I can stand "between" the tree
and
the hum.)

Any ideas?

Jim Beaver

Jim Beaver wrote:
I put up my Christmas tree yesterday, with two strings of lights, each
string plugged into a separate socket on the same receptacle. About three
hours after turning the lights on, I noticed a low humming sound coming from
the room. When I unplugged one string of lights, nothing happened. When I
unplugged the other string, the humming stopped. Plug it back in, the
humming starts again.

Now here's the weird part (at least to me): the humming is not actually
emanating from the lights, the cord, the receptacle or anything else on that
entire side of the room. The hum (which is quite noticeable) seems to come
from near the ceiling 3/4 of the way across this 17-foot-long room. The hum
is present whether the regular light fixtures are on or off, and there's
nothing else electrical in the room.

The hum is just loud enough to cause me some concern -- not from the noise
(which is not unpleasant) but from its volume, which is enough to suggest
that something conceivably might not be safe. But I'm completely stymied by
the fact that the Christmas tree seems to be a ventriloquist, throwing the
noise some ten feet away. (Literally, I can stand "between" the tree and
the hum.)

Any ideas?

Jim Beaver



Some questions:
If you trade the strings vs sockets, does hum stay with outlet or string ?
If stays with string, what is different about it from other ?
Have you tried any other lights, etc in same socket ?
What is above ceiling at point of hum ??
Are sockets controlled by a switch ??
Is house wiring aluminum, or copper ?
Does this branch circuit have a GFCI ?

"Jim Beaver" wrote in
. net:

I put up my Christmas tree yesterday, with two strings of lights, each
string plugged into a separate socket on the same receptacle. About
three hours after turning the lights on, I noticed a low humming sound
coming from the room. When I unplugged one string of lights, nothing
happened. When I unplugged the other string, the humming stopped.
Plug it back in, the humming starts again.

Now here's the weird part (at least to me): the humming is not
actually emanating from the lights, the cord, the receptacle or
anything else on that entire side of the room. The hum (which is
quite noticeable) seems to come from near the ceiling 3/4 of the way
across this 17-foot-long room. The hum is present whether the regular
light fixtures are on or off, and there's nothing else electrical in
the room.

The hum is just loud enough to cause me some concern -- not from the
noise (which is not unpleasant) but from its volume, which is enough
to suggest that something conceivably might not be safe. But I'm
completely stymied by the fact that the Christmas tree seems to be a
ventriloquist, throwing the noise some ten feet away. (Literally, I
can stand "between" the tree and the hum.)

Any ideas?

Jim Beaver




Amazing the number of people who never heard of Christmas Tree Light Hum
Syndrome.

Plug it back in, the humming starts again.

Maybe if you looked the lyrics up on the internet for it...

Plug it into another outlet and see what happens.

On Sun, 17 Dec 2006 02:41:54 GMT, "Jim Beaver"
wrote:

I put up my Christmas tree yesterday, with two strings of lights, each
string plugged into a separate socket on the same receptacle. About three
hours after turning the lights on, I noticed a low humming sound coming from
the room. When I unplugged one string of lights, nothing happened. When I
unplugged the other string, the humming stopped. Plug it back in, the
humming starts again.

Now here's the weird part (at least to me): the humming is not actually
emanating from the lights, the cord, the receptacle or anything else on that
entire side of the room. The hum (which is quite noticeable) seems to come
from near the ceiling 3/4 of the way across this 17-foot-long room. The hum
is present whether the regular light fixtures are on or off, and there's
nothing else electrical in the room.

The hum is just loud enough to cause me some concern -- not from the noise
(which is not unpleasant) but from its volume, which is enough to suggest
that something conceivably might not be safe. But I'm completely stymied by
the fact that the Christmas tree seems to be a ventriloquist, throwing the
noise some ten feet away. (Literally, I can stand "between" the tree and
the hum.)

Any ideas?

Jim Beaver

On Sun, 17 Dec 2006 02:41:54 GMT, "Jim Beaver"
wrote:

I put up my Christmas tree yesterday, with two strings of lights, each
string plugged into a separate socket on the same receptacle. About three
hours after turning the lights on, I noticed a low humming sound coming from
the room. When I unplugged one string of lights, nothing happened. When I
unplugged the other string, the humming stopped. Plug it back in, the
humming starts again.

Now here's the weird part (at least to me): the humming is not actually
emanating from the lights, the cord, the receptacle or anything else on that
entire side of the room. The hum (which is quite noticeable) seems to come
from near the ceiling 3/4 of the way across this 17-foot-long room. The hum
is present whether the regular light fixtures are on or off, and there's
nothing else electrical in the room.

The hum is just loud enough to cause me some concern -- not from the noise
(which is not unpleasant) but from its volume, which is enough to suggest
that something conceivably might not be safe. But I'm completely stymied by
the fact that the Christmas tree seems to be a ventriloquist, throwing the
noise some ten feet away. (Literally, I can stand "between" the tree and
the hum.)

Any ideas?


Can you examine the area the humming seems to be coming from? There
may be some bad wiring there.

Jim Beaver

--
8 days until the winter solstice celebration

Mark Lloyd
http://notstupid.laughingsquid.com

"Never underestimate the power of stupid
people in large groups"

Swap the outlets for each string. If the same outlet (not light) is
responsible for the humming, you may have a faulty socket. If not, then
maybe faulty wiring.

I wouldn't leave those on when out of the house either way.

"Jim Beaver" wrote in message
. net...
I put up my Christmas tree yesterday, with two strings of lights, each
string plugged into a separate socket on the same receptacle. About three
hours after turning the lights on, I noticed a low humming sound coming
from the room. When I unplugged one string of lights, nothing happened.
When I unplugged the other string, the humming stopped. Plug it back in,
the humming starts again.

Now here's the weird part (at least to me): the humming is not actually
emanating from the lights, the cord, the receptacle or anything else on
that entire side of the room. The hum (which is quite noticeable) seems
to come from near the ceiling 3/4 of the way across this 17-foot-long
room. The hum is present whether the regular light fixtures are on or
off, and there's nothing else electrical in the room.

The hum is just loud enough to cause me some concern -- not from the noise
(which is not unpleasant) but from its volume, which is enough to suggest
that something conceivably might not be safe. But I'm completely stymied
by the fact that the Christmas tree seems to be a ventriloquist, throwing
the noise some ten feet away. (Literally, I can stand "between" the tree
and the hum.)

Any ideas?

Jim Beaver

"Jim Beaver" wrote in message
. net...
I put up my Christmas tree yesterday, with two strings of lights, each
string plugged into a separate socket on the same receptacle. About three
hours after turning the lights on, I noticed a low humming sound coming
from the room. When I unplugged one string of lights, nothing happened.
When I unplugged the other string, the humming stopped. Plug it back in,
the humming starts again.

Now here's the weird part (at least to me): the humming is not actually
emanating from the lights, the cord, the receptacle or anything else on
that entire side of the room. The hum (which is quite noticeable) seems
to come from near the ceiling 3/4 of the way across this 17-foot-long
room. The hum is present whether the regular light fixtures are on or
off, and there's nothing else electrical in the room.

The hum is just loud enough to cause me some concern -- not from the noise
(which is not unpleasant) but from its volume, which is enough to suggest
that something conceivably might not be safe. But I'm completely stymied
by the fact that the Christmas tree seems to be a ventriloquist, throwing
the noise some ten feet away. (Literally, I can stand "between" the tree
and the hum.)

Any ideas?

You may have an acoustic effect known as a "standing wave". This is a
common effect of lower and middle audio frequencies, especially lower
audio frequencies. A resonance in your room or building may be occurring,
where a frequency or some frequencies in this hum get extra loud somewhere
far from the sound source, often close to a surface or a corner of a room.

If the sound source was large and diffuse, you might hear it best at a
location at the other end of the room where a standing wave may
concentrate the sound.

As for what the sound source is - it may be as simple as vibrating
electrostatic attraction between conductors of an easily compressible
cable. Things that are actually problematic tend to be specific points
that can be found to be sound sources.

Also, transformers may vibrate walls or floors and you may hear these
vibrations in other locations where the sound gets concentrated by a
standing wave. The sound at the source may be different from that heard
in the spot enhanced by a standing wave, because the standing wave only
concentrates some frequencies - often only one. (More properly, if a
location has more than one frequency intensified by standing waves, then
more than one standing wave is occurring and you have a set of standing
waves. Other locations will see some "hot spots", often lesser, where some
frequencies are not intensified despite being intensified at other
locations where other frwequencies are intensified.)

The frequencies accentuated are often not what would be predicted by
simpler textbook theory unless the standing wave was between parallel,
flat, openingless walls of a room whose cross section was constant between
these walls and all walls/floors/ceilings approach being infinitely rigid
or otherwise approach being perfectly unmovable by vibrations, such as
by having approaching infinite mass and density.

If you are at a corner, you may also be experiencing "horn
concentration" that can concentrate a band of frequencies. Try web
searching for "horn microphone", or consider what happens if you hold a
"passive megaphone" to your ear and aim it at a sound source. In some
cases, horn effects and standing waves both come into play - you can get
standing waves in a horn.

Now for a horn-enhanced buzz story of mine: I have a torchiere lamp
with a socket for screw base lamps and a somewhat horn-shaped "shade"/
"directyor/reflector" to make most of the light go towards the ceiling.
Compact fluorescents that buzz but usually not noticeably, do buzz
noticeably in that "horn" due to an acoustic effect actually known as
"horn loading"!

- Don Klipstein )

Jim Beaver wrote:
I put up my Christmas tree yesterday, with two strings of lights, each
string plugged into a separate socket on the same receptacle. About three
hours after turning the lights on, I noticed a low humming sound coming from
the room.
[snip]
the humming is not actually
emanating from the lights, the cord, the receptacle or anything else on that
entire side of the room. The hum (which is quite noticeable) seems to come
from near the ceiling 3/4 of the way across this 17-foot-long room.

I'd suggest process of elimination. Does it only happen with Christmas
tree lights, or does some other electrical device plugged into that
outlet cause it? Is it only that one string of lights, or does the
sound occur with any string of lights plugged into that outlet? Does
the hum occur regardless of what is on in that room, or what is on in
other rooms? How old is the house? The particular electric circuit(s)
in which the Christmas tree lights are plugged?

Today's Christmas tree lights don't draw much more current than a
standard lamp, so it's not as if your tree is more of a burden than a
couple of lamps plugged into an outlet.
(http://christmas.howstuffworks.com/c...as-lights2.htm) If my lights
were causing an electric hum, I'd want it checked out before I appeared
on the 11 o'clock news with the graphic under my face "Christmas tree
burned his house down".

"Reed" wrote in message
k.net...
Jim Beaver wrote:
I put up my Christmas tree yesterday, with two strings of lights, each
string plugged into a separate socket on the same receptacle. About
three hours after turning the lights on, I noticed a low humming sound
coming from the room. When I unplugged one string of lights, nothing
happened. When I unplugged the other string, the humming stopped. Plug
it back in, the humming starts again.

Now here's the weird part (at least to me): the humming is not actually
emanating from the lights, the cord, the receptacle or anything else on
that entire side of the room. The hum (which is quite noticeable) seems
to come from near the ceiling 3/4 of the way across this 17-foot-long
room. The hum is present whether the regular light fixtures are on or
off, and there's nothing else electrical in the room.

The hum is just loud enough to cause me some concern -- not from the
noise (which is not unpleasant) but from its volume, which is enough to
suggest that something conceivably might not be safe. But I'm completely
stymied by the fact that the Christmas tree seems to be a ventriloquist,
throwing the noise some ten feet away. (Literally, I can stand "between"
the tree and the hum.)

Any ideas?

Jim Beaver

Some questions:
If you trade the strings vs sockets, does hum stay with outlet or string ?

The sound stays with the socket, not the string.


If stays with string, what is different about it from other ?
Have you tried any other lights, etc in same socket ?

No. Will try.

What is above ceiling at point of hum ??

I've now actually tracked the sound to a wall on the exact diagonal opposite
side of the room. There's another outlet there. The hum is very loud
(comparatively) at that point. The outlet is cool to the touch. On the
opposite (house external) side of the wall from this new socket is the timer
assembly for my sprinkler/yard-lighting system. Coincidence?

Are sockets controlled by a switch ??

No.

Is house wiring aluminum, or copper ?

I don't know, but the wiring is approximately three years old (the age of
the house).

Does this branch circuit have a GFCI ?

Not as far as I can determine.

Jim

"Jim Beaver" wrote in message
. net...

"Reed" wrote in message
k.net...
Jim Beaver wrote:
I put up my Christmas tree yesterday, with two strings of lights, each
string plugged into a separate socket on the same receptacle. About
three hours after turning the lights on, I noticed a low humming sound
coming from the room. When I unplugged one string of lights, nothing
happened. When I unplugged the other string, the humming stopped. Plug
it back in, the humming starts again.

Now here's the weird part (at least to me): the humming is not actually
emanating from the lights, the cord, the receptacle or anything else on
that entire side of the room. The hum (which is quite noticeable) seems
to come from near the ceiling 3/4 of the way across this 17-foot-long
room. The hum is present whether the regular light fixtures are on or
off, and there's nothing else electrical in the room.

The hum is just loud enough to cause me some concern -- not from the
noise (which is not unpleasant) but from its volume, which is enough to
suggest that something conceivably might not be safe. But I'm
completely stymied by the fact that the Christmas tree seems to be a
ventriloquist, throwing the noise some ten feet away. (Literally, I can
stand "between" the tree and the hum.)

Any ideas?

Jim Beaver

Some questions:
If you trade the strings vs sockets, does hum stay with outlet or string
?

The sound stays with the socket, not the string.


If stays with string, what is different about it from other ?
Have you tried any other lights, etc in same socket ?

No. Will try.

What is above ceiling at point of hum ??

I've now actually tracked the sound to a wall on the exact diagonal
opposite side of the room. There's another outlet there. The hum is very
loud (comparatively) at that point. The outlet is cool to the touch. On
the opposite (house external) side of the wall from this new socket is the
timer assembly for my sprinkler/yard-lighting system. Coincidence?

Are sockets controlled by a switch ??

No.

Is house wiring aluminum, or copper ?

I don't know, but the wiring is approximately three years old (the age of
the house).

Does this branch circuit have a GFCI ?

Not as far as I can determine.

Jim

Following up with further investigation:

The humming is definitely coming from the timer for my yard lighting and/or
sprinklers -- probably the yard-lighting, as it turns out the "3 hr. delay"
I mentioned before the humming starts is actually a result of it my yard
lights coming on three hours after I plugged in the tree. If the yard
lights are on and I turn on the tree lights, the humming starts. If the
yard lights are off, no hum.

The housing for my yard-lights is behind some brush, hard to get to in the
dark, but I was able to get my hand on it and while the cover is definitely
vibrating, it seems cool to the touch.

Also: unplugging the Christmas lights and plugging a four-bulb torchiere
lamp into the same socket does NOT result in a humming sound. Only the
Christmas tree lights do it. The lights are NOT those little mini-lights
but GE Super C7 "ceramic look" lights, made for Christmas trees. There are
two strings, but one has a section not working, so in all probability the
load is less on that one, accounting for the difference in hum. In
actuality, either string causes the hum if plugged in to the top of the
socket pair, one just causes a louder hum. If both strings are plugged into
both sockets, there is a slightly louder hum, but it's clearly the top
socket of the two that results in the most hum. All of that said, though,
the hum is coming from fifteen-twenty feet away, from the yard-light timer
box on the outside opposite wall.

Now that I've apparently isolated the locale, does anyone have a sense of
whether there's a safety issue yet?

Jim

call a licensed electrician from NJ.
I hear they need the work.

don't they RBM




"Jim Beaver" wrote in message
. net...
I put up my Christmas tree yesterday, with two strings of lights, each
string plugged into a separate socket on the same receptacle. About three
hours after turning the lights on, I noticed a low humming sound coming
from the room. When I unplugged one string of lights, nothing happened.
When I unplugged the other string, the humming stopped. Plug it back in,
the humming starts again.

Now here's the weird part (at least to me): the humming is not actually
emanating from the lights, the cord, the receptacle or anything else on
that entire side of the room. The hum (which is quite noticeable) seems
to come from near the ceiling 3/4 of the way across this 17-foot-long
room. The hum is present whether the regular light fixtures are on or
off, and there's nothing else electrical in the room.

The hum is just loud enough to cause me some concern -- not from the noise
(which is not unpleasant) but from its volume, which is enough to suggest
that something conceivably might not be safe. But I'm completely stymied
by the fact that the Christmas tree seems to be a ventriloquist, throwing
the noise some ten feet away. (Literally, I can stand "between" the tree
and the hum.)

Any ideas?

Jim Beaver