While trying to connect wireless speakers for the Xmas season I noticed that
on the receiver end I get a distinct hmmmmmmmm. I tried different plugs
and turned off all the fluorescent lights I could find. Still there.
Also I don't think any appliances and/or chargers were functioning at the
time either.

Can some of you please suggest what other areas I might check?

On Dec 3, 8:05*am, Bob M wrote:
While trying to connect wireless speakers for the Xmas season I noticed that
on the receiver end I get a distinct hmmmmmmmm. *I tried different plugs
and turned off all the fluorescent lights I could find. *Still there. *
Also I don't think any appliances and/or chargers were functioning at the
time either.

Can some of you please suggest what other areas I might check? *

Yours or neighbors cordless phones and equipment can be an issue, is
it 900mhz, alot of things use the standard frequencies, outlet wiring
and ground can have effect, try turning off all breakers to see if you
can isolate it, is it a wide plug that goes in one way, reverse the
polarity, you have to experiment, or maybe the hmm is a defect, take
it to the neighbors and try it.

"Claude Hopper" wrote in message
...
Bob M wrote:
While trying to connect wireless speakers for the Xmas season I noticed
that
on the receiver end I get a distinct hmmmmmmmm. I tried different plugs
and turned off all the fluorescent lights I could find. Still there.
Also I don't think any appliances and/or chargers were functioning at the
time either.

Can some of you please suggest what other areas I might check?

Probably a leaky power supply. Or a really cheap one.


Some wireless speakers aren't designed all that well, and suffer from the
very problem you describe. Even good models, as they age, begin to suffer
this problem in some cases. The electrolytic capacitor(s) used to filter the
power supply get dry and provide less filtering. Can you try running them
off a battery supply or a known good source of DV to see if they still have
the problem? This would separate your problem as being either "conducted
EMI" versus "radiated EMI". Conducted comes from the power line or power
source / power supply whereas radiated comes from fluorescent lighting or
other nearby sources of RF interference.

Smarty

First connect wired speakers to your receiver and check for a hum. This is a
common, but tricky to diagnose, problem in audio systems. If your amp has a
hum that is heard through wired speakers, it is a ground loop problem. This
is caused by multiple groundings. Only one source of ground is recommended
as a loop is formed when multiple items are interconnected while plugged
into grounded outlets, this includes the grounded sheath of "cable TV"
cabling. Only the amp should be grounded all other equipment should not be
grounded. A grounded "cable TV" cable may need an isolation device added in
line with the cable.

If you have no hum through wired speakers, then it is the wireless system
picking up the hum or the circuitry is creating the hum.

"Bob M" wrote in message
...
While trying to connect wireless speakers for the Xmas season I noticed
that
on the receiver end I get a distinct hmmmmmmmm. I tried different plugs
and turned off all the fluorescent lights I could find. Still there.
Also I don't think any appliances and/or chargers were functioning at the
time either.

Can some of you please suggest what other areas I might check?

In article ,
Bob M wrote:

While trying to connect wireless speakers for the Xmas season I noticed that
on the receiver end I get a distinct hmmmmmmmm. I tried different plugs
and turned off all the fluorescent lights I could find. Still there.
Also I don't think any appliances and/or chargers were functioning at the
time either.

Can some of you please suggest what other areas I might check?


Light dimmers are a possible source.

It's also possible the origin, whatever it may be, isn't even on your
property.

Old wireless 'AM' intercoms were notorious for picking up 60Hz hum's.

Good Luck,

Erik

On Wed, 03 Dec 2008 09:05:17 -0500, Bob M wrote:

While trying to connect wireless speakers for the Xmas season I noticed that
on the receiver end I get a distinct hmmmmmmmm. I tried different plugs
and turned off all the fluorescent lights I could find. Still there.
Also I don't think any appliances and/or chargers were functioning at the
time either.

Can some of you please suggest what other areas I might check?

Since they're wireless, I assume there's a receiver and a transmitter?

Could be a ground loop at the transmitter. I would try flipping the
transmitter linecord 180 degrees in the socket if its not polarized.
Make sure its in the same duplex outlet as the audio source or at
least on the same circuit. As a test, just plug it in and disconnect
any and all connections to the audio equipment.

Then unplug the transmitter. If the hum is still there its the
receiver's fault, its either a bad receiver or a bad receiver design.
I'm assuming there are no other wires going to the receiver, just a
line cord.

If the hum goes away when the transmitter is unplugged, and there are
no other audio connection to it, then its a fair guess the transmitter
is at fault and again, thats the way it works, badly, or is broken.