G
Guest
In sci.electronics.design John O'Flaherty said:
See "humbucker" pickups.
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See "humbucker" pickups.
G
GregS
Power conditioners can introduce noise. Guitars are terrible for noise.
I see Faraday cages all the time here. Mostly a 5 sided box with the front open. Most
of these cages are made from aluminum window screens. They reduce electrostatic
noise. Many times power strips are toward the rear of the cage, but NO AC 60 Hz
power can enter the cage area via power cords. I carry a electrostatic and magnetic
noise sniiffer. I recently added a photodiode so I could hear light noise.
Sources of the electrostatic noise can easily be tracked down, but ground
loops and 60 Hz wiring are simply tricky. Also around here, we suggested there be problems, so
new building are constructed with aluminum backed wallboard. It helps, but of course
its not perfect, but gets the job done of reducing intense fields. Having the AC wiring contained
in a conduit also reduces electrostatic noise to a very high degree. You can also
buy shielded AC cords. Isolation transformers usually help.
greg
J
John Jardine.
CS said:
That massive 50Hz peak looks distinctly odd. Maybe it's not actual 'pickup'
but conducted mains leakage type currents.
Curiosity piqued, I stuck a 1.5H coil into a X100 lo-noise amp feeding a
normal spectrum analyser, looking at 20Hz to 1kHz with a 5Hz filter.
Just sat it on the bench near the incoming feeder, the only other powered
kit being the PC. Virtually no 50Hz component was present (-90dBm, 7uV) but
big peaks of 150Hz, 250Hz, 350Hz, 450Hz, all about 20dB higher at
about -70dBm, 70uV.
That was it though, all other components were sitting in the grass at
the -100dBm level.
Powering up a lot of other kit made little change to the display.
john
C
CS
U¿ytkownik "Rene Tschaggelar said:
Thank you very much
You need two cages inside each other connected
Is this due the wavelength ..? (one point at node, one at maximum = short)
How does this quantum limit work..?
Makes me curious..
Is this due the wavelength ..? (one point at node, one at maximum = short)
How does this quantum limit work..?
Makes me curious..
P
Phil Allison
"CS"
** That hum is being injected MAGNETICALLY into your guitar's pickups.
A Faraday cage will have NO effect on it - whatever !!
FORGET IT !!
Your ONLY option to eliminate the hum is to get a guitar that has "
hum-bucking " pickups.
The hum problem YOU are having is WHY they were invented, way back in the
1960s.
Most musicians learn to live with it by orienting themselves when playing
to minimise the hum and/or using a *noise gate* to silence the hum when the
guitar is not being played.
BTW
I can hardly believe how many FUCKWITS posters here have given you the
WRONG answer for such a common problem.
....... Phil
** That hum is being injected MAGNETICALLY into your guitar's pickups.
A Faraday cage will have NO effect on it - whatever !!
FORGET IT !!
Your ONLY option to eliminate the hum is to get a guitar that has "
hum-bucking " pickups.
The hum problem YOU are having is WHY they were invented, way back in the
1960s.
Most musicians learn to live with it by orienting themselves when playing
to minimise the hum and/or using a *noise gate* to silence the hum when the
guitar is not being played.
BTW
I can hardly believe how many FUCKWITS posters here have given you the
WRONG answer for such a common problem.
....... Phil
H
Howard Eisenhauer
Q.- Do you have a PC & monitor running in your studio? Nearby?? The
switching supplies in these things, especially the cheap "No Name"
ones, are just F___ing horrible for generating noise, both radiated &
back fed on power lines. Those harmonic spikes on your mains
certainly arn't coming from your power utility, something is
generating them locally. If your guitar is picking them up out of the
air its VERY local. Have you tried connecting a 600 ohm termination
to the cable instead of the guitar to see if you still have the noise?
Beyond that I'd have to say theres also a problem with the cable
shielding setup, when properly terminated audio cables shouldn't have
any problem with cancelling out common mode or shielding differential
noise.
H.
switching supplies in these things, especially the cheap "No Name"
ones, are just F___ing horrible for generating noise, both radiated &
back fed on power lines. Those harmonic spikes on your mains
certainly arn't coming from your power utility, something is
generating them locally. If your guitar is picking them up out of the
air its VERY local. Have you tried connecting a 600 ohm termination
to the cable instead of the guitar to see if you still have the noise?
Beyond that I'd have to say theres also a problem with the cable
shielding setup, when properly terminated audio cables shouldn't have
any problem with cancelling out common mode or shielding differential
noise.
H.
P
Phil Allison
"Howard Eisenhauer"
** Kindly read this and learn something about magnetically induced hum.
http://en.wikipedia.org/wiki/Humbucker
....... Phil
** Kindly read this and learn something about magnetically induced hum.
http://en.wikipedia.org/wiki/Humbucker
....... Phil
P
Phil Allison
"Phil Allison"
to CS
** That hum is being injected MAGNETICALLY into your guitar's pickups.
A Faraday cage will have NO effect on it - whatever !!
FORGET IT !!
Your ONLY option to eliminate the hum is to get a guitar that has "
hum-bucking " pickups.
The hum problem YOU are having is WHY they were invented, way back in the
1960s.
** OK - it was actually developed by Seth Lover in the 1955:
http://en.wikipedia.org/wiki/Humbucker
........ Phil
to CS
** That hum is being injected MAGNETICALLY into your guitar's pickups.
A Faraday cage will have NO effect on it - whatever !!
FORGET IT !!
Your ONLY option to eliminate the hum is to get a guitar that has "
hum-bucking " pickups.
The hum problem YOU are having is WHY they were invented, way back in the
1960s.
** OK - it was actually developed by Seth Lover in the 1955:
http://en.wikipedia.org/wiki/Humbucker
........ Phil
R
Rene Tschaggelar
The first shield radiates to the inside what the
induced currents on it surface flow. The efffects
are multiple. You have to visualize the multitude
of frequencies and fields that are possible to
propagate.
The worst are nearfield magnetic, eg a train passing
5m from your house. At the time of CRTs, it was
impossible to work during the time the current flowed
through the rails. And it wasn't shieldable. As
John Larkin said, for a decent magnetic shielding,
eg 120dB up, you need substantial amounts of iron.
How does this quantum limit work..?
Makes me curious..
Me too... I haven't read through the whole theory yet.
Just the abstract. I guess the -180dB are the thermal
noise floor at room temperature in comparison to the
ambient EM-noise.
Rene
C
CS
U¿ytkownik "Phil Allison said:
Hmmmm then why every good electric guitar (including mine) has a Faraday's
cage ( conductive paint or copper foil) inside - just for fun ?
I have two humbuckers in my guitar and i don't need another one.
C
CS
U¿ytkownik "Howard Eisenhauer said:
That signal on my analyzer picture was recorded with crt monitor turned off.
All those spikes get louder when i move my guitar closer to the cable (going
to a ceiling lamp) inside the wall. The buzz gets quieter when i switch the
light off ( i even tried this experiment without a lightbulb to see if the
buzz comes really from the wire and not from a working lightbulb )
????? I know almost nothing about electronics , so if you can explain in
layman terms i would be grateful
I think my cable is ok. It is high quality and short - it gives me no noise
when the guitar volume is turned all the way down.
P
Phil Allison
"CS"
** That is a simple * ELECTROSTATIC * shield - you jerk off.
Has NO effect on a MAGNETIC field .
** What guitar?
What "humbuckers" ??
I reckon YOU are full of SHIT !
........ Phil
Hmmmm then why every good electric guitar (including mine) has a Faraday's
cage ( conductive paint or copper foil) inside - just for fun ?
** That is a simple * ELECTROSTATIC * shield - you jerk off.
Has NO effect on a MAGNETIC field .
I have two humbuckers in my guitar and i don't need another one.
** What guitar?
What "humbuckers" ??
I reckon YOU are full of SHIT !
........ Phil
P
Phil Allison
"CS"
** That hum is being injected MAGNETICALLY into your guitar's pickups.
A Faraday cage will have NO effect on it - whatever !!
FORGET IT !!
Your ONLY option to eliminate the hum is to get a guitar that has "
hum-bucking " pickups.
The hum problem YOU are having is WHY they were invented, way back in the
1960s.
Most musicians learn to live with it by orienting themselves when playing
to minimise the hum and/or using a *noise gate* to silence the hum when the
guitar is not being played.
BTW
I can hardly believe how many FUCKWITS posters here have given you the
WRONG answer for such a common problem.
....... Phil
** That hum is being injected MAGNETICALLY into your guitar's pickups.
A Faraday cage will have NO effect on it - whatever !!
FORGET IT !!
Your ONLY option to eliminate the hum is to get a guitar that has "
hum-bucking " pickups.
The hum problem YOU are having is WHY they were invented, way back in the
1960s.
Most musicians learn to live with it by orienting themselves when playing
to minimise the hum and/or using a *noise gate* to silence the hum when the
guitar is not being played.
BTW
I can hardly believe how many FUCKWITS posters here have given you the
WRONG answer for such a common problem.
....... Phil
P
Phil Allison
""CS" = Complete Shithead
** That hum is being injected MAGNETICALLY into your guitar's pickups.
A Faraday cage will have NO effect on it - whatever !!
FORGET IT !!
Your ONLY option to eliminate the hum is to get a guitar that has "
hum-bucking " pickups.
The hum problem YOU are having is WHY they were invented, way back in the
1960s.
Most musicians learn to live with it by orienting themselves when playing
to minimise the hum and/or using a *noise gate* to silence the hum when the
guitar is not being played.
BTW
I can hardly believe how many FUCKWITS posters here have given you the
WRONG answer for such a common problem.
....... Phil
** That hum is being injected MAGNETICALLY into your guitar's pickups.
A Faraday cage will have NO effect on it - whatever !!
FORGET IT !!
Your ONLY option to eliminate the hum is to get a guitar that has "
hum-bucking " pickups.
The hum problem YOU are having is WHY they were invented, way back in the
1960s.
Most musicians learn to live with it by orienting themselves when playing
to minimise the hum and/or using a *noise gate* to silence the hum when the
guitar is not being played.
BTW
I can hardly believe how many FUCKWITS posters here have given you the
WRONG answer for such a common problem.
....... Phil
Is this due the wavelength ..? (one point at node, one at maximum = short)
What distance and hole diameter should be used?, a prof suggested 1/2
wavelength for the holes at least. But things like micros have 1/65 wavelength.
I well not accept trains then
Another perspective on this scale is that atoms work as wavelength conductors
depending on how large the holes between them are. So any glass have holes that
are at least 700 nm wide. While an parabole could use cm/mm wide holes and
still be conductive enough for radio signals.
What distance and hole diameter should be used?, a prof suggested 1/2
wavelength for the holes at least. But things like micros have 1/65 wavelength.
I well not accept trains then
Another perspective on this scale is that atoms work as wavelength conductors
depending on how large the holes between them are. So any glass have holes that
are at least 700 nm wide. While an parabole could use cm/mm wide holes and
still be conductive enough for radio signals.
C
CS
U¿ytkownik "Phil Allison said:
It clearly has a big effect on power wires in my walls - i can hear a loud
noise if i put my emg707 very close to a wire in my wall and that noise gets
much quieter if i turn my guitar 180 degrees to face away from the wall and
hold the pickup at the same distance to the wire.
good enough - emg707 & emg81-7
Like everyone else few hours after a good meal
J
jasen
guitars use unbalanced cables.
Bye.
Jasen
P
Phil Allison
"CS" = a Complete Shithead
** YOU ARE A COLOSSAL FUCKING IDIOT !!! .
That scenario PROVES the direct opposite !!!!!!!!!!!!!!!!!!!!!
** Damn shame those two heaps of shit do not actually *buck* hum very well.
Try a " Les Paul " with original PAF Gibson humbuckers.
Bet it is silent as a graveyard in the same room.
........ Phil
** YOU ARE A COLOSSAL FUCKING IDIOT !!! .
That scenario PROVES the direct opposite !!!!!!!!!!!!!!!!!!!!!
** Damn shame those two heaps of shit do not actually *buck* hum very well.
Try a " Les Paul " with original PAF Gibson humbuckers.
Bet it is silent as a graveyard in the same room.
........ Phil
C
CS
U¿ytkownik "Phil Allison said:
Ok if i am an idiot and you know better then you must be smart enough to
eplain to an idiot why "That scenario PROVES the direct opposite" ?
My guitar (in my room) is ~30 dB quieter than my cousin's (genuine) strat.
Do you realize that there is no humbucker on this planet that will buck 100%
of hum ?
