I'm posting this here because:
1. The problem is occurring in a wooddorking shop.
2. There are a lot of computer dorks who are also woodorkers, who
hang out here.
I'm working at my desk at the commercial wooddorking shop that I have
come to work at and every once in awhile ( every two minutes) my
computer screen jumps and is unreadable for a second.
It is my understanding that the shop next door is a metal shop and has
a welder (of an unidentified type) that is against the wall that
separates us.
I have not gone next door to see what kind of equipment they are
running but the screen jump is very annoying.
Is the problem more likely to be a power problem or an RF problem?
How can I resolve the problem?
I have seen power strips that include RF filters and sell for about 50
bucks. I don't like getting into my pocket any more than the next guy
but would do so if I could have some expectation of relief.
I look at spreadsheets all day, now and they are hard to read when
they jump around.
Thanks.
Thomas J. Watson-Cabinetmaker (ret)
Real Email is: tjwatson1ATcomcastDOTnet
Website: http://home.comcast.net/~tjwatson1
Look for something with the 2 minute cycle. A high intensity dicharge
lamp( mecury vapor) has both the current draw and electronics to cause
this type of problem. If the bulb or the electronics is bad you will
have a startup cycle problem, that if I remember takes about two minutes
to cycle thru. Some electronic ballast flourecents may cause a problem
but there is not the current draw to cause a large RF burst.
Tom Watson wrote:
> I'm posting this here because:
>
> 1. The problem is occurring in a wooddorking shop.
> 2. There are a lot of computer dorks who are also woodorkers, who
> hang out here.
>
> I'm working at my desk at the commercial wooddorking shop that I have
> come to work at and every once in awhile ( every two minutes) my
> computer screen jumps and is unreadable for a second.
>
> It is my understanding that the shop next door is a metal shop and has
> a welder (of an unidentified type) that is against the wall that
> separates us.
>
> I have not gone next door to see what kind of equipment they are
> running but the screen jump is very annoying.
>
> Is the problem more likely to be a power problem or an RF problem?
>
> How can I resolve the problem?
>
> I have seen power strips that include RF filters and sell for about 50
> bucks. I don't like getting into my pocket any more than the next guy
> but would do so if I could have some expectation of relief.
>
> I look at spreadsheets all day, now and they are hard to read when
> they jump around.
>
> Thanks.
>
>
>
>
> Thomas J. Watson-Cabinetmaker (ret)
> Real Email is: tjwatson1ATcomcastDOTnet
> Website: http://home.comcast.net/~tjwatson1
On Mon, 19 Jan 2004 20:46:24 -0500, Tom Watson wrote:
> I'm posting this here because:
>
> 1. The problem is occurring in a wooddorking shop.
> 2. There are a lot of computer dorks who are also woodorkers, who
> hang out here.
>
> I'm working at my desk at the commercial wooddorking shop that I have
> come to work at and every once in awhile ( every two minutes) my
> computer screen jumps and is unreadable for a second.
Aliens
-Doug
Larry Jaques <novalidaddress@di\/ersify.com> wrote in message news:<[email protected]>...
> On Tue, 20 Jan 2004 15:00:06 GMT, "Randy Chapman"
> <[email protected]> brought forth from the murky depths:
>
> >> > How can I resolve the problem?
> >
> >$300 for an LCD monitor?
>
> For CAD/graphics work? I'd rather be buried alive
> in an ant hill. (But that just might solve the RF
> problem.)
>
Gentleman may differ. I bought 2 syncmaster 213Ts just to do CAD/graphics...
Tom,
As an aid to diagnosing the problem try rotating the monitor in the
horizontal plane for a while. The disturbance you are seeing, if caused
by a magnetic field is going to be a function of the orientation of the
CRT. Consequently it should change markedly if you rotate the monitor
90 degrees. If it doesn't change then its a good guess it isn't
magnetic in origin.
RB
Tom Watson wrote:
> I'm posting this here because:
>
> 1. The problem is occurring in a wooddorking shop.
> 2. There are a lot of computer dorks who are also woodorkers, who
> hang out here.
>
> I'm working at my desk at the commercial wooddorking shop that I have
> come to work at and every once in awhile ( every two minutes) my
> computer screen jumps and is unreadable for a second.
>
> It is my understanding that the shop next door is a metal shop and has
> a welder (of an unidentified type) that is against the wall that
> separates us.
>
> I have not gone next door to see what kind of equipment they are
> running but the screen jump is very annoying.
>
> Is the problem more likely to be a power problem or an RF problem?
>
> How can I resolve the problem?
>
> I have seen power strips that include RF filters and sell for about 50
> bucks. I don't like getting into my pocket any more than the next guy
> but would do so if I could have some expectation of relief.
>
> I look at spreadsheets all day, now and they are hard to read when
> they jump around.
>
> Thanks.
>
>
>
>
> Thomas J. Watson-Cabinetmaker (ret)
> Real Email is: tjwatson1ATcomcastDOTnet
> Website: http://home.comcast.net/~tjwatson1
Best answer. It's both, really, though power, especially in the sticks, is
the way to attack it. UPS for isolation, and let the alarm ring. My rural
Co-Op is scrimping as new places are added, and though the drops do not go
below 105V, the UPS on this computer is set for a % drop alarm.
Most welders fire and charge capacitors, which is the RF source.
"Wilson Lamb" <[email protected]> wrote in message
news:[email protected]...
> Borrow a small UPS and put your PC and monitor on it.
> Wilson
Shunt capacitor on the power supply?
Me too.
"Doug Winterburn" <[email protected]> wrote in message
news:[email protected]...
> On Mon, 19 Jan 2004 20:46:24 -0500, Tom Watson wrote:
>
> > I'm working at my desk at the commercial wooddorking shop that I have
> > come to work at and every once in awhile ( every two minutes) my
> > computer screen jumps and is unreadable for a second.
> >
>
> I had a monitor that exhitited similar symptoms for about two months, then
> it died. The new monitor works fine.
>
> -Doug
Comprehension level of a Shrub critic.
"Larry Jaques" <novalidaddress@di\/ersify.com> wrote in message
news:[email protected]...
> On Wed, 21 Jan 2004 07:18:14 +0000, [email protected]
> (Robert Bonomi) brought forth from the murky depths:
>
> >"Reading counts", Larry. With extra points for reading comprehension.
> >The _facts_:
> >
> > 1) He didn't say it _lasts_ two minutes, he said it *occurs* every two
> > minutes or so. The =duration=, according to the original poster
> > is about *one*second*. That _is_ accurately characterized as a
> > 'momentary sag'.
>
> <blush> I reread it and found my initial comprehension somewhere
> around that of your average Shrub supporter. Sorry.
In article <[email protected]>,
Larry Jaques <novalidaddress@di\/ersify.com> wrote:
>On Wed, 21 Jan 2004 07:18:14 +0000, [email protected]
>(Robert Bonomi) brought forth from the murky depths:
>
>>Not necessarily a true CV supply. Those are *really* nice, but *heavy*, and
>>_expensive_. Tripp, and some other people make units with multiple-tap
>
>This was one from a hospital. CV/Iso, the whole bit. About 200 lbs.
Sounds like it was made by SOLA, and rated for about 300 watts. Nah, at
200 lbs, more like 450 watts. The 300 watt unit is only about 140 lbs.
makes one h*ll of a door-stop and/or toe-stubber when not hooked up. <grin>
>
>
>>>What, no tinfoil hat for the monitor? <g>
>>
>>Nope. Too much heat being generated. Good way to 'cook' the electronics
>
>Speaking of reading comprehension, what's that <g> behind
>my silly suggestion?
A self-assigned letter grade, one level _worse_ than an <f>, maybe? *snicker*
BTW, I've _seen_ people do *exactly* that. With results ranging from 'merely'
frying the monitor, to tripping the overhead water.
Sometimes one has to treat the frivolous question seriously, to prevent
the "*doesn't* know any better" third party from implementing it.
>>However, I =did= solve an _RFI_ problem in an office that way once. Completely
>>wrapped the affected piece of machinery in Renoylds Wrap (heavy duty, _wide_),
>>and ran a wire to the center screw on the duplex outlet that it was plugged
>>into. People in the office thought I was *crazy*... until the fix _worked_,
>>that is. :)
>
>Pulling crazy stunts is great fun, wot?
I learned a few things from a _real_ master. He was chief engineer for one
of the big network TV stations in town, and volunteered for theater dept
support at the H.S. I attended. One day, there was a problem with an
audio feed -- he grabs two _shielded_ audio cables. lines 'em up together
for about 3 feet, ties a big overhand knot with the paired cables, and throws
it on the wooden stage floor. *Without* plugging the connectors on
the cables together. The truly scary thing is _IT_WORKED_! To this day,
I don't understand the 'how' or 'why' of it. Even though I, a few months
later, did exactly the same thing, to deal with the same problem at the
same place. And it worked for me, too.
"Tom Watson" <[email protected]> wrote in message
news:[email protected]...
>
>
> I'm posting this here because:
>
> 2. There are a lot of computer dorks who are also woodorkers, who
> hang out here.
Ahem - Senior Computer Dork, if you please...
> How can I resolve the problem?
Get a hobby?
You ever considered wooddorking?
[ There are two 'D's, aren't there? ]
In article <[email protected]>,
Tom Watson <[email protected]> wrote:
>On Tue, 20 Jan 2004 01:19:17 -0500, Greg G. wrote:
>
>>Tom Watson said:
>
>>>Here's what I don't understand. If the power surge coming form thief
>>>side is great enough, can it induce a surge in my wiring, even though
>>>we are not hard-wired together?
>>
>
>
>>Eventually, you ARE hard-wired together. It is *supposed* to be at a
>>point where this doesn't occur, but shit happens... ;-) That's why I
>>said "you <may> have problems not easily resolved."
>>
>
>
>Good point. An interesting observation is that all of the guys who
>are on CRT's in offices that share the wall with the metal
>fabricator's shop have "jumping screen".
>
>The guys who are on laptops, in the same offices, do not have the
>problem.
>
>The guys on the other side of the hall from the offices that share the
>fabricator's wall, do not have the problem. The problem seems to be
>specific to CRT's and seems to be related to proximity to the wall
>shared with the fabricator's shop.
Given all that, the _real_ test is to temporarily run an extension cord
from the _same_ outlet that one of the machines "on the other side of the
hall", uses over to where -your- machine is. And see if _your_ screen
still jumps when your neighbor's do.
Laptop LED/LCD/whatever displays are radically different in design than
CRD displays, and are not subject to the same kinds of ideosyncratic
behavior on -voltage- irregularities. Laptops essentially run off their
batteries _all_ the time, with the line cord functioning as a battery
charger. In effect, they're on a "full-time" UPS.
The machines across the hall could be on a different phase of the power
distribution into the building. And the 'sag' is specific to the phase
the machines 'next to the wall' are powered from.
If you can describe "exactly what it looks like" _when_ the 'screen jump'
occurs, I may be able to provide better guesses. Does the picture pull
in from the sides, so you see black at the right/left edges. possibly
pulling in more in the middle, than at top/bottom (sort-of hour-glass like)
and acts like a TV with the vertical hold out, probably "rolling" from the
top down?
Or does the picture get 'twisted', and colors go "funny", with what _should_
be the same color showing as different colors at different parts of the
screen? If you pull up something that makes the entire screen pure white,
do you notice that the white is not the 'same shade of white' at all parts
of the screen. i.e.,ill-defined areas of pale pastel colors?
The former is symptomatic of power problems.
The latter is symptomatic of magnetic impulse problems.
RFI (Radio Frequency Interference) typically shows up as an imposed 'pattern'
on blocks of solid colors (herringbone/moire type stuff), and 'fuzzy' edges
to things that should be sharp. Sometimes noticed as 'jitter' in a _horizontal_
direction.
On Mon, 19 Jan 2004 20:46:24 -0500, Tom Watson <[email protected]>
brought forth from the murky depths:
>I'm posting this here because:
>
>1. The problem is occurring in a wooddorking shop.
>2. There are a lot of computer dorks who are also woodorkers, who
>hang out here.
>
>I'm working at my desk at the commercial wooddorking shop that I have
>come to work at and every once in awhile ( every two minutes) my
>computer screen jumps and is unreadable for a second.
>
>It is my understanding that the shop next door is a metal shop and has
>a welder (of an unidentified type) that is against the wall that
>separates us.
>I have not gone next door to see what kind of equipment they are
>running but the screen jump is very annoying.
>
>Is the problem more likely to be a power problem or an RF problem?
RF. All of the new MIG welders have an RF circuit for managing
the arc.
>How can I resolve the problem?
Either call Lincoln and/or Hobart to see if they have any suggestions
or get your neighboring welding shop to do so. Giving them the model
number will help. They would be more likely to know what is causing it
and how to fix it.
>I have seen power strips that include RF filters and sell for about 50
>bucks. I don't like getting into my pocket any more than the next guy
>but would do so if I could have some expectation of relief.
Possibly. But covering your offices in a Faraday cage would be better.
;) http://www.physics.gla.ac.uk/~kskeldon/PubSci/exhibits/E3/
>I look at spreadsheets all day, now and they are hard to read when
>they jump around.
Graphics programs are like that, too. I had a girlfriend dust my
office once, and for 2 days I couldn't figure out what had caused
the jittery monitor problem. I finally figured out that she had
set the electric clock on the shelf above the monitor and the 60hz
motor magnetics were dropping down almost a foot to wreak visual
havoc upon said monitor.
BTW, it was great talking to you on the phone last night. I had
wondered where you had disappeared to. I seldom include an accent
in my visualization of Wreckers so yours surprised me a bit. You
appear to be a book fan, reading as much or more than I do. (I
keyed on that more from your posts than from our discussion.)
P.S: Until it's resolved, taking a break from the spreadsheets is
a great way to pass the time while they weld.
P.P.S: Go over there yourself. Get to know them. Welders are very
handy pals to have around. ;)
-
Every day above ground is a Good Day(tm).
-----------
http://diversify.com Website Application Programming
In article <[email protected]>,
Larry Jaques <novalidaddress@di\/ersify.com> wrote:
>On Tue, 20 Jan 2004 23:17:53 +0000, [email protected]
>(Robert Bonomi) brought forth from the murky depths:
>
>>Another possibility is "none of the above". <grin>
>>
>>The most likely culprit _is_ power. A momentary 'sag' when some
>>big piece of equipment is turned on, "somewhere in the vicinity.
>
>Umm, a 2-minute long "momentary sag", Robert? Besides, computers
>operate on +-5v and 12v power. Their power supplies can handle
>pretty big sags and filthy power before turning off or acting up.
"Reading counts", Larry. With extra points for reading comprehension.
The _facts_:
1) He didn't say it _lasts_ two minutes, he said it *occurs* every two
minutes or so. The =duration=, according to the original poster
is about *one*second*. That _is_ accurately characterized as a
'momentary sag'.
2) The problem is with the *monitor*, not the computer. The high-voltage
'drive' sections of the CRT are step-up transformer, and voltage-
multiplier section, -driven; from the power line, There _may_ be a 5V
supply for some of the solid-state components. (some units I've seen
and/or worked on had solid-state components that ran off voltage in
the circa 50V range.) There almost assuredly is -not- a 12V supply
_in_the_monitor_. 12V is used in computers for (a) RS-232 serial-port
driver chips, and (b) motors of assorted sorts, primarily disk-drives of
various types, but also some fans.
3) I'll agree "dirty power" is usually -not- a problem. For CRT's,
however, 'sags' *are* an issue. For *safety* reasons, there is usually
very little 'carrying time' in the HV sections. You _want_ the HV
to die *quickly* if/when the mains power is removed.
>>Assuming it's a 'power' problem, you need a 'line stabilizer', AKA 'line
>>conditioner'. A typical "Un-interruptible Power supply" will _not_ help
>>with this issue -- they are a 'stand-by' device that cuts in -only- when
>>the power fails completely.
>
>Right, constant voltage supply. I left one in CA when I moved.
>Too damned heavy!
Not necessarily a true CV supply. Those are *really* nice, but *heavy*, and
_expensive_. Tripp, and some other people make units with multiple-tap
buck/boost transformers coupled with voltage-sensitive relay switching.
They're relatively fast acting (i.e., within a power cycle or two.) and
cut in/out some fixed stages of buck/boost to 'normalize' the output
voltage. _Much_ less expensive than a CV transformer of similar AMPacity,
e.g. an 1800 watt 'stabilizer' is less than US$100, new. And weighs in at
less than 5 lbs. A _clear_ 'winner', when you can tolerate 'limited'
fluctuations in the mains power. I've got a unit that will hold the
output voltage to within the range of 115-125V, for input voltages ranging
from 85V to 145V. Doesn't help _at_all_ if the power fails completely,
but eliminates any of the other 'surprises'.
>>If it _is_ a magnetic field problem, then the effective cure is _move_
>>the affected stuff further away from the source.
>
>What, no tinfoil hat for the monitor? <g>
Nope. Too much heat being generated. Good way to 'cook' the electronics
inside. Tinfoil is of very limited effectiveness against magnetic pulse
anyway -- more effective against RFI. Magnetic pulse strength is inversely
proportional to "between distance squared, and distance cubed". Moving
further away is -much- simpler/cheaper/more-effective than trying to
construct something to block/attenuate the pulse.
However, I =did= solve an _RFI_ problem in an office that way once. Completely
wrapped the affected piece of machinery in Renoylds Wrap (heavy duty, _wide_),
and ran a wire to the center screw on the duplex outlet that it was plugged
into. People in the office thought I was *crazy*... until the fix _worked_,
that is. :)
On Tue, 20 Jan 2004 23:17:53 +0000, [email protected]
(Robert Bonomi) brought forth from the murky depths:
>Another possibility is "none of the above". <grin>
>
>The most likely culprit _is_ power. A momentary 'sag' when some
>big piece of equipment is turned on, "somewhere in the vicinity.
Umm, a 2-minute long "momentary sag", Robert? Besides, computers
operate on +-5v and 12v power. Their power supplies can handle
pretty big sags and filthy power before turning off or acting up.
>Assuming it's a 'power' problem, you need a 'line stabilizer', AKA 'line
>conditioner'. A typical "Un-interruptible Power supply" will _not_ help
>with this issue -- they are a 'stand-by' device that cuts in -only- when
>the power fails completely.
Right, constant voltage supply. I left one in CA when I moved.
Too damned heavy!
>If it _is_ a magnetic field problem, then the effective cure is _move_
>the affected stuff further away from the source.
What, no tinfoil hat for the monitor? <g>
-
Every day above ground is a Good Day(tm).
-----------
http://diversify.com Website Application Programming
In article <[email protected]>,
[email protected] <[email protected]> wrote:
>On Mon, 19 Jan 2004 20:46:24 -0500, Tom Watson <[email protected]>
>wrote:
>
>>I'm posting this here because:
>>
>>1. The problem is occurring in a wooddorking shop.
>>2. There are a lot of computer dorks who are also woodorkers, who
>>hang out here.
>>
>>I'm working at my desk at the commercial wooddorking shop that I have
>>come to work at and every once in awhile ( every two minutes) my
>>computer screen jumps and is unreadable for a second.
>>
>>It is my understanding that the shop next door is a metal shop and has
>>a welder (of an unidentified type) that is against the wall that
>>separates us.
>>
>>I have not gone next door to see what kind of equipment they are
>>running but the screen jump is very annoying.
>>
>>Is the problem more likely to be a power problem or an RF problem?
>>
>>How can I resolve the problem?
>>
>>I have seen power strips that include RF filters and sell for about 50
>>bucks. I don't like getting into my pocket any more than the next guy
>>but would do so if I could have some expectation of relief.
>>
>>I look at spreadsheets all day, now and they are hard to read when
>>they jump around.
>>
>>Thanks.
>>
>>
>>
>>
>>Thomas J. Watson-Cabinetmaker (ret)
>>Real Email is: tjwatson1ATcomcastDOTnet
>>Website: http://home.comcast.net/~tjwatson1
>
>do you by chance use an UPS ???? if not that may help if its power
>related. the UPS will keep power to the puter and the monitor somewhat
>constant if indeed power is the problem. skeez
*IF* and _only_ if you buy one of the high-priced "full-time" UPS systems.
The typical 'hobbiest'/'small office' UPS is a "standby" system - the
battery power kicks in only if the line power fails _completely_.
On Mon, 19 Jan 2004 20:46:24 -0500, Tom Watson wrote:
> I'm working at my desk at the commercial wooddorking shop that I have
> come to work at and every once in awhile ( every two minutes) my
> computer screen jumps and is unreadable for a second.
>
I had a monitor that exhitited similar symptoms for about two months, then
it died. The new monitor works fine.
-Doug
On Mon, 19 Jan 2004 20:46:24 -0500, Tom Watson <[email protected]>
wrote:
>I'm posting this here because:
>
>1. The problem is occurring in a wooddorking shop.
>2. There are a lot of computer dorks who are also woodorkers, who
>hang out here.
>
>I'm working at my desk at the commercial wooddorking shop that I have
>come to work at and every once in awhile ( every two minutes) my
>computer screen jumps and is unreadable for a second.
>
>It is my understanding that the shop next door is a metal shop and has
>a welder (of an unidentified type) that is against the wall that
>separates us.
>
>I have not gone next door to see what kind of equipment they are
>running but the screen jump is very annoying.
>
>Is the problem more likely to be a power problem or an RF problem?
>
>How can I resolve the problem?
>
>I have seen power strips that include RF filters and sell for about 50
>bucks. I don't like getting into my pocket any more than the next guy
>but would do so if I could have some expectation of relief.
>
>I look at spreadsheets all day, now and they are hard to read when
>they jump around.
>
>Thanks.
>
>
>
>
>Thomas J. Watson-Cabinetmaker (ret)
>Real Email is: tjwatson1ATcomcastDOTnet
>Website: http://home.comcast.net/~tjwatson1
do you by chance use an UPS ???? if not that may help if its power
related. the UPS will keep power to the puter and the monitor somewhat
constant if indeed power is the problem. skeez
Hi Tom,
Difficult problem to guess at, so lets throw some logic into it. Pardon the
endless questions ... I think you'll see where I'm going here.
If this is the only computer in your shop, pop your head next door and see
if they have any computers, and if they are having the same problem. If you
have other computers in your shop, are they showing this problem where they
currently reside. If you can, move another computer to your work area
(unplug all your stuff, plug the replacement in exactly, and observe).
Try another monitor for a short while on your computer. A failing component
would explain the cyclic nature of the interference much better than pretty
much anything in the other shop (unless they're running an automated spot
welder all day).
Does the monitor make any noise when the screen wipes out? Does the picture
get all twisted like when you hit the degaussing button? Does the monitor
have this problem after the metal shop has shut down for the day/weekend? Do
you shut the monitor off at night? If so, does the problem show up
immediately after you turn the monitor on in the morning?
Take an AM radio and tune between stations. Set the radio next to the
monitor and listen for any increased noise when the monitor starts its
jumping routine. If you can hear the interference ... and it is cyclic, shut
your computer down and see if the noise is still there (and still cyclic).
It takes a LOT of current to mess with a monitor. I had one CRT within 3
feet of a pair of cables connected to a high current battery discharge
tester ... nominal 1800 amps would cause the whole video display to appear
like it was being pulled and twisted from the back (a terrible wedgie to be
sure). A defective battery that was only producing 700 amps didn't even
ripple the screen. We switched to an LCD monitor and never saw another
issue.
If nothing else, pull the workstation a couple feet away from the wall and
observe any differences.
Plug an incandescent lamp into the same outlet strip as your monitor ...
does it flicker along with the monitor?
Plug your entire computer into a drop cord that is fed from another breaker
away from the ajoining shop wall.
***
I really don't know how to call this one ... so if you can fill in any of
the blanks above, it will help resolve this.
Regards,
Rick
"Tom Watson" <[email protected]> wrote in message
news:[email protected]...
> I'm posting this here because:
>
<Interesting monitor problem story snipped>
There are so many possibilities for this it is not possible to answer.
Rick, in a previos post in this thread gave some good troubleshooting advice.
I'll just add my $0.02 worth...
Unless the welder or whatever industrial device is cycling at two minute intervals,
just ignore it. If it is cycling every two minutes, like in some production line,
see below regarding power supplies. However, other equipment would probably show
some signs if this were happening.
If there were that much EMI there sould be significant health effects around the building
by now,
(and a great law suit). So let's ignore that for now.
The most likely culprits are the computer and the monitor.
1) The computer.
a) Is there a CD/DVD sitting close to the monitor?
Is your CD/DVD or similar being accessed every two minutes?
Perhaps for license verification or graphics/clip art/music refresh? (App
controlled)
b) Power supply issues.
b1) Power supply not operating properly.
b2) Input line voltage dropping below reliable operating range of the power
supply.
This could effect other systems in your PC but the more obvious impact
could be on the video display adaptor. Some of these can become tempramental
when their operating tolerances are not met.
## One possible cause could be momentary spikes from the welder, depending on
how/where the branch curcuit was installed.
Other
2) The Monitor.
a) Bad tube or internal controller. System componets often fail in a cyclic manner
before
fully quitting. (i.e. It could be a degaus curcuit is firing due to a failing
contoller.
b) Line voltage dropping below reliable operating range of the power supply.
## One possible cause could be momentary spikes from the welder, depending on
how/where the branch curcuit was installed.
I think that more than my two cents worth, and its worth every cent!
Good Luck,
Myx
Whoa Larry. Just picked up a 19" ViewSonic to replace a 19" (really 18")
CRT that just died a week ago. I've had dual monitors hooked up for several
years now and when I stretch a CAD drawing across both screens, the LCD is
much easier to look at in comparison.
Maybe your experience was with an older model / technology. The model I
have isn't top of the line (double the cost too) but sure is better than my
analog CRT's.
Bob S.
"Larry Jaques" <novalidaddress@di\/ersify.com> wrote in message
news:[email protected]...
> On Tue, 20 Jan 2004 15:00:06 GMT, "Randy Chapman"
> <[email protected]> brought forth from the murky depths:
>
> >> > How can I resolve the problem?
> >
> >$300 for an LCD monitor?
>
> For CAD/graphics work? I'd rather be buried alive
> in an ant hill. (But that just might solve the RF
> problem.)
>
> -
> Every day above ground is a Good Day(tm).
> -----------
> http://diversify.com Website Application Programming
"Tom Watson" <[email protected]> wrote in message
news:[email protected]...
> On Mon, 19 Jan 2004 21:11:33 -0500, Greg G. wrote:
>
>
> >If it IS power related, and their wiring is separated from your
> >building, you have problems not easily resolved.
>
>
> Here's what I don't understand. If the power surge coming form thief
> side is great enough, can it induce a surge in my wiring, even though
> we are not hard-wired together?
>
>
>
> Thomas J. Watson-Cabinetmaker (ret)
> Real Email is: tjwatson1ATcomcastDOTnet
> Website: http://home.comcast.net/~tjwatson1
Again, I don't think it's power-related, but to answer your question,
through the magic of mutual inductance, a current on their side could induce
a current in your wiring. The effect would be most pronounced if you had an
electrical circuit running parallel and in close proximity to one of theirs
that carried a large load. Honestly, I don't know the magnitude of the
current that it could induce and I'm disinclined to look it up at this late
hour.
todd
Borrow a small UPS and put your PC and monitor on it.
Wilson
"Tom Watson" <[email protected]> wrote in message
news:[email protected]...
> I'm posting this here because:
>
> 1. The problem is occurring in a wooddorking shop.
> 2. There are a lot of computer dorks who are also woodorkers, who
> hang out here.
>
> I'm working at my desk at the commercial wooddorking shop that I have
> come to work at and every once in awhile ( every two minutes) my
> computer screen jumps and is unreadable for a second.
>
> It is my understanding that the shop next door is a metal shop and has
> a welder (of an unidentified type) that is against the wall that
> separates us.
>
> I have not gone next door to see what kind of equipment they are
> running but the screen jump is very annoying.
>
> Is the problem more likely to be a power problem or an RF problem?
>
> How can I resolve the problem?
>
> I have seen power strips that include RF filters and sell for about 50
> bucks. I don't like getting into my pocket any more than the next guy
> but would do so if I could have some expectation of relief.
>
> I look at spreadsheets all day, now and they are hard to read when
> they jump around.
>
> Thanks.
>
>
>
>
> Thomas J. Watson-Cabinetmaker (ret)
> Real Email is: tjwatson1ATcomcastDOTnet
> Website: http://home.comcast.net/~tjwatson1
Tom,
Rick gave some excellent troubleshooting advice.
Let me add one more thing. The video card in
the computer could have an intermittant fault too.
Art
"Rick" <[email protected]> wrote in message
news:[email protected]...
> Hi Tom,
>
> Difficult problem to guess at, so lets throw some logic into it. Pardon the
> endless questions ... I think you'll see where I'm going here.
>
> If this is the only computer in your shop, pop your head next door and see
> if they have any computers, and if they are having the same problem. If you
> have other computers in your shop, are they showing this problem where they
> currently reside. If you can, move another computer to your work area
> (unplug all your stuff, plug the replacement in exactly, and observe).
>
> Try another monitor for a short while on your computer. A failing component
> would explain the cyclic nature of the interference much better than pretty
> much anything in the other shop (unless they're running an automated spot
> welder all day).
>
> Does the monitor make any noise when the screen wipes out? Does the picture
> get all twisted like when you hit the degaussing button? Does the monitor
> have this problem after the metal shop has shut down for the day/weekend? Do
> you shut the monitor off at night? If so, does the problem show up
> immediately after you turn the monitor on in the morning?
>
> Take an AM radio and tune between stations. Set the radio next to the
> monitor and listen for any increased noise when the monitor starts its
> jumping routine. If you can hear the interference ... and it is cyclic, shut
> your computer down and see if the noise is still there (and still cyclic).
>
> It takes a LOT of current to mess with a monitor. I had one CRT within 3
> feet of a pair of cables connected to a high current battery discharge
> tester ... nominal 1800 amps would cause the whole video display to appear
> like it was being pulled and twisted from the back (a terrible wedgie to be
> sure). A defective battery that was only producing 700 amps didn't even
> ripple the screen. We switched to an LCD monitor and never saw another
> issue.
>
> If nothing else, pull the workstation a couple feet away from the wall and
> observe any differences.
>
> Plug an incandescent lamp into the same outlet strip as your monitor ...
> does it flicker along with the monitor?
>
> Plug your entire computer into a drop cord that is fed from another breaker
> away from the ajoining shop wall.
>
> ***
>
> I really don't know how to call this one ... so if you can fill in any of
> the blanks above, it will help resolve this.
>
> Regards,
>
> Rick
>
>
>
>
>
>
It could be either EMI or a power surge. I'm thinking EMI
because of the welding equipment. If you have and UPS unit
or know of a friend who has an UPS (uninterruptible power
supply) w/ a surge suppressor the unit should still supply power
without interruption during a power spike or drain. EMI is a much
more complex problem. requires a lot of bonding, shielding, and
the like Been dealing with it for years on ships and I'm still not sure
how the theory works on all the measures we take to reduce it.
I do know that if we key up a handheld radio in a room w/ a
computer in it that the screen will jump. Occasionally the screens
on monitors and TV's will have a green hue to them and we have
to degauss them because of the effects of EMI (electromagnetic
interference). So this could be another indicator (a soldering gun
can sometimes act as a degausser). Anyway my first course of action
would be to run my computer off and UPS without it plugged into the
outlet and see if the screen jumps when someone fires up the welder.
With the computer running off battery power you should not see the
effects of a power spike/drain with the welder in use. If the problem does
occur then your dealing with EMI and the solution will most likely
be more troublesome (and expensive) than the problem.
Joey in Chesapeake
"Tom Watson" <[email protected]> wrote in message
news:[email protected]...
> I'm posting this here because:
>
> 1. The problem is occurring in a wooddorking shop.
> 2. There are a lot of computer dorks who are also woodorkers, who
> hang out here.
>
> I'm working at my desk at the commercial wooddorking shop that I have
> come to work at and every once in awhile ( every two minutes) my
> computer screen jumps and is unreadable for a second.
>
> It is my understanding that the shop next door is a metal shop and has
> a welder (of an unidentified type) that is against the wall that
> separates us.
>
> I have not gone next door to see what kind of equipment they are
> running but the screen jump is very annoying.
>
> Is the problem more likely to be a power problem or an RF problem?
>
> How can I resolve the problem?
>
> I have seen power strips that include RF filters and sell for about 50
> bucks. I don't like getting into my pocket any more than the next guy
> but would do so if I could have some expectation of relief.
>
> I look at spreadsheets all day, now and they are hard to read when
> they jump around.
>
> Thanks.
>
>
>
>
> Thomas J. Watson-Cabinetmaker (ret)
> Real Email is: tjwatson1ATcomcastDOTnet
> Website: http://home.comcast.net/~tjwatson1
On Tue, 20 Jan 2004 01:19:17 -0500, Greg G. wrote:
>Tom Watson said:
>>Here's what I don't understand. If the power surge coming form thief
>>side is great enough, can it induce a surge in my wiring, even though
>>we are not hard-wired together?
>
>Eventually, you ARE hard-wired together. It is *supposed* to be at a
>point where this doesn't occur, but shit happens... ;-) That's why I
>said "you <may> have problems not easily resolved."
>
Good point. An interesting observation is that all of the guys who
are on CRT's in offices that share the wall with the metal
fabricator's shop have "jumping screen".
The guys who are on laptops, in the same offices, do not have the
problem.
The guys on the other side of the hall from the offices that share the
fabricator's wall, do not have the problem. The problem seems to be
specific to CRT's and seems to be related to proximity to the wall
shared with the fabricator's shop.
The good news is that our company is building new offices and I have
my name in to get one as far away as possible from the metal
fabricator's space.
Thanks for the help.
Thomas J. Watson-Cabinetmaker (ret)
Real Email is: tjwatson1ATcomcastDOTnet
Website: http://home.comcast.net/~tjwatson1
On Tue, 20 Jan 2004 17:38:18 -0500, Silvan
<[email protected]> brought forth from the murky depths:
>Larry Jaques wrote:
>
>> BTW, it was great talking to you on the phone last night. I had
>> wondered where you had disappeared to. I seldom include an accent
>> in my visualization of Wreckers so yours surprised me a bit. You
>
>Oooh, oooh, what kind of accent does Tom have?
GnuYawkish/PennsylTuckyish, I reckon.
-
Every day above ground is a Good Day(tm).
-----------
http://diversify.com Website Application Programming
"Tom Watson" <[email protected]> wrote in message
news:[email protected]...
> I'm posting this here because:
>
> 1. The problem is occurring in a wooddorking shop.
> 2. There are a lot of computer dorks who are also woodorkers, who
> hang out here.
>
> I'm working at my desk at the commercial wooddorking shop that I have
> come to work at and every once in awhile ( every two minutes) my
> computer screen jumps and is unreadable for a second.
>
> It is my understanding that the shop next door is a metal shop and has
> a welder (of an unidentified type) that is against the wall that
> separates us.
>
> I have not gone next door to see what kind of equipment they are
> running but the screen jump is very annoying.
>
> Is the problem more likely to be a power problem or an RF problem?
>
> How can I resolve the problem?
>
> I have seen power strips that include RF filters and sell for about 50
> bucks. I don't like getting into my pocket any more than the next guy
> but would do so if I could have some expectation of relief.
>
> I look at spreadsheets all day, now and they are hard to read when
> they jump around.
>
> Thanks.
>
>
>
>
> Thomas J. Watson-Cabinetmaker (ret)
> Real Email is: tjwatson1ATcomcastDOTnet
> Website: http://home.comcast.net/~tjwatson1
As others have said, it's hard to tell for sure, but my vote is for a
magnetic field problem induced by the large current from the welder. I had
a user once whose monitor was giving a "wavy" display. I went into the cube
on the other side of the wall from her monitor and found a small desk fan.
I turned the fan off and presto, no more interference. If a little fan like
that can create enough of a magnetif field to cause her monitor problems,
you can imagine what a welder would do. But I've got good news. I just
saved a load of money by switching to GEICO. Also, magnetic fields
dissipate by the inverse square of the distance from the source, so if you
can move your monitor far enough away from the wall, you might eliminate the
problem. The bad news of magnetic fields is that they're famously difficult
to shield. As an alternative, you could switch to an LCD as another poster
pointed out.
todd
In article <[email protected]>,
[email protected] (Robert Bonomi) writes:
> [email protected] <[email protected]> wrote:
>>On Mon, 19 Jan 2004 20:46:24 -0500, Tom Watson <[email protected]>
>>wrote:
>>>I'm working at my desk at the commercial wooddorking shop that I have
>>>come to work at and every once in awhile ( every two minutes) my
>>>computer screen jumps and is unreadable for a second.
>>do you by chance use an UPS ???? if not that may help if its power
>>related. the UPS will keep power to the puter and the monitor somewhat
>>constant if indeed power is the problem. skeez
> *IF* and _only_ if you buy one of the high-priced "full-time" UPS systems.
> The typical 'hobbiest'/'small office' UPS is a "standby" system - the
> battery power kicks in only if the line power fails _completely_.
A good UPS with voltage regulation isn't that expensive.
That said, one rarely if ever plugs peripherals like monitors
or printers into them. Their main purpose is to save data
(by not fscking up the file system on the HDD). Plugging
a monitor and/or printer into the UPS will reduce the
time it can power the computer while on the battery.
OBWW: I'm making a small shelf (out of wood) for a little
DVD player in my daughter's room. I'm worried about stray
electrical/magnetic fields harming the finish, and the
Flexner book (Bible, O'Deen) says nothing about how shellac
can protect against this. Would lining the shelf with lead be
the best option?
--
Jeff Thunder
Dept. of Mathematical Sciences
Northern Illinois Univ.
jthunder at math dot niu dot edu
On Tue, 20 Jan 2004 01:41:28 GMT, Doug Winterburn
<[email protected]> wrote:
>Aliens
>
>-Doug
I gotchyur aliens right here for ya, Winterburn. (this is where the
smiley face would go , if I knew how to make them).
Ah, well...
Thomas J. Watson-Cabinetmaker (ret)
Real Email is: tjwatson1ATcomcastDOTnet
Website: http://home.comcast.net/~tjwatson1
In article <[email protected]>,
Tom Watson <[email protected]> wrote:
>I'm posting this here because:
>
>1. The problem is occurring in a wooddorking shop.
>2. There are a lot of computer dorks who are also woodorkers, who
>hang out here.
>
>I'm working at my desk at the commercial wooddorking shop that I have
>come to work at and every once in awhile ( every two minutes) my
>computer screen jumps and is unreadable for a second.
>
>It is my understanding that the shop next door is a metal shop and has
>a welder (of an unidentified type) that is against the wall that
>separates us.
>
>I have not gone next door to see what kind of equipment they are
>running but the screen jump is very annoying.
>
>Is the problem more likely to be a power problem or an RF problem?
Another possibility is "none of the above". <grin>
The most likely culprit _is_ power. A momentary 'sag' when some
big piece of equipment is turned on, "somewhere in the vicinity.
Second possibility is that the welder -- *IF* it is electric arc (of some form)
and used intermittently -- is throwing a large _magnetic_ field when
energized, and that this is fouling the screen. If the piece of equipment
happens to be an electric "spot welder", it could create the described
effects.
>How can I resolve the problem?
FIRST THING is to identify the causative factor(s). See if there's a
different circuit available, that you can plug the computer into. Try
moving to different location in the room, etc.
Assuming it's a 'power' problem, you need a 'line stabilizer', AKA 'line
conditioner'. A typical "Un-interruptible Power supply" will _not_ help
with this issue -- they are a 'stand-by' device that cuts in -only- when
the power fails completely.
If it _is_ a magnetic field problem, then the effective cure is _move_
the affected stuff further away from the source.
>I have seen power strips that include RF filters and sell for about 50
>bucks. I don't like getting into my pocket any more than the next guy
>but would do so if I could have some expectation of relief.
>
>I look at spreadsheets all day, now and they are hard to read when
>they jump around.
>
>Thanks.
>
>
>
>
>Thomas J. Watson-Cabinetmaker (ret)
>Real Email is: tjwatson1ATcomcastDOTnet
>Website: http://home.comcast.net/~tjwatson1
On Mon, 19 Jan 2004 21:25:53 -0500, Tom Watson wrote:
> On Tue, 20 Jan 2004 01:41:28 GMT, Doug Winterburn
> <[email protected]> wrote:
>
>>Aliens
>>
>>-Doug
>
>
> I gotchyur aliens right here for ya, Winterburn. (this is where the
> smiley face would go , if I knew how to make them).
>
> Ah, well...
Oh, I forgot to mention - I just bought one of those really 'spensive HF
mig welders for $99. Hope the damn thing works for welding up the angle
iron base for the charcoal Barbie :-)
-Doug
On Wed, 21 Jan 2004 07:18:14 +0000, [email protected]
(Robert Bonomi) brought forth from the murky depths:
>"Reading counts", Larry. With extra points for reading comprehension.
>The _facts_:
>
> 1) He didn't say it _lasts_ two minutes, he said it *occurs* every two
> minutes or so. The =duration=, according to the original poster
> is about *one*second*. That _is_ accurately characterized as a
> 'momentary sag'.
<blush> I reread it and found my initial comprehension somewhere
around that of your average Shrub supporter. Sorry.
>Not necessarily a true CV supply. Those are *really* nice, but *heavy*, and
>_expensive_. Tripp, and some other people make units with multiple-tap
This was one from a hospital. CV/Iso, the whole bit. About 200 lbs.
>>What, no tinfoil hat for the monitor? <g>
>
>Nope. Too much heat being generated. Good way to 'cook' the electronics
Speaking of reading comprehension, what's that <g> behind
my silly suggestion?
>However, I =did= solve an _RFI_ problem in an office that way once. Completely
>wrapped the affected piece of machinery in Renoylds Wrap (heavy duty, _wide_),
>and ran a wire to the center screw on the duplex outlet that it was plugged
>into. People in the office thought I was *crazy*... until the fix _worked_,
>that is. :)
Pulling crazy stunts is great fun, wot?
--== May The Angst Be With You! ==--
-Yoda, on a bad day
--
http://diversify.com Ending Your Web Page Angst.
On Tue, 20 Jan 2004 15:00:06 GMT, "Randy Chapman"
<[email protected]> brought forth from the murky depths:
>> > How can I resolve the problem?
>
>$300 for an LCD monitor?
For CAD/graphics work? I'd rather be buried alive
in an ant hill. (But that just might solve the RF
problem.)
-
Every day above ground is a Good Day(tm).
-----------
http://diversify.com Website Application Programming
Tom,
Since you did not mention overhead lights dimming or the computer's UPS
kicking in, I would guess that it is RF. From the effect you describe on
the monitor to be caused by power there would have to be serious brown outs
How to check ? Move the comptuer -- use the same outlet via extension
cord and move the computer accross the room. The RF effects will diminish
with distance but power effects will travel with you (via the extension
cord)
Cheers
Eric
"Tom Watson" <[email protected]> wrote in message
news:[email protected]...
> I'm posting this here because:
>
> 1. The problem is occurring in a wooddorking shop.
> 2. There are a lot of computer dorks who are also woodorkers, who
> hang out here.
>
> I'm working at my desk at the commercial wooddorking shop that I have
> come to work at and every once in awhile ( every two minutes) my
> computer screen jumps and is unreadable for a second.
>
> It is my understanding that the shop next door is a metal shop and has
> a welder (of an unidentified type) that is against the wall that
> separates us.
>
> I have not gone next door to see what kind of equipment they are
> running but the screen jump is very annoying.
>
> Is the problem more likely to be a power problem or an RF problem?
>
> How can I resolve the problem?
>
> I have seen power strips that include RF filters and sell for about 50
> bucks. I don't like getting into my pocket any more than the next guy
> but would do so if I could have some expectation of relief.
>
> I look at spreadsheets all day, now and they are hard to read when
> they jump around.
>
> Thanks.
>
>
>
>
> Thomas J. Watson-Cabinetmaker (ret)
> Real Email is: tjwatson1ATcomcastDOTnet
> Website: http://home.comcast.net/~tjwatson1
On 22 Jan 2004 13:44:28 GMT, [email protected] (Jeffrey Thunder)
wrote:
>OBWW: I'm making a small shelf (out of wood) for a little
>DVD player in my daughter's room. I'm worried about stray
>electrical/magnetic fields harming the finish, and the
>Flexner book (Bible, O'Deen) says nothing about how shellac
>can protect against this. Would lining the shelf with lead be
>the best option?
the problem with this is that over time the lead will become
radioactive, posing a threat to your daughter's health. Sure, it might
take 10,000 years to reach a measureable level, but why take chances?
Tom Watson said:
>On Mon, 19 Jan 2004 21:11:33 -0500, Greg G. wrote:
>
>
>>If it IS power related, and their wiring is separated from your
>>building, you have problems not easily resolved.
>
>
>Here's what I don't understand. If the power surge coming form thief
>side is great enough, can it induce a surge in my wiring, even though
>we are not hard-wired together?
Eventually, you ARE hard-wired together. It is *supposed* to be at a
point where this doesn't occur, but shit happens... ;-) That's why I
said "you <may> have problems not easily resolved."
For instance, if you are out in the sticks, and have a long, shared
feed wire between the line transformer and your respective businesses,
they could be superimposing surges onto your AC lines.
I am willing to bet it is electro-magnetic interference, however.
I have a degaussing coil (which is an open air electromagnet used to
remove magnetic fields from the shadow mask in a CRT) that will affect
a computer CRT tube from 5 feet away. Walls don't influence its
effect, unless they are solid steel. It doesn't draw anywhere as much
power as a big welder transformer, but you get the idea...
Additionally, all newer monitors have what is known as a switched-mode
power supply, as do computers themselves. These things convert AC to
DC, then chop it into ~25kHz pulses used to drive the conversion
transformer to derive the voltages actually used by the monitor's
electronics. Pulse Width Modulation (PWM) is used to regulate the
voltages to the desired levels, depending on load. These things are
sometimes susceptible to hash on the AC line, although the better
units are not. (I repair monitors, among other things...)
Monitors are pretty heavily shielded against emitting RF energy, and
this also shields them somewhat against incoming RF as well.
I have a few ideas for you, however. Get a really long extension
cord, and run between a suspected unaffected outlet and your system.
If the problem remains, it probably isn't power related.
Move the computer system away from the suspicious welder. Magnetic
fields drop precipitously with distance. If the problem goes away,
it's probably magnetic fields affecting the monitor.
You could also have a failing monitor, I am assuming that it is O.K.
The electrolytic capacitors in the aforementioned PWM power supplies
go bad with age, and often cause jittery displays.
FWIW,
Greg G.
On Tue, 20 Jan 2004 03:39:38 GMT, Doug Winterburn
<[email protected]> wrote:
>
>Oh, I forgot to mention - I just bought one of those really 'spensive HF
>mig welders for $99. Hope the damn thing works for welding up the angle
>iron base for the charcoal Barbie :-)
>
>-Doug
I hope the sumbitch is from Whore Boor Freight and burns right the fug
up!
(now, here's where dem damned smiley's gotta go and I got no recourse
- sheesh.)
(ah, well, watson's tryin' ta be funny but don't have the resources.)
Thomas J. Watson-Cabinetmaker (ret)
Real Email is: tjwatson1ATcomcastDOTnet
Website: http://home.comcast.net/~tjwatson1
On Mon, 19 Jan 2004 21:11:33 -0500, Greg G. wrote:
>If it IS power related, and their wiring is separated from your
>building, you have problems not easily resolved.
Here's what I don't understand. If the power surge coming form thief
side is great enough, can it induce a surge in my wiring, even though
we are not hard-wired together?
Thomas J. Watson-Cabinetmaker (ret)
Real Email is: tjwatson1ATcomcastDOTnet
Website: http://home.comcast.net/~tjwatson1
Larry Jaques wrote:
> BTW, it was great talking to you on the phone last night. I had
> wondered where you had disappeared to. I seldom include an accent
> in my visualization of Wreckers so yours surprised me a bit. You
Oooh, oooh, what kind of accent does Tom have?
--
Michael McIntyre ---- Silvan <[email protected]>
Linux fanatic, and certified Geek; registered Linux user #243621
http://www.geocities.com/Paris/Rue/5407/
Tom Watson said:
>It is my understanding that the shop next door is a metal shop and has
>a welder (of an unidentified type) that is against the wall that
>separates us.
It is probably a magnetic field from the welder transformer which is
effecting the CRT, although it could be power related. I would move
my desk to the farthest wall in any event. Those huge magnetic fields
will give you brain cancer. ;-) You could try a LCD display, which
would not be effected.
If it IS power related, and their wiring is separated from your
building, you have problems not easily resolved.
In any event, distance is likely to be the only reasonable solution.
FWIW,
Greg G.
Tom,
My experience with an electric welder was a bit more dramatic and it was due
to RF. We were installing a satellite ground station out in Christmas
Valley Oregon and the FAA called us one day to tell us our satellite dish
was interfering with aircraft radio transmissions on their approach to Bend
Oregon. Huh?...Says we...it isn't even powered up yet!
Upon further investigation, we found that the install crew had the covers
off the generator/welder (trailer mounted puppy) to help keep it cool and it
was wiping out the aircraft frequencies as they flew overhead.... It was
probably wiping out the rest of the FM and HF bands to but we had the covers
put back on and the FAA was happy (as I sure a few pilots were also).
So, yes it could be RF, magnetic and power-line induced. Try moving the
computer and wearing tin foil hats to see if that helps...
Bob S.
"Tom Watson" <[email protected]> wrote in message
news:[email protected]...
> I'm posting this here because:
>
> 1. The problem is occurring in a wooddorking shop.
> 2. There are a lot of computer dorks who are also woodorkers, who
> hang out here.
>
> I'm working at my desk at the commercial wooddorking shop that I have
> come to work at and every once in awhile ( every two minutes) my
> computer screen jumps and is unreadable for a second.
>
> It is my understanding that the shop next door is a metal shop and has
> a welder (of an unidentified type) that is against the wall that
> separates us.
>
> I have not gone next door to see what kind of equipment they are
> running but the screen jump is very annoying.
>
> Is the problem more likely to be a power problem or an RF problem?
>
> How can I resolve the problem?
>
> I have seen power strips that include RF filters and sell for about 50
> bucks. I don't like getting into my pocket any more than the next guy
> but would do so if I could have some expectation of relief.
>
> I look at spreadsheets all day, now and they are hard to read when
> they jump around.
>
> Thanks.
>
>
>
>
> Thomas J. Watson-Cabinetmaker (ret)
> Real Email is: tjwatson1ATcomcastDOTnet
> Website: http://home.comcast.net/~tjwatson1
On Tue, 20 Jan 2004 01:41:28 GMT, Doug Winterburn
<[email protected]> brought forth from the murky depths:
>On Mon, 19 Jan 2004 20:46:24 -0500, Tom Watson wrote:
>
>> I'm posting this here because:
>>
>> 1. The problem is occurring in a wooddorking shop.
>> 2. There are a lot of computer dorks who are also woodorkers, who
>> hang out here.
>>
>> I'm working at my desk at the commercial wooddorking shop that I have
>> come to work at and every once in awhile ( every two minutes) my
>> computer screen jumps and is unreadable for a second.
>
>Aliens
SPANISH RFI? That's a new one, 'cept for the AM stations.
-
Every day above ground is a Good Day(tm).
-----------
http://diversify.com Website Application Programming
Crt's can be very much affected by power.
(A) Large power panels will drive certain models nuts.
(B) The welder will almost certainly create short bursts
that will make the monitor "jump".
You can two different things:
(a) Shield the wall
(b) Move away from any large power panel.
The strips will have little effect on the monitor.
Certain monitors are better protected than others.
Try a different monitor at the same location.
Tom Watson wrote:
> I'm posting this here because:
>
> 1. The problem is occurring in a wooddorking shop.
> 2. There are a lot of computer dorks who are also woodorkers, who
> hang out here.
>
> I'm working at my desk at the commercial wooddorking shop that I have
> come to work at and every once in awhile ( every two minutes) my
> computer screen jumps and is unreadable for a second.
>
> It is my understanding that the shop next door is a metal shop and has
> a welder (of an unidentified type) that is against the wall that
> separates us.
>
> I have not gone next door to see what kind of equipment they are
> running but the screen jump is very annoying.
>
> Is the problem more likely to be a power problem or an RF problem?
>
> How can I resolve the problem?
>
> I have seen power strips that include RF filters and sell for about 50
> bucks. I don't like getting into my pocket any more than the next guy
> but would do so if I could have some expectation of relief.
>
> I look at spreadsheets all day, now and they are hard to read when
> they jump around.
>
> Thanks.
>
>
>
>
> Thomas J. Watson-Cabinetmaker (ret)
> Real Email is: tjwatson1ATcomcastDOTnet
> Website: http://home.comcast.net/~tjwatson1
On Mon, 19 Jan 2004 22:51:20 -0500, Tom Watson <[email protected]>
wrote:
>On Mon, 19 Jan 2004 21:11:33 -0500, Greg G. wrote:
>
>
>>If it IS power related, and their wiring is separated from your
>>building, you have problems not easily resolved.
>
>
>Here's what I don't understand. If the power surge coming form thief
>side is great enough, can it induce a surge in my wiring, even though
>we are not hard-wired together?
>
you are hard wired together at some point- at the panel or all of the
way out at the pole... 'twould take quite a surge to jump that,
though...
Bridger <[email protected]> writes:
> On 22 Jan 2004 13:44:28 GMT, [email protected] (Jeffrey Thunder)
> wrote:
>
>>OBWW: I'm making a small shelf (out of wood) for a little
>>DVD player in my daughter's room. I'm worried about stray
>>electrical/magnetic fields harming the finish, and the
>>Flexner book (Bible, O'Deen) says nothing about how shellac
>>can protect against this. Would lining the shelf with lead be
>>the best option?
No. Lead is not a good conductor, neither for electrical current nor
for magnetic flux. You *could* use magneticaly soft iron, but if you
do not build a complete cage it does not do anything useful.
>
>
> the problem with this is that over time the lead will become
> radioactive, posing a threat to your daughter's health. Sure, it might
Why should the lead do so? From cosmics?
--
Dr. Juergen Hannappel http://lisa2.physik.uni-bonn.de/~hannappe
mailto:[email protected] Phone: +49 228 73 2447 FAX ... 7869
Physikalisches Institut der Uni Bonn Nussallee 12, D-53115 Bonn, Germany
CERN: Phone: +412276 76461 Fax: ..77930 Bat. 892-R-A13 CH-1211 Geneve 23