Interesting, but from past experience, the results may be just the opposite
a few months later because the source of the components may change over
time.
The components of fluorescent fixtures consists of
The ballast - which is usually outsourced by the fixture manufacturer.
Ballast types vary - GE, Universal, Advance, and several other Ballast
makers sell to fixture manufacturers.
The sockets - usually made by Leviton or Eagle or Rodale - but there are
others.
The lamp (the fluorescent lamp). Usually are not provided by the fixture
manufacturer. Made by Phillips, GE, Sylvania, etc.
Some even have a 'starter'.
--I expect the ballast is the critical component - some are magnetic, some
are electronic - its probably the culprit


"News Features" wrote in message
...
I'm not sure if this is the right newsgroup for this, but I wanted to get
this information out there to help others.

Our electrician arrived with brand new fluorescent under-counter lights to
install in our new kitchen. I told him, "Hey, I already bought lights at
Expo! Can you simply install mine?"

For some reason he was very reluctant to install my lights. He insisted
that his were just as good, if not better, than mine. I didn't have a
strong preference so I let him install his lights.

When it was finally dark, my wife turned them on to get the full effect.
To my horror, the AM radio two rooms away was instantly and completely
obliterated with RFI. I ran out to the shack and confirmed noise all the
way up to 20 meters.

The next day, I removed his lights and installed mine, and I was extremely
pleased to note not a hint of noise on any frequency, unless the receiver
was 6 inches from the light.

His lights: Bright Inch by Elite Lighting.

Mine: SlimLite by Hera Lighting.
http://www.heralighting.com/hera/slimlite.html

They cost more, but they're worth every penny.

Regards,

Al W6LX

"Hal Rosser" wrote in message
...
--I expect the ballast is the critical component - some are magnetic, some
are electronic - its probably the culprit

Hello, Hal.

I suspected the electronic ballast in the "bad" light myself. They both use
electronic ballasts. Perhaps it's an unfiltered ballast in the "bad" light
or something like that. They both are supposedly made in the USofA so I
can't blame it on the Chinese tendency to eliminate unnecessary items like
filter capacitors to save 18 cents of the cost.

I hope you're wrong about the two lights switching places; somehow, I can't
imagine the "bad" light gradually becoming RFI-quiet over time... by what
mechanism could that happen?

I am judging the lights as they are... one is noisy, the other is quiet. It
is somewhat amazing that we are trying to make excuses for this situation
rather than accept that some lights are noisy and some are quiet! :^)

"News Features" wrote in message
news:lDumk.35103

I hope you're wrong about the two lights switching places; somehow, I
can't
imagine the "bad" light gradually becoming RFI-quiet over time... by what
mechanism could that happen?

I can think of one, but it's obscure and unlikely. Some electrolytic
capacitors must be "formed" by application of voltage to develop their
rated characteristics. (However, it's applied DC that usually does such
forming, and I think all production flourescent lamps run exclusively on
AC.) If an unformed cap were installed as a filter and if it were later
formed by applied voltage, that is the mechanism that occurs to me.

Contradictions welcome.

No No - when I mentioned changing places - I'm talking about the brands at
an arbitrary time in the future, should the same experiment be run at
another time in the future - using new fixtures at the time *(not the ones
you have now)* I would not expect the noisy one to fix itself, and I
wouldn't expect the quiet one to become noisy out of the blue.
sorry if I was unclear.

"News Features" wrote in message
...

"Hal Rosser" wrote in message
...
--I expect the ballast is the critical component - some are magnetic,
some are electronic - its probably the culprit

Hello, Hal.

I suspected the electronic ballast in the "bad" light myself. They both
use electronic ballasts. Perhaps it's an unfiltered ballast in the "bad"
light or something like that. They both are supposedly made in the USofA
so I can't blame it on the Chinese tendency to eliminate unnecessary items
like filter capacitors to save 18 cents of the cost.

I hope you're wrong about the two lights switching places; somehow, I
can't imagine the "bad" light gradually becoming RFI-quiet over time... by
what mechanism could that happen?

I am judging the lights as they are... one is noisy, the other is quiet.
It is somewhat amazing that we are trying to make excuses for this
situation rather than accept that some lights are noisy and some are
quiet! :^)

On Wed, 6 Aug 2008 22:38:20 -0400, "Hal Rosser"
wrote:

Interesting, but from past experience, the results may be just the opposite
a few months later because the source of the components may change over
time.
The components of fluorescent fixtures consists of
The ballast - which is usually outsourced by the fixture manufacturer.
Ballast types vary - GE, Universal, Advance, and several other Ballast
makers sell to fixture manufacturers.
The sockets - usually made by Leviton or Eagle or Rodale - but there are
others.
The lamp (the fluorescent lamp). Usually are not provided by the fixture
manufacturer. Made by Phillips, GE, Sylvania, etc.
Some even have a 'starter'.
--I expect the ballast is the critical component - some are magnetic, some
are electronic - its probably the culprit

I'm curious, what does the ballast do? I see it referred to on light
fixtures I've installed, but I've never quite figured out what it is.

bob
k5qwg




"News Features" wrote in message
...
I'm not sure if this is the right newsgroup for this, but I wanted to get
this information out there to help others.

Our electrician arrived with brand new fluorescent under-counter lights to
install in our new kitchen. I told him, "Hey, I already bought lights at
Expo! Can you simply install mine?"

For some reason he was very reluctant to install my lights. He insisted
that his were just as good, if not better, than mine. I didn't have a
strong preference so I let him install his lights.

When it was finally dark, my wife turned them on to get the full effect.
To my horror, the AM radio two rooms away was instantly and completely
obliterated with RFI. I ran out to the shack and confirmed noise all the
way up to 20 meters.

The next day, I removed his lights and installed mine, and I was extremely
pleased to note not a hint of noise on any frequency, unless the receiver
was 6 inches from the light.

His lights: Bright Inch by Elite Lighting.

Mine: SlimLite by Hera Lighting.
http://www.heralighting.com/hera/slimlite.html

They cost more, but they're worth every penny.

Regards,

Al W6LX

http://home.howstuffworks.com/fluorescent-lamp6.htm

Bob Miller wrote:
On Wed, 6 Aug 2008 22:38:20 -0400, "Hal Rosser"
wrote:

Interesting, but from past experience, the results may be just the opposite
a few months later because the source of the components may change over
time.
The components of fluorescent fixtures consists of
The ballast - which is usually outsourced by the fixture manufacturer.
Ballast types vary - GE, Universal, Advance, and several other Ballast
makers sell to fixture manufacturers.
The sockets - usually made by Leviton or Eagle or Rodale - but there are
others.
The lamp (the fluorescent lamp). Usually are not provided by the fixture
manufacturer. Made by Phillips, GE, Sylvania, etc.
Some even have a 'starter'.
--I expect the ballast is the critical component - some are magnetic, some
are electronic - its probably the culprit

I'm curious, what does the ballast do? I see it referred to on light
fixtures I've installed, but I've never quite figured out what it is.




All these bulb work by passing current through an ionized gas. The
forward voltage drop across the tube goes down as current goes up ( a
so-called negative resistance characteristic). If there weren't
something to limit the current, it would rise to the point of
destruction. You could use a resistor, but it's lossy. All you need is
some impedance, so an (almost lossless) inductor works fine. That is,
hook up an inductor with a reactance of 100 ohms to a 100Vac source, and
you'll get a current of 1 Amp, but no power is consumed because the
current is out of phase with the voltage.

You could also use a constant current regulator to do the same thing.
If the regulator is a variable duty cycle switcher, then the loss can be
quite low. That's what's in the electronic ballast... essentially a
constant current source.

In practice, there's some more aspects to getting a fluorescent lamp
started.. you have to ionize the gas inside, which you can do either
with a filament (gets things rolling, and once current is flowing, the
current in the gas keeps it ionized) or with a high voltage pulse (like
a flash tube).. (this is the difference between the "thermal starter"
where you see the tube glow reddish at the ends at the beginning, and
the "rapid start" types)

(This is also why fluorescent lamps are dimmer/harder to start in cold
temperatures..)



Where the term "ballast" came from, I don't know.

"Jim Lux" wrote in message
...

snip

Where the term "ballast" came from, I don't know.

Possibly from the meaning "imparting stability." A ship's or boat's
ballast does that. Ballast around railroad ties does that. Ballast in a
hot air balloon does that.

A ballast tube in the filament circuit of a certain radio of my
acquaintance, the R-390A/URR, stabilizes the filament current for two
oscillator tubes, the VFO and the BFO.

I'm curious, what does the ballast do? I see it referred to on light
fixtures I've installed, but I've never quite figured out what it is.

bob
k5qwg


The ballast serves two purposes -
it 'strikes the arc' (starts the current flow)
and it
Limits the current flow
(otherwise current would spike and destroy the fluorescent lamp)

The efficiency of a fluorescent fixture is dependent partly on the ballast -
and usually - electronic ballasts are the more efficient of the two. HPF
ballasts usually use less current than a standard ballast.
You Compare fixture efficiency by comparing the ballast specifications
assuming they use the same lamp.
The web site that John Smith posted a link to explains it pretty well.

In article ,
"Hal Rosser" wrote:

Interesting, but from past experience, the results may be just the opposite
a few months later because the source of the components may change over
time.
The components of fluorescent fixtures consists of
The ballast - which is usually outsourced by the fixture manufacturer.
Ballast types vary - GE, Universal, Advance, and several other Ballast
makers sell to fixture manufacturers.
The sockets - usually made by Leviton or Eagle or Rodale - but there are
others.
The lamp (the fluorescent lamp). Usually are not provided by the fixture
manufacturer. Made by Phillips, GE, Sylvania, etc.
Some even have a 'starter'.
--I expect the ballast is the critical component - some are magnetic, some
are electronic - its probably the culprit

GE makes an RFI Filter that can be added to standard 4 Ft Tube Ballasts,
and that will eliminate MOST MF/HF Fixture Interference. I have been
using them in Alaska for years.

--
Bruce in alaska
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