Re: Looking for info on EMI/RFI attenuation on Furman ss-6b

[Guest guest]

Just to show that I'm not completely sitting on my butt. I found this

in a related product the M-10. Nothing on the ss-6b. But I'm guessing

it's similar. It's basicly low pass filtering. Now I just need to find

out what that does on an AC circuit and I'm sure I'll need to learn

something else to understand that " I call this a recursive problem

:-). I do have an idea of what a low pass filter does on audio so I'm

guessing its similar.

" RFI/EMI INTERFERENCE: Noise from RFI

(Radio Frequency Interference) or EMI (Electro

Magnetic Interference) involves lower voltages

and less energy than is found in spikes, but it is

continuous rather than transient in nature. It is

not likely to cause damage, but it can certainly

be annoying, producing static in audio circuits,

" snow " on video screens, or garbled data in

computers. Noise can be introduced into AC

lines by nearby radio transmitters, certain kinds

of lighting, electric motors, and other sources.

Because noise occurs at higher

frequencies than the 50 or 60 Hz AC line, it can

be effectively reduced through use of low-pass

filtering. "

>

> I was looking at a low cost temporary line filtering solution for a

> computer that I think has a dicey power supply. I was wondering if

> anyone had any idea of what the filtering was on this model (ss-6b).

> It's about $30. I know that their more expensive filters have " linear "

> filtering but I'm still learning what exactly this means. I couldn't

> find any info on Furman's web site.

>

> Thanks, Alan

>

[Guest guest]

> I know that their more expensive filters have " linear "

> filtering but I'm still learning what exactly this means. I couldn't

> find any info on Furman's web site.

I've got the more expensive Furman power strips with linear filtering.

They are definitely more tolerable to me than cheap power strips with

capacitors. They also reduce the noise readings on the Stetzerizer

meters on the surrounding outlets.

Furman claims that the cheap filters lower the lower frequencies, but

then may raise or cause spikes at some higher frequencies. " Linear "

filtering is supposed to not raise the higher frequencies or cause

spikes.

Marc

[Guest guest]

I know Stetzer filters draw current that is a distorted sine wave,

which indicates that the capacitor is acting in a nonlinear way.

A good quality capacitor would draw a sine wave.

It is easy to make a filter that will filter out frequencies around 10 MHz

or higher. It is much harder to filter down at 200 or 20 kHz, but that's

the range where a lot of switching power supplies operate.

Bill

On Wed, Sep 10, 2008 at 8:22 AM, Marc <marc@...> wrote:

> > I know that their more expensive filters have " linear "

> > filtering but I'm still learning what exactly this means. I couldn't

> > find any info on Furman's web site.

>

> I've got the more expensive Furman power strips with linear filtering.

> They are definitely more tolerable to me than cheap power strips with

> capacitors. They also reduce the noise readings on the Stetzerizer

> meters on the surrounding outlets.

>

> Furman claims that the cheap filters lower the lower frequencies, but

> then may raise or cause spikes at some higher frequencies. " Linear "

> filtering is supposed to not raise the higher frequencies or cause

> spikes.

>

> Marc

>

>

[Guest guest]

Thanks for the info. And of course they are way more expensive. But I

guess you get what you pay for. Money is starting to become an issue

for me... Sigh.

Thanks, Alan

>

> > I know that their more expensive filters have " linear "

> > filtering but I'm still learning what exactly this means. I couldn't

> > find any info on Furman's web site.

>

> I've got the more expensive Furman power strips with linear filtering.

> They are definitely more tolerable to me than cheap power strips with

> capacitors. They also reduce the noise readings on the Stetzerizer

> meters on the surrounding outlets.

>

> Furman claims that the cheap filters lower the lower frequencies, but

> then may raise or cause spikes at some higher frequencies. " Linear "

> filtering is supposed to not raise the higher frequencies or cause

> spikes.

>

> Marc

>

[Guest guest]

Hi ,

Is there a url for this. Is this accessible without a subscription.

I found an earlier post for a Nov 2007 issue in pdf. But I can't quite

decipher the pattern in the url. Unfortunately I only understand

English. So navigating the site is well, " challenging " .

I'm afraid I'm an American and ... you know... couldn't translate my

way out a paper bag :-)

> >>

> >> I was looking at a low cost temporary line filtering solution for a

> >> computer that I think has a dicey power supply. I was wondering if

> >> anyone had any idea of what the filtering was on this model (ss-6b).

> >> It's about $30. I know that their more expensive filters have

" linear "

> >> filtering but I'm still learning what exactly this means. I couldn't

> >> find any info on Furman's web site.

> >>

> >> Thanks, Alan

> >>

> >

> >

> >

> > ------------------------------------

> >

> >