Materials that absorb RF energy

[Shadders]

Hi,

From the internet :

http://www.masttechnologies.com/rf-absorbers/

 

MR5 Low Frequency Absorbers
Low Frequency Absorbers provide high loss at sub-microwave frequencies. Low Frequency Absorbers are designed with shaped magnetic particles which exhibit high permeability at frequencies from 1 MHz to 3 GHz.

 

Without the statement of the material used in the Dark Matter product, difficult to ascertain its effectiveness and its properties.

 

If it contains a permeable material then it will effect those EM fields within its vicinity - but recall, flux density is a 1/(r^2) law so will only affect those "components" close.

 

Since it cannot act like a black hole/singularity - it will not be a sink for RF, but will only absorb those waves incident upon its surface and at its specific working frequencies.

 

Regards,

Shadders.

[Shadders]

3 hours ago, jabbr said:

Both Digi-Key and Mouser contain entire sections devoted to EMI absorbing products — easy to browse and read spec sheets... I’ve used “mu-metal” https://en.m.wikipedia.org/wiki/Mu-metal

 

These applications are everywhere ... easy to tinker with different materials/foams/sheets etc.

 

There are also gazillions of RF & EMI meters (which are probably junk) but I keep picturing @fas42 walking around someone’s listening room like Ghostbusters and applying various putties in different spots ...

 

See “ferrite” has a bad connotation for you so I think it’s pretty brilliant to rename it “Dark Matter”  Just think of the continued potential for the audiophile cable industry!

 

@wgscott: I have a new business proposition: water cooled AC power cables — interested? 

Hi,

If the product does contain permeable material, and hence creates an inductive load - if as per their suggestion, you place the product inside a piece of equipment, such as a power amplifier, i wonder if the inductive effect will create a significant phase change in the circuit to generate positive feedback and cause the power amplifier to oscillate........

 

Maybe that is why it has a change to equipment, just that the designers have not realised it ?

 

Regards,

Shadders.

[Speedskater]

Is someone designing a cell-phone?  Because that is one of the few places that a RF absorbing foam might be useful.

[barrows]

8 hours ago, mansr said:

Barrows says "Dark Matter is a passive device which damps RF energy fields" and that "it acts on RF energy which is present in its vicinity." The only logical interpretation of these statements is that it somehow sucks in the badness around it. The placement suggestions also seem to be based on such a notion. And then there's the negative ion nonsense.

 

I have no reason to doubt that these blocks do in fact contain some amount of RF absorbing material. After all, such things are readily available. I do, however, doubt that it is particularly effective deployed in this manner.

I have very clearly stated multiple times on the DM thread that it DOES NOT, lure, attract, or "suck in" anything.  It damps RF fields in its vicinity, by that I mean field energy which passes directly through it.

As I have stated on the DM thread multiple times, the placement of DM is very important to achieve effectiveness.

 

Please do not try and create controversy by first inferring something which has not been claimed, and then following with criticism of the product by saying it is impossible for it to "attract" or "lure" RF energy.

 

This works the same as an antenna, etc.  It couples with energy which is hitting/passing through it.  Just as an antenna does not "attract" RF energy/waves, neither does Dark Matter.

[barrows]

4 hours ago, Shadders said:

Without the statement of the material used in the Dark Matter product, difficult to ascertain its effectiveness and its properties.

Materials in Dark Matter are proprietary and will not be revealed.  There is no ferrite.  Suffice it to say that the materials involved are not really esoteric, and are well accepted by science to be able to couple with RF energy and convert some of it to heat.

 

There ia a much better way to access its effectiveness, try it.  In my experience looking at data sheets of various RF absorbing materials will not tell one if they will be effective for improving the sonics of one's system (unless perhaps one is an RF engineer and can precisely measure the RF field strengths/frequencies in and around components and then match the product to their needs on a purely technical basis).  No matter what, there will be some trial and error in any attempt at RF mitigation in a system context.

[Jud]

5 hours ago, Shadders said:

 

Since it cannot act like a black hole/singularity - it will not be a sink for RF, but will only absorb those waves incident upon its surface and at its specific working frequencies.

 

Yep, that's precisely what's been claimed.

[Shadders]

36 minutes ago, barrows said:

Materials in Dark Matter are proprietary and will not be revealed.  There is no ferrite.  Suffice it to say that the materials involved are not really esoteric, and are well accepted by science to be able to couple with RF energy and convert some of it to heat.

 

There ia a much better way to access its effectiveness, try it.  In my experience looking at data sheets of various RF absorbing materials will not tell one if they will be effective for improving the sonics of one's system (unless perhaps one is an RF engineer and can precisely measure the RF field strengths/frequencies in and around components and then match the product to their needs on a purely technical basis).  No matter what, there will be some trial and error in any attempt at RF mitigation in a system context.

Hi,

It may not contain ferrite, but it may have magnetically permeable material - hence increase inductance of the wire etc.

 

It is stated to convert some of the energy to heat - but not the percentage.

 

The text states "DM will be more effective in areas, and around wiring, carrying high currents, so the first place to try it is at the AC input of power conditioners feeding the entire system, or at the AC input of power amplifiers"

 

To reduce the RF energy - in high current wires - it will have to have an inductive property (permeable) - else it will only absorb the RF energy in its vicinity, and the RF energy will continue through the wire to the equipment, and the DM will have nil effect (which is not what is claimed).

 

It is stated that it will not conduct electricity - butt his could purely be due to the casing, not allowing the proprietary substance to be exposed at the surface.

 

As i indicated earlier - if the description is accurate, and it therefore is inductive, then i would not allow a customer to place it inside a power amplifier.

 

Regards,

Shadders.

[mansr]

1 hour ago, barrows said:

I have very clearly stated multiple times on the DM thread that it DOES NOT, lure, attract, or "suck in" anything.  It damps RF fields in its vicinity, by that I mean field energy which passes directly through it.

You seem to have a somewhat confused understanding of fields, waves, and energy, and the relationships between them.

[jabbr]

1 hour ago, barrows said:

Suffice it to say that the materials involved are not really esoteric, and are well accepted by science to be able to couple with RF energy and convert some of it to heat.

 

This description is precious. “couple with RF energy and convert some of it to heat” is the same as absorb yet seems to be more. It’s just physics, not mystics.

 

All the materials which absorb RF do this.

[Ralf11]

but it is more than mere absorption isn't it?  I mean in terms of the processing inside the material

 

of course, it sounds better too

 

 

[Ralf11]

Just to re-emphasize that this is a real world phenomena and not some Tice clock nonsense.

 

barrows says he is not making much profit on this and I think it is good to explore possible benefits

 

...

when used in a conscientiously applied program of double blind testing and regular professional care

[jabbr]

11 minutes ago, Ralf11 said:

but it is more than mere absorption isn't it?  I mean in terms of the processing inside the material

 

RF absorbing materials absorb RF just like black felt absorbs visible light. Both get warm.

 

https://en.m.wikipedia.org/wiki/Black-body_radiation

[barrows]

18 minutes ago, jabbr said:

.

Of course.  And no one has made any claims to the contrary.  I fail to understand why some posters are trying to stir some kind of controversy RE Dark Matter.  It is quite simple, and not mystical, or magical, and no mystical or magical claims have been made for it.

 

Indeed, I like the fact tat this thread exists as well, as exploring various options for mitigating RF (and perhaps other second order type of deleterious effects) is interesting to me, and perhaps to other audiophiles.  

[Ralf11]

4 minutes ago, jabbr said:

 

RF absorbing materials absorb RF just like black felt absorbs visible light. ...

 

I will disagree.  Felt absorbs radiation without the need for any included materials.  The photons are directly absorbed by the material itself.  RAM uses (AFAIK) something such as small balls or loops embedded in a matrix.  And the spatial properties of those 'items' are important too...

[mansr]

10 minutes ago, barrows said:

I fail to understand why some posters are trying to stir some kind of controversy RE Dark Matter.

Maybe because you keep making confused and contradictory claims about what it does.

[mansr]

7 minutes ago, Ralf11 said:

I will disagree.  Felt absorbs radiation without the need for any included materials.  The photons are directly absorbed by the material itself.  RAM uses (AFAIK) something such as small balls or loops embedded in a matrix.  And the spatial properties of those 'items' are important too...

It's the same thing. Because radar frequencies are much lower than those of light, the structures of the material need to be correspondingly larger.

[jabbr]

22 minutes ago, barrows said:

Of course.  And no one has made any claims to the contrary.  I fail to understand why some posters are trying to stir some kind of controversy RE Dark Matter.  It is quite simple, and not mystical, or magical, and no mystical or magical claims have been made for it

 

Correct. My OP says this. Some aspects of the description may appear to suggest otherwise which is why I wanted to explain how I see this — and using language of my choice.

 

I haven’t read anything from you that I don’t interpret as straightforward RF absorption or EMI absorption.

[jabbr]

12 minutes ago, Ralf11 said:

 

I will disagree.  Felt absorbs radiation without the need for any included materials.  The photons are directly absorbed by the material itself.  RAM uses (AFAIK) something such as small balls or loops embedded in a matrix.  And the spatial properties of those 'items' are important too...

 

Substitute : RF photons are directly absorbed by H2O itself without the need for any included materials ... or UV photons are directly absorbed by glass without the need for included materials.

 

The absorption of a photon by a material has to do with the physical chemical properties of the material.

[Ralf11]

with a photon, you are bumping things around in the outer valence shell; not so for RAM

 

at any rate, absorb would be ok

[mansr]

6 minutes ago, Ralf11 said:

with a photon, you are bumping things around in the outer valence shell; not so for RAM

You mean visible light photon. All EM waves are photons. The RF ones just don't have enough energy to mess with electrons.

[Ralf11]

yup

[fas42]

1 hour ago, barrows said:

Of course.  And no one has made any claims to the contrary.  I fail to understand why some posters are trying to stir some kind of controversy RE Dark Matter.  It is quite simple, and not mystical, or magical, and no mystical or magical claims have been made for it.

 

Indeed, I like the fact tat this thread exists as well, as exploring various options for mitigating RF (and perhaps other second order type of deleterious effects) is interesting to me, and perhaps to other audiophiles.  

 

There are people who are curious why SQ is affected by "strange things", and investigate - and then there are those who have decided that they have 'full control' over everything, using prescribed techniques. The latter are disturbed by the former, and attempt to make them figures of fun, etc - to mitigate their discomfort at the thought that perhaps the "other side" do have something of value ...

 

A rather good summary of matters is the Grounding and Shielding chapter, by Gerke and Kimmel, in the book Measurement, Instrumentation, and Sensors Handbook, by Webster. Just replace the word "industrial" throughout the text with "audio replay", to get a sense of a useful approach to take ...

[jabbr]

1 hour ago, Ralf11 said:

with a photon, you are bumping things around in the outer valence shell; not so for RAM

Indeed the effects of RF absorption by protons forms the basis of MRI imaging.

[Shadders]

11 hours ago, barrows said:

Of course.  And no one has made any claims to the contrary.  I fail to understand why some posters are trying to stir some kind of controversy RE Dark Matter.  It is quite simple, and not mystical, or magical, and no mystical or magical claims have been made for it.

 

Indeed, I like the fact tat this thread exists as well, as exploring various options for mitigating RF (and perhaps other second order type of deleterious effects) is interesting to me, and perhaps to other audiophiles.  

Hi,

The claims made lack definition.

 

Since the statement is that placing it near high current carrying wires to reduce RF is made, this would therefore mean for any useful reduction of RF along the conductor, that the substance must have permeability. Just like a ferrite ring.

 

If all it does is absorb an EM wave (no permeability) - with a specific bandwidth of frequencies, then it will have insignificant effect on the reduction of RF in the equipment enclosure, and nil effect of reducing RF in the conductor.

 

Regards,

Shadders.

[Solstice380]

13 hours ago, mansr said:

It's the same thing. Because radar frequencies are much lower than those of light, the structures of the material need to be correspondingly larger.

 

Correct.  The wavelengths absorbed will be dictated by the lattice structure if it’s an inorganic material, or the polymer chain bond length if organic.