YSHIELD MCF5 | Magnetic field shielding film |--> good stuff??

[rock soderstrom]

Hi folks,

what do you think of this product? The manufacturer gives quite promising data. Does anyone have any real-world experience with it?

Intended use would be the shielding of sensitive circuit parts, (signal)transformer and transducers against NF and HF interference such as transformer magnetic induced hum and mobile phone net crosstalk .

English text and data in the article description

https://www.ebay.de/itm/17414960355...JAm6ueKTrO&var=&widget_ver=artemis&media=COPY

 

[gyraf]

Magnetic shielding properties are a function of magnetic softness (~magnetic conductivity) and thickness. Nothing else. And you don't get much softer than e.g. mu-matal.

So, although such material will do some shielding, it's not much in those dimensions

Electrostatic shielding, on the other hand, is easily available - but does not require esoteric materials.

 

[rock soderstrom]

So, although such material will do some shielding, it's not much in those dimensions

Manufacturer says:

• Attenuation LF magnetic field: 30 dB (97 %)
• Attenuation HF: 70 dB

if true, that would be good for one layer of such a thin material. For two layer it should be 40dB over the whole audio spectrum. Not bad.

And it seems that this material is way better to work with, you can bend and cut it.

"In comparison with MUMETALL® our MCF5 has many advantages: MUMETALL® is soft and sensitive, on bending, to shocks and on processing it looses the attenuation very fast. MCF5 stays flexible but hard even at small bending radii. The attenuation remains constant even at high mechanical stress. MCF5 can easily be cut with scissors."

Too good to be true?

 

[gyraf]

I very much doubt those specs translates to usable behavior IRL- e.g. it clearly depends on how you specify "LF", on how much signal you want to shield for (density) and so on. Magnetic shielding works by diverting, not stopping like electrostatic - so you simply need room for the field lines to follow. Invoking the magic "cobalt" without further explanation smells like BS

When I worked at our local MR-center doing setups for fMRi, we tried everything we could get our hands on in this direction. The very-best materials you can get (the mu-metal family) are some 4-5times better than soft iron - meaning that 0.5mm of this magic material more-or-less equals 2mm of humble soft iron. Which can off course be significant, but mainly if you really are in a crammed design and have nowhere to expand

/Jakob E.

edit: A friend of mine - tona.dk - that does moving-coil step-up transformers for hifi and was fighting this sort of problem took the consequence of this and made a soft-iron stack for keeping interference out:

 

[rock soderstrom]

Thanks Jakob for your input

 

[jensenmann]

I´ve used this foil once when I had a Manley VariMu on the bench. The owner, a mastering guy, asked me to lower it´s noisefloor since he felt it to be unsufficient. Amongst other measures I´ve wrapped the trannies with this foil. It gave me 2dB less noise.

 

[rock soderstrom]

I´ve used this foil once when I had a Manley VariMu on the bench. The owner, a mastering guy, asked me to lower it´s noisefloor since he felt it to be unsufficient. Amongst other measures I´ve wrapped the trannies with this foil. It gave me 2dB less noise.

On the one hand, 2dB noise reduction doesn't sound so bad in a professional device which should be very optimized in itself. On the other hand, I don't know the Manley unit and the other measures you took, so it's a bit hard for me to classify.

Would you rate it as positive or more homeopathic subtle?

Thank you Jens for your feedback

 

[dmp]

Old post, but I have bought and used this adhesive backed mu-metal:
https://www.nooelec.com/store/cool-stuff/mumetal-half.htmlI think this is the real deal. In testing, it reduced magnetic induced hum from the power transformer to preamp (transformers / chokes).
It is not stiff enough on it's own, but works well if you already have or can fashion some kind of metal can over a transformer or choke (steel or aluminum).
Since bending or cutting can reduce the effectiveness, do so with care. An good audio transformer with a shield is going to be better than something that can be DIYed because it is shaped and then annealed (heat treated). When DIYed the shaping reduces the effectiveness.
When shaping, make the mu-metal a continuous loop, because as gyraf says "Magnetic shielding works by diverting, not stopping"

The Yshield MCF5 has a high stated permeability (25-100k) and probably works pretty comparably to mumetal. I don't smell BS in their description (they have a stand alone website). mu metal has a permeability of 80-100k so might be slightly better.

The MCF5 however is 0.02mm thick while the mu metal above is 0.10 mm thick. However in some of DaveP's tests I think he found thicker layers were less effective than multiple separate layers.

 

[Tubetec]

Lining a steel toroid can with this might help , you want nested layers insulated from each other but still making ground contact at one point.
small gaps should be avoided .
Id start with a metal can and end and then use one of the heavy L shaped brackets to mount it up in the far corner of the chassis away from the sensitive components like the input transformer , now you have a good solid base to add the thin mu metal lining , but you also have several layers of steel in the way of magnetic flux trying to escape in the direction of your circuits.

 

[rock soderstrom]

Old post, but I have bought and used this adhesive backed mu-metal:
https://www.nooelec.com/store/cool-stuff/mumetal-half.htmlI think this is the real deal. In testing, it reduced magnetic induced hum from the power transformer to preamp (transformers / chokes).
It is not stiff enough on it's own, but works well if you already have or can fashion some kind of metal can over a transformer or choke (steel or aluminum).
Since bending or cutting can reduce the effectiveness, do so with care. An good audio transformer with a shield is going to be better than something that can be DIYed because it is shaped and then annealed (heat treated). When DIYed the shaping reduces the effectiveness.
When shaping, make the mu-metal a continuous loop, because as gyraf says "Magnetic shielding works by diverting, not stopping"

The Yshield MCF5 has a high stated permeability (25-100k) and probably works pretty comparably to mumetal. I don't smell BS in their description (they have a stand alone website). mu metal has a permeability of 80-100k so might be slightly better.

The MCF5 however is 0.02mm thick while the mu metal above is 0.10 mm thick. However in some of DaveP's tests I think he found thicker layers were less effective than multiple separate layers.

Thanks for the feedback. I am still interested in the matter, I will give MCF5 material a try in the near future.