Anyone heard of radiometal for transformer core?

[MGH]

Thanks Yvesm and LinuksGuru for the info on radiometal, which appears to be commercially available as 45% nickel. I think the 55% radiometal AudioNote uses is their own formulation, as I can't find any information on it except on the AN site.

[BudP]

Does Audio Note have their own foundry? The only commercial provider for medium % nickle core in the US is Carpenter. They sell to all of the die stamping and annealing companies, such as Magnetics Inc, EMF, Temple Steel and possibly others. The material from Carpenter varies from 48% to 51% nickle content. Just as in Commercial E/I manganese/ iron core the permeability is +- 25%. I currently have a bout 9 pounds of +25% perm 50% category nickle lams, in 3/4" center leg. They are a pain in the *ss to design for because the high perm distorts all capacitance measurements and in a non linear fashion at that. Coils that measure just fine with nominal perm material have wildly different capacitance with this stuff. Makes no particular sense to me either!

Bud

[DF96]

Originally Posted by BudP

The only commercial provider for medium % nickle core in the US is Carpenter.

I think Audio Note are in the UK, so presumably source their materials in Europe?

[MGH]

Can anyone explain how bombarding nickel with radioactive isotope have any effect on low level signal sensitivity? I mean somebody thought of doing this in the past for some purpose. Military use? Long transmission line use by phone companies?

[BudP]

Ah DF then all bet's are off. Former Eastern Block nations were involved in many projects unsuitable to the US and western European "Green" policies. They have my sympathy for what it's worth.

Am still not sure that 55% nickle is in any way better than 48,49 or 50%. Even 80% does not have higher permeability, but it does ramp up sooner. I have attached a perm curve for 48 & 80% to show this difference. The major problem with higher nickle content is that it must be annealed to what is known as square anneal. Zero DC mag current tolerance, and even with a gap you get incremental saturation and zero tolerance for saturation in any event. Goes from low distortion to 100% with a few millivolts too many.

As for bombarding nickle alloys with radiation from unknown isotopes, not a clue.

Bud

[LinuksGuru]

Originally Posted by MGH

Can anyone explain how bombarding nickel with radioactive isotope have any effect on low level signal sensitivity? I mean somebody thought of doing this in the past for some purpose. Military use? Long transmission line use by phone companies?

AudioNote is not the company with the most outrageous claims.
If you look for products from the same league. you can find quantum music purifiers, magic liquids and power cords, etc.
One should not look for any scientific / engineering / logical explanation of all that staff, this is mixture of marketing crap and blatant charlatanry.

[marce]

Marketing
The one department in every company that has no base in reality.in commercial products you often get marketing wars between different companies, after one such event the data sheet for a £130 product stated it could be used up to 1km from the master unit (the only problem being you needed £4000 of good quality beldon cable).

[cyclecamper]

Originally Posted by Yvesm

Found in RDH4 :

Good reading, thanks.

[Sch3mat1c]

If it's actually radiated, I can't imagine it would do any good. Radiation induces crystal defects which, like work hardening and impurities, makes the metal hard and brittle, and increases hysteresis losses. Annealing undoes most of these failings, hence mu metal and permalloy are at their best when fully annealed after being formed to their final shape.

Not that any of this matters anyway, if the effective permeability is over 1000 or so, you won't even know the core is there, at least until it saturates. Which means you won't notice any difference between *any* material until the full-volume bass drum hits.

And I mean anyone at all, whether casual, experienced or "audiophile", none will observe a difference in a double-blind test (ooh, the naughty word).

And if you don't want to count double-blind tests, then consider this, it also will perform as well as gold-plated laminations (which will have slightly higher eddy current losses, but not enough to notice). The difference being, at least with a gold plated transformer you have something to point at and say "my money makes it sound better!".

Tim

[jlsem]

Radiometal is simply 45% nickel alloy with copper or manganese added to increase resistance.

The effect of irradiation in the form of neutron bombardment on Radiometal raises its coercivity, lowers its maximum permeability, and reduces its saturation density. All of these things would appear to degrade the performance of a soft magnetic material. However, irradiation will also demagnetize nickel alloys giving a temporary but significant rise in initial permeability, which would be a good thing. For a small signal transformer like a moving coil cartridge step-up, demagnetization may be a worthwhile treatment, but I would personally opt for a more conventional method.

Irradiation by fast electrons in a magnetic field causes 80% nickel alloys to form a square hysteresis loop at lower temperatures than conventional annealing in a magnetic field. Again, I can't see any advantage here since it appears to be a costlier alternative.

John