JFE JNEX

Design and use of Chokes for PS, anode and filament use.
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PakProtector
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Joined: Wed May 04, 2005 2:36 am

JFE JNEX

Post by PakProtector »

This is quite interesting.

http://www.jfe-steel.co.jp/en/products/ ... index.html

cheers,
Douglas

did I mention I want some?
Question Authority, disobey it only after understanding it, and when absolutely required...
dave slagle
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Post by dave slagle »

i guess i have to ask how different another manufacturers .004 C-core would be under the exact same test conditions.

unfortunately they only compare a generic sheet steel of the same thickness and i am unclear how they do this. Did they use a ring sample, EI or other stamped lams or simple stamped I's to make a core?

dave
PakProtector
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Joined: Wed May 04, 2005 2:36 am

Post by PakProtector »

Hey-Hey!!!,
I have seen it used where minimum noise, at minimum mass, with minimum mass are all quite important. I have seen standard Si steel fall flat on its face in the same service, so I have some faith that although the numbers are going to show its better side, that it is worth investigating.

With lower loss and comparable saturation flux density to steel leaves what must be higher perm, similar to the Rp, gm and mu of the triode relationship.

Anyway, a 4-mil standard Si steel core is working quite well in my amp now. Small gap is added with some poly film. The gapped inductor is where it's AT, in complete agreement with you folks there.
cheers,
Douglas
Question Authority, disobey it only after understanding it, and when absolutely required...
dave slagle
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Post by dave slagle »

With lower loss and comparable saturation flux density to steel leaves what must be higher perm, similar to the Rp, gm and mu of the triode relationship.
i'm not sure high perm means anything. What i want is linear perm. There are so many contradictions in the logic that make my head spin. Some argue that once you airgap nickel all the high perm goes away hence you are wasting all the good the material offers. With any appreciable gap the final inductance is independant of the core material since air dominates the equasion. By this logic all cores should sound the same unless of course there is more to it than the one-dimentional view that high perm is the only figure of merit.
Anyway, a 4-mil standard Si steel core is working quite well in my amp now.
what grade steel is that? M-2?? I used ot have a chart of grade vs. thickness but lost it in a crash.
Small gap is added with some poly film. The gapped inductor is where it's AT, in complete agreement with you folks there.
any guesses as to why? what is your specific use?

dave
PakProtector
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Post by PakProtector »

Hey-Hey!!!,
This is for a PP grid choke. The 4 mil Si steel is M1 maybe? M4 at 11 mil, M3 at 9 mill and M2 at 7 mil.

On the gap, I suspect that the more constant inductive value presents a more even load. If L isn't varying all over the place, neither is the self resonance point.

I did a bunch of stuff that might look bad to the religious fanatics: SS band clamp to hold the two halves of the core together...:) However this did allow me to adjust the pressure on the spacers quite evenly and I matched the impedance at frequency at a few points with ease.

I am tired of the dope smoking winder who keeps up that rant about gapping stuff like Ni. Even if air dominates the core response for the easy to measure stuff, it is still following the flux in the gap. Since it is involved, why should it not play into the way the device reacts to signal?

Without some more discussion, I don't think my speculation will be of much value.
cheers,
Douglas
Question Authority, disobey it only after understanding it, and when absolutely required...
dave slagle
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Post by dave slagle »

PakProtector wrote:Hey-Hey!!!,
This is for a PP grid choke. The 4 mil Si steel is M1 maybe? M4 at 11 mil, M3 at 9 mill and M2 at 7 mil.
i thought so... I didn't realize you wer using a C-core. I have some .006 nickel stamped lams and couldn't imagine what .004 would be like.
On the gap, I suspect that the more constant inductive value presents a more even load. If L isn't varying all over the place, neither is the self resonance point.
well golly gee.. i never thought of the self resonant point moving around... very interesting.
I did a bunch of stuff that might look bad to the religious fanatics: SS band clamp to hold the two halves of the core together...:)
I do worse than that every day... i routinely tell people that they don't need to clamp things when playing with the gaps since the DC will do a better job than any clamp. When they finalize their gap selection i then have them clamp and report any sonic changes.
However this did allow me to adjust the pressure on the spacers quite evenly and I matched the impedance at frequency at a few points with ease.
do you mean inductance? what frequencies are we talking about?
why should it not play into the way the device reacts to signal?
because you throw all your perm away. maybe we can find a way to recycle it. If we get one of those blue containers and save all the wasted perm and put it on the curb for Wednesday pickup the practice of gapping for linearity will catch on.

dave
PakProtector
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Post by PakProtector »

Hey-Hey!!!,

from Sir Slagle:
do you mean inductance? what frequencies are we talking about?

Well, since I was only measuring voltage across the inductor and a series resistor, I was measuring impedance. I did it at 40, 120 and 360 cps( as nearly as I could measure in 3x increments of frequency ). That some of the impedance might have been due to approach of resonance ( at 1k cps or so ), the L would have been slightly complicated to pull out with the Z=omega-L equation by itself.

I don't care who is doing the gapping of signal inductors. For those who do, they will be better served by the appropriate device. The customers will seek out the good stuff eventually. If their religious doctrine dictates what they build with...how are you going to argue with Faith?
cheers,
Douglas
Question Authority, disobey it only after understanding it, and when absolutely required...
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