This is fun. Some homework, I don't have access but I think this will shed some light... Phys. Rev. 105, 896 (1957): Thermal Fluctuations in Conductors
Care to elaborate on that?
What do you mean by "bundle winding"? Are you using that term to mean the same as random winding or scramble winding?
High frequency resonance is the result of leakage inductance and winding capacitance. Layer winding keeps winding capacitances very low.
Here's a CineMag CMLI-15/15B which is a layer wound transformer. No resonance problems there.
An externally hosted image should be here but it was not working when we last tested it.
se
How does it do that? By making the windings more inefficient and increasing the winding resistance?
se
resonance "Q" measurements can be very sensitive, but it helps to have a model to put those sensitive measurement numerical results into
for MC step up I think we're talking about ~10 Ohm source Z from the cart, and pretty much 1st order pre-emphasized signal from the disc
within the xfmr bandwidth you need the source impedance of these noise mechanisms to calculate their significance when paralleled with the cart R
the step up ratio shouldn't be too large, giving poor bandwidth, large leakage, which could "decouple" the source Z image at the secondary from the noise "at resonance" beyond the xfmr bandwidth
if it is then you have the bigger issue of not enough bandwidth for audio
I also really doubt any xfmr lamination "eddy current loss noise" will be increasing faster than the RIAA pre emphasized signal with increasing frequency
for MC step up I think we're talking about ~10 Ohm source Z from the cart, and pretty much 1st order pre-emphasized signal from the disc
within the xfmr bandwidth you need the source impedance of these noise mechanisms to calculate their significance when paralleled with the cart R
the step up ratio shouldn't be too large, giving poor bandwidth, large leakage, which could "decouple" the source Z image at the secondary from the noise "at resonance" beyond the xfmr bandwidth
if it is then you have the bigger issue of not enough bandwidth for audio
I also really doubt any xfmr lamination "eddy current loss noise" will be increasing faster than the RIAA pre emphasized signal with increasing frequency
As far as core losses are concerned: Quote without comment.
"Then if an eddy-current loss of 6dB is acceptable at 16kc/s (Hz) the lamination thickness must not exceed 6 mils, and for the same loss at 600Kc/s it must not be more than 1 mil." p.50 'A Survey of Factors Limiting the Performance of Magnetic Recording Systems'
JAES, Jan. 1957 E. D. Daniel et al. Most authors were with the BBC. Daniel was with National Bureau of Standards, Wash. D.C.
Hopefully you will get a copy and believe what they say. Equations are provided, on a previous page.
"Then if an eddy-current loss of 6dB is acceptable at 16kc/s (Hz) the lamination thickness must not exceed 6 mils, and for the same loss at 600Kc/s it must not be more than 1 mil." p.50 'A Survey of Factors Limiting the Performance of Magnetic Recording Systems'
JAES, Jan. 1957 E. D. Daniel et al. Most authors were with the BBC. Daniel was with National Bureau of Standards, Wash. D.C.
Hopefully you will get a copy and believe what they say. Equations are provided, on a previous page.
Cine-Mag will take my design, out of spec. Eddy current losses. Want to find out?
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Hopefully you'll start providing some information that's relevant to audio transformers instead of tape heads.
se
You don't even know what your "spec" is.
I mean, how can you even know what your spec is if you've never quantified it in the first place?
se
Ah, ok.
Anyone using it in audio transformers? It doesn't look to be a very efficient winding.
And in any case, transformers without any resonance problems can be had without it.
se
No, everyone, I have not yet found any audio transformer info of any significant sophistication, except for Sowter and his 4 mil lams.
Yeah, has been used in custom mic and line transformers.....dead flat out to well past 20k.
Eric.
Eric.
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