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Now on point:
(1) Is it a simple case to you that I simply misunderstood, confused and misstated DR Bews comments on RFI and dialetrics, but that his position overall is indeed valid ?
Dr Bews published comments and his credentials and industry on-going audio experience as a designer and builder of high-end audio LFD electronics certainly appear persuasive and credible to me and likely to many more of us laymen and non-engineers.
please list all of
- your personal academic and professional qualifications,
- your system gear that is the lab test source of your opinions genesis,
- your personal audio industry verifiable experience, and
- your overall published or acknowledged professional track record
to support your stated position and opinions. It is a matter of credibility assessment now to assess this equally and fully and thus properly.
His comments as reported here are incorrect or misleading. To whit: Simply putting dielectric like PVC, etc, around/between cable wires doesn't 'shield' them from RF. I can't tell if he is being misquoted at some stage or has misworded trying to over-simplify, or if this is for some other reason. I can only comment on what we've been presented with.
However One of the key points made already is that this isn't a matter of who has a PhD, Scout Badge, etc. Its a matter of the basic physics. Best to focus on what is said, not who says it.
If it helps you, though I can give some of my background.
Yes, I have a Piled higher and Deeper which I got in 1981
During my working life I worked for some years as an audio designer for the old 'Armstrong' company, and have continued to take an interest in the topic. I've also worked as a Lecturer - eventually as a 'Reader' - for decades at Uni and during that time supervised over a dozen research students to their PhDs, and taught heaven knows how many undergrads. I also wrote some books on instrumentation (undergrad honours level) and aspects of RF (research level). Plus articles for New Scientist, Nature, Focus, etc. Not confined to audio mags. I'm also an IEEE, AES, and IoP member still.
FWIW I 'won' two UK Prizes from the NPL for measurement systems I devised to make RF measurements to let them improve the *definitions* of the relevant standards. Had a long relationship working for them, along with my old research group.
However none of that changes the basic fact that you can look in the physics textbooks and see that EM radiation and fields will generally pass though dielectrics. You can also measure this if you like. Or simply note that capacitors generally have a dielectric inside them and pass AC. Indeed if you live in a home made of bricks (dielectric) with glass (dielectric) windows, you can probably note that your portable transistor radio may work without you needing to open a window.
So you can cheerfully disregard all the above personal history beyond noting it represents the sort of working background that prompted my comments on this matter. Nowdays, I'm just a retired old fart who writes a bit about audio because I find it interesting. I try to clarify technical issues in case it helps people to make their *own* judgements.
FWIW Curiously here, If anything, having a *bad* dielectic would be preferred if you want it to reduce RFI. Because lousy dielectrics like poor PVC tend to have a higher 'loss factor' (loss tangent is the term engineers may recognise here) than good quality HDPE or PTFE. But this isn't likely to be make much difference at the kind of RF frequencies that will affect most audio kit or propagate along mains wires.
I should also perhaps add that one of the measurement areas I got involved with with NPL many years ago was measuring the properties of dielectrics like PTFE, etc, from near dc up into the mid infra-red. This was of interest as my old group uses PTFE and HDPE for *lenses*. Glass is, of course, also a dielectric. But in the far infra red these polymers have lower loss.