>
> Another fundamental problem is that the excellent engineering books on
> ferrites published between the 50s and 70s are essentially lost -- long
> out of print and hard to find even in the best engineering libraries.
> Some of what I've learned and published was well known in the 50s, but
> it died with the retirement of that generation of engineers. FWIW -- I
> heard NOTHING in my EE courses (finished in 1964) about ferrites, even
> though I took as much communications stuff as I could.
I dont know where the National engineers got their start with ferrite
suppression but the basics were around since the 30's and refined during
WW2. They were using beads on leads by the early 60's on SS designs.
I believe I still have a thick Arnold engineering manual and designers
sample kit that was being thrown away at the time of one of their
auctions....or maybe it was the final IRS one in 92. There may be other
period references in the boxes I havent looked at in ages.
In the 80's Ferroxcube and Siemens were into the act and some of that stuff
Ive seen here not too long ago.
Dont know if I mentioned it earlier or if its still valid but TDK had quite
a ferrite line then also. I bought a lot of large and small beads directly
thru a friend in Japan in the 85-95 time frame. Even with shipping, prices
were lower than buying similar volumes thru Fair-Rite
Carl
KM1H
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UR RST IS ... ... ..9 QSB QSB - hw? BK
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