On 7/12/2012 5:48 PM, ZR wrote:
> Considering the YCCC's long time reputation for top level engineering
> ability plus the others mentioned such as K3LR Id consider that article a
> must read.
The 2006 W1HIS piece gets many things very right but some things very
wrong. Tom has noted some things that are wrong. Another is that Chuck
didn't understand the chokes he was recommending and trying to measure,
and he didn't know how to accurately measure them. He also didn't know
about the relatively new #31 material. He wasn't alone in any of that.
I got good measurements by measuring the chokes as the series element of
a voltage divider. Some guys working with the German VNWA have
implemented this in the software that supports it. Some guys working
with the N2PK VNA read the Agilient work on the IV method, and developed
a test fixture to implement it. All three of these methods can get good
data.
I had been working on ferrite research for three years by the time I saw
Chuck's peice, and I corresponded with him about it. One MAJOR point he
got right is the importance of killing RX noise by killing common mode
current on the feedline, and it was one I hadn't thought of. I haven't
seen anything that Chuck published after this (six years ago), but I
consider my work much more advanced than his.
Some top level engineering does, in fact, occur outside New England.
Like in Georgia, and on the west coast. :)
73, Jim K9YC
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UR RST IS ... ... ..9 QSB QSB - hw? BK
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