As I am typing this I am listening on 2m to one of my "will not tin the
braid first, rather cause TVI" hams complaining about the high SWR on his HF
antenna. Some people just never learn.
::How does not tinning braid cause TVI? Or how does tinning braid prevent
it?
If you have to ask, you will never know. Just don't ask me to de TVI your
station.
::Wouldn't have to...in nearly 40 years of hamming, and currently running
legal limit power 1.8 through 144 MHz, I've never had TVI, ever. Or any
sort of RFI that couldn't be fixed at the receptor (appliance being
interfered with), using ferrites or differential cabling in lieu of
single-ended, or by removing inadvertant ground loops. Not once yet.
::For that matter, I'd love to know how tinning braid really accomplishes
anything, since copper is extremely solderable with very inactive flux, and
solder flows to it like a duck to water without doing anything except
getting it hot enough.
Flux is part of the tinning process. If you don't want to "tin", then you
can't use flux.
::Sure you can. There's flux in the core of the solder and it cleans the
base material as the solder is applied. On a visibly oxidized PCB, you can
watch it happen, no scrubbing required.
::The reason "everybody" (military, industrial, commercial enterprises) went
to "hot solder dipped" component leads back in the late 1970s was because
component manufacturers followed no standards at all, and everybody did
whatever they wished to meet military solderability standards. So, the
standard became "HSD" for a little while. But it is no longer, and now that
there are international RoHS standards requiring the use of only non-lead
solders in most everything beginning next year, this "tinning" is becoming
very controversial at least, and is likely to be obsoleted by environmental
standards very soon. In the interim, few component manufacturers use tinned
leads any more, only because this proved to be a solution to a problem that
didn't really exist. (WB2WIK/6)
This is not the first time I have been called Mr. Nobody. Standards are
wonderful. And what is really neat about them is there are so many. While
at RCA Broadcast I (a field engineer) was asked to commission the first
television camera of a new product line. Engineering assured me it met all
applicable standards, which it did. But it didn't make pictures.
::And the bumblebee can't fly, either. But the RoHS standards are a
reality, and conventional solders will all disappear over the next few
years. We'll still have solder, but they'll be lead-free and wetting
qualities will be different from what we've become accustomed to for the
past hundred years. Should be an "interesting" time....(WB2WIK/6)
de Paul, W8AEF
--
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_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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