Does this imply that, for RF, the width of the strap is of minimal
importance, and that a 1/4 inch strap is almost as effective as a 1"
strap? It would certainly be less expensive!
George, W3HBM
On 4/25/2018 3:27 PM, hawley, charles j jr wrote:
I gave the reference. 4th edition of Terman, Electronic and Radio Engineering.
Page 22. The chapter on skin effect. The rf current is pushed to the outside
edge of any conductor because the rf current is distributed in such a way as to
make most of it flow where it is encircled by the smallest number of flux
lines. And that’s the outside edge of any conductor. The rf current in the
center obviously would be encircled the most. Terman gives a very clear
description if you can source his text. He states that it is not the amount of
conductor surface, but rather the way in which the conductor material is
arranged. And I do realize that this is a very misunderstood subject. I’m not
saying that flat ribbon doesn’t have skin effect, but just where the rf flows.
Much of the outside surface in the middle of the ribbon has a high resistance
to rf. So if you are using a ribbon of wire, it would have to be much larger
than a round wire to have any advantage.
I have the Radio Engineers Handbook also and it does not have the same chapter
on skin effect.
Chuck KE9UW
[email protected]
Sent from my iPad
On Apr 25, 2018, at 1:34 PM, Josh <[email protected]> wrote:
You're going to have to explain that to a whole lot of high current flat wound
inductors & transformers.
What are you referencing? The only Terman I have handy is Radio Engineer's
Handbook.
73
Josh W6XU
Sent from my mobile device
On Apr 25, 2018, at 11:17 AM, hawley, charles j jr <[email protected]>
wrote:
RF does not flow on the entire surface of flat copper tape (Electronic and
Radio Engineering by Frederick E. Terman 4th Edition, p 22). The RF current
only flows on the outside edges of the strip, not on the middle outside
surfaces. Think of looking at the end of a longitudinal slice out of a solid
copper rod.
Chuck KE9UW
[email protected]
Sent from my iPad
On Apr 25, 2018, at 12:32 PM, Fred Jensen <[email protected]> wrote:
Sounds like you're following the rules. You might consider flat copper tape
instead of wire for bonding. Lightning is an RF event and currents will be
confined to the outside surfaces of the conductors. Consequently, the surface
area rather than volume of the conductor is what matters most. The conductors
on one of the original transmission lines from Hoover Dam to Los Angeles were
hollow.
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