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VK2ZRG > TECH 28.08.08 16:23l 24 Lines 1157 Bytes #999 (0) @ WW
BID : 1604_VK2WI
Read: GUEST
Subj: Skindeep info text
Path: IZ3LSV<IK2XDE<DB0RES<WA7V<VK7AX<VK2TGB<VK2IO<VK2WI
Sent: 080827/2332Z @:VK2WI.#SYD.NSW.AUS.OC #:1604 [Sydney] $:1604_VK2WI
From: VK2ZRG@VK2WI.#SYD.NSW.AUS.OC
To : TECH@WW
VK2ZRG/TPK 1.83d Msg #:2588 Date:27-08-08 Time:11:46Z
SKINDEEP.EXE is a programme that calculates skin depth in 14 different metals.
It also calculates the AC and DC resistance of a round wire. There are three
7+ files of 5.25 kb. It's a DOS programme that will run in windoze up to, and
including xp but, as far as I know, not vista.
Some handbooks have a formula for calculating a so called "Cutoff Frequency"
for a wire whereby, above this frequecy, skin effect must be considered. This
could be misconstrued to mean that you should use thinner wires at higher
frequencies. Such is not the case; thick wires have lower AC resistance and
lower reactance.
The programme also calculates the inductance of a straight round wire. The
inductance formula may be giving a value which is too high. Recent work on a
coil programme, that uses an accurate coil inductance formula, shows the
curious result that a straight wire has LESS inductance if it's wound into
a coil, at least for inductances <1 microhenry or so. (I know that the coil
formula gives the correct inductance.)
73's de VK2ZRG @ VK2WI
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