>Remember, a 90 degree bend in a ground wire is an inductor, and you
>want a low impedance
>path for strike current. I would run that 1.5" strap from each
>tower leg, with an 18" radius bend,
>over the foundation, and out to each ground rod.
Is there a (probably empirically derived) approximation for the inductance of a
bend in a wire. For straight wires, a handy approximation is 1 uH/meter. For
a curve, are we basically talking about using a standard single turn coil
formula, with 1/4 turn?
Some online sites give quick and dirty equations along the lines of L=mu0 * pi
* radius.. in any case, an inductance around 1 uH for 1m circumference (radius
= 1/2pi meters.. call it about 6").
This would imply that the 90 degree bend is around 0.25 uH. At 1 MHz, that's
an impedance of around an ohm or two.
TowerTalk mailing list