He's back.
>The fact stainless is "magnetic" or not isn't important at radio
>frequencies. Eddy currents and skin effect keep the magnetic properties out
>of the picture.
>
>If you add a solid steel slug core in a coil it reduces inductance, unless
>the core is powdered into such small particles eddy currents are not an
>issue.
>
>The only effect of steel or iron is it behaves as a slightly more resistive
>conductor than some other conductors.
"Slightly more"? Compared to Cu-Zn / brass alloys, Fe-Cr-Ni-Si ...
/stainless steel alloys have 20 - 40 times as much DC resistance per
cubic cm.
>
>Loss is proportional to current density, and current density is so low in a
>typical HF amplifier or tuner enclosure you will NEVER be able to notice the
>difference in loss between using steel or copper.
>
>The exception is cavity type systems at very high frequencies, where
>standing waves concentrate current in small physical areas. In that case,
>current density can be high enough to add loss.
>
>The same goes for bolting connections. Unless a small area has concentrated
>current (either through induction or conduction), there is no effect. By not
>running the current through the bolts or screws, and by using the steel
>hardware to only mechanically clamp things together, there is no ill effect.
Good point
>Once again, magnetic or non-magnetic doesn't matter except as it slightly
>reduces skin depth.
>
>73, Tom W8JI
- R. L. Measures, a.k.a. Rich..., 805.386.3734, AG6K,
www.vcnet.com/measures.
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