Topband: Air Wound Coil

[Richard (Rick) Karlquist]

On 8/30/2018 3:44 PM, Guy Olinger K2AV wrote:

> You can also get the edge-wound (flat) 1/4 inch by 1/16 inch coil that they
> use in the ATR-30 rotary coil tuner. That's a killer piece of copper.
> 

Actually no.  Edge wound is inferior in terms of Q to round wire.
It only makes sense for a rotary coil, where it needs to be edge
wound for mechanical reasons.  On a flat strip, the current
crowds to the two edges for the same reasons that cause skin
effect, thereby wasting most of the copper.  Round wires are
immune from this because they have no edges.

73
Rick N6RK