Richard Clark wrote:
On Sun, 02 Dec 2007 22:32:50 GMT, Cecil Moore
wrote:

In what, about 2-4 ns?
No, it increases the VF by roughly 2x in a typical coil.
Why don't you already know that fact?

So, 4-8 nS?

My experience in building coils for base or center loaded verticals was
different. The ratio was close to 1:1 at the base if the replaced
length was not long. The ratio approached 2:1 when the coil was moved
up the vertical, towards the center. It almost did not work if the
coil was moved to the tip of the antenna, or to better say, a coil added
to the tip of the antenna was not an effective way to lower the
resonant frequency.

73, Roger, W7WKB