"jim&julz"
wrote in message
...
Greetings.

I have a pixie 2 xcvr currently set for 80m. I
have been wanting to put it
on the 20m band, so I found that I require a
..551uH.

I assume that this would be a terribly easy coil
to wind, but I've never
wound a coil w/ intention of achieving a
specific inductance. If anyone is
familiar w/ the number of turns/gauge etc... for
a .551uH inductor, I would
really appreciate that info.


Use the following formula:

(N^2)*(R^2)
L(uh) = -----------------
(9*R)+(10*L)

L(uh) - Inductance in microhenries
N - Number of turns
R - Radius of single layer coil in inches
L - Length of single layer coil in inches


If the coil is just for RX then you can get away
with using 22 to 24 gage magnet wire. Be sure to
use a coil form to wind the wire on. Then cover
the coil with coil dope, or other material, to
hold the turns in place. That will keep the coil
inductance stable.

Pick a convenient coil form size and just plug in
some numbers, using a spread sheet, until you find
a set of coil dimentions that you like.


--
Leland C. Scott
KC8LDO

ARRL Member
NCI Member

Charter member of the
Lawrence Technological University
Wireless Society W8LTU