Paul,

I updated program SOLNOID2 to 3 because somebody had difficulty with
defining the length of a coil as related to the number of turns when there
are only a very few turns on it. Its a more complicated little problem than
you might think. But the length of a coil, 1, the number of turns, 1, 2, 3
etc., and the winding pitch are all insisted on by the program.

So to clarify the point I rewrote the operating instructions. The program
itself remained unchanged.
---
====================================

You have been led up the garden path by the old wives. The L/C ratio has
very little to do with the Q of a resonant circuit. Q is controlled
independently by the losses in L and C. Since the loss in L predominates Q
= omega*L/R.

The ratio L/C, everything else remaining unchanged, affects only the
parallel impedance of the circuit. A high L/C ratio gives a high parallel
impedance. You get a higher voltage gain in an amplifier with a high L/C
ratio when the load is a parallel tuned circuit.

The parallel impedance is given by L/C/R = Q*Omega*L = Q/Omega/C.

Very often L and C are chosen from what you have in the bottom of the junk
box.
----
Reg, G4FGQ


====================================

"Paul Burridge" wrote in message
...
On Sun, 21 Mar 2004 18:54:19 +0000 (UTC), "Reg Edwards"
wrote:

Paul, in approaching the problem from your viewpoint havn't you set
yourself
the task of winding an inductor to have a particular value of Q ?

If you intend to use a solenoid then Q can be increased only by
increasing
its physical size without changing its proportions too much.

Utimately you will need to know what is the Q of a particular size coil,
number of turns, wire gauge, etc. It will be reduced by its proximity to
other components and circuit board by some indeterminate amount. I think
you should stop and check whether you have room for the coil in the
equipment space available. ;o)

Program SOLNOID2 may be of assistance in this onerous task.

Download in a few seconds from website below and run immediately.

Reg, SOLNOID2 has been withdrawn from your site IIRC. I *had* been
using it to great effect, but you presumably made some improvements,
implemented them, and renamed it SOLNOID3 which is what I now use.
Great program!
I'm still none the wiser as to whether it's better to have big-L ||
small C or vice versa, though. :-/
BTW, Reg - can you write a program to work out how I'm going to afford
my Council Tax this year? Thanks! :-)
--

The BBC: Licensed at public expense to spread lies.