• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

oscillator impeadence

Status
Not open for further replies.

elton

New Member
8) The formular for resonance f = 1/(2pi*sqrt(L*C)) does not tell the specific values of L and C. There are an infinite set of values that give the desired frequency (big L, little C, or big C, little L, etc.) Articles on oscillators sometimes say something like "for 40 meters" use a coil with a certain reactance. Where does one learn to derive the desired reactance value for a particular frequency?
 

john1

Active Member
Hi elton,

At those frequencies thats coils of less than
thirty turns, just fiddle about til it goes right.

Its not infinite in practise, cos there is
capacitance between the turns, so there would be
a maximum resonance frequency to any coil.

There are calculations based on DIA and TURNS
and probably the CORE (SLUG) which will give the
henries. These are usually approximate because
lots of things can influence the result.

Maybe someone could post them, i generally just
guess then fiddle about. If it involves oscillators
and tuning, then my guess is you'll end up fiddling
about to get it right anyway.

Best of luck with it,
John
 
Status
Not open for further replies.

Latest threads

EE World Online Articles

Loading
Top