[Amps] resonance

[Jim Forsyth]

Well it seems to me that the subject of resonance is about the fact that an 
oscillation applied to a resonant system produces the greatest effect in 
that system at a particular frequency. That frequency is of interest because 
it has uses in the real world. In our case it allows us to select out a 
desired radio signal from a spectrum of unwanted signals. It is therefore 
useful to be able to calculate that frequency from the values of the system 
components.

In a parallel tuned circuit containing resistance the frequency at which Xc 
= Xl is not, in general, the frequency at which the greatest signal 
magnification occurs so it is not useful as a definition. It can be used as 
an approximation in cases where the resistance is low enough to be ignored.

Jim, AF6O


----- Original Message ----- 
From: "Bill Turner" <dezrat at copper.net>
To: <amps at contesting.com>
Sent: Monday, June 05, 2006 9:23 AM
Subject: Re: [Amps] resonance


> That depends on how one defines "resonance". As I understand it,
> there are two possible definitions for a parallel tuned circuit:
>
> 1. When Xl = Xc
> -or-
> 2. When the impedance is maximum.
>
> If there is significant resistance in the circuit, the two
> definitions will occur at slightly different frequencies. The greater
> the resistance, the greater the difference.
>
> I remember reading this years ago. Correct?
>
> 73, Bill W6WRT