LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Old February 26th 07, 01:42 AM posted to
external usenet poster
First recorded activity by RadioBanter: Jun 2006
Posts: 68
Default Formula for Q of resonant circuit?

On 25 Feb 2007 16:40:59 -0500, M J Dowden wrote:
I am trying to find the formula used to calculate the Q of a
parallel R-L-C resonant circuit. There are a number of questions in
the Amateur Extra test pool[1] that ask this and the formula that I
have does not produce the correct answers.
I have been using Q = (2 * Pi * f * L) / R, but the questions in
section E5G of the test pool don't seem to work with that. The
answers that are produced by that formula are among the
"distracters," suggesting that I am making an obvious error that they
expect some people to make.

The formula you used for Q is for a series resonant circuit - call it Qs.
For a parallel resonant circuit, you should calculate Q as Qp = 1/Qs.

That is, at the end of your calculation, hit the "1/x" key on your

(See also

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Paralel resonant circuit tuning range calculator program. Mike Homebrew 0 March 2nd 07 07:33 PM
Formula for Q of resonant circuit? Lloyd General 0 February 26th 07 10:02 AM
Is there affordable software I can use to map out circuit traces for a printed circuit board? Cliff Homebrew 5 July 22nd 05 04:43 AM
Formula 1 Juhasz Peter Karoly Scanner 1 March 14th 05 11:09 PM
Resonant and Non-resonant Radials Reg Edwards Antenna 1 January 8th 05 10:27 PM

All times are GMT +1. The time now is 05:05 PM.

Powered by vBulletin® Copyright ©2000 - 2023, Jelsoft Enterprises Ltd.
Copyright 2004-2023 RadioBanter.
The comments are property of their posters.

About Us

"It's about Radio"


Copyright © 2017