Tuggle Tuner Calculator

This calculator estimates the tuning response across the range of a dual-ganged variable capacitor. Please see the associated wiki entry, Tuggle Antenna Tuner, for more information.

• The default antenna values are for the standard dummy AM receiving antenna.
• Values displayed are rounded to the nearest whole number.
• Frequency 0 is the tuned frequency.
• The maximum Q is the theoretical unloaded Q assuming no losses other than antenna/ground resistance, and the bandwidth shown is based on this.
• You may bookmark or link directly to this result.
• A SPICE deck with these values is available for simulation.
• You may also download Open Document and Excel 97/2000 spreadsheets with the default values.

Some Samples

• 365/365 with spreading capacitor.
• 500/520 with spreading capacitor.
• 160/160 Hi-Q.

References

Mike Tuggle (re)popularized the use of a dual-gang capacitor in the arrangement shown for crystal radio receivers. Though it is usually used as an antenna tuner in a double-tuned set, variations of this circuit can make a fine single-tuned radio.

• Analysis of the Tuggle Front End, Parts One, Two, and Three, by Ramon Vargas Patron.

 \|/                                   Ltnk             
  |                                 +--UUUU--+--------->
  |                                 |      ..|.......   
  |         Lant        Lload       |     /  |     /    
  +---VVV---UUUU---||---UUUU---||---+---||---+---||---+ 
      Rant         Cant        Cload|  /Ctnk |  /Cgnd | 
                                    |        |        | 
                                    +---||---+---||---+ 
                                        Ctnkp    Cgndp| 
                                                      | 
                                                     ---
                                                      - 

©2008 David E. Wagner II.