Why use tank circuit

Discussion in 'Wireless & RF Design' started by suntop, May 14, 2009.

  1. suntop

    Thread Starter New Member

    Feb 9, 2008
    I have a question, why don't we use XTAL (crystal oscillators) instead of RC tank circuit?
    (lets say I don' wanna tune)
    If a XTAL is used shall we get a stable and better output?
  2. Wendy


    Mar 24, 2008
    Crystals can't be adjusted very much, which is why they are more stable. An LC circuit can be adjusted all over the place, which also has it's uses.

    LC circuits have simplier characteristics than crystals overall.
  3. beenthere

    Retired Moderator

    Apr 20, 2004
    When you place your unrelated question into an existing thread, it can be confusing. We ask that you not hijack threads, but always start a new one.

    This is the original - http://www.allaboutcircuits.com/vol_3/chpt_3/12.html

    How much energy can you pull off a crystal, and how much out of a tank circuit?
  4. KL7AJ

    Senior Member

    Nov 4, 2008
    Tank circuits are used in Class C amplifiers to complete the rest of the R.F. cycle. A Class C tube or transistor may only conduct between 10 or 20% of the R.F. cycle, the tank circuit resonates so you get something resembling a sine wave out of the circuit. Tank circuits are also used for impedance matching in most transmitters, regardless of the class of operation.