Frequency Counter

Discussion in 'The Projects Forum' started by powzoom, Jan 30, 2009.

  1. powzoom

    Thread Starter Active Member

    Jan 18, 2009
    I would like to design a frequency counter for my radio experiments. Up to a 100MHz or so should be fine with 1% error. I'd rather it be simple to build and understand than incredibly accurate.

    I don't really know how to go about designing one. I don't own a pic programmer so I'd like to avoid buying one. Does anyone have a block diagram or an explanation on how they work? I've seen schematics online but they're just that, schematics, with no explanation of how its working. I'd eventually like to be able to understand and design one myself.
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    Very briefly, the input is shaped and applied to a string of counters. A time base very accurately controls the counting period, so the number of counts can be related to the input signal frequency.

    If you can post up a specific schematic, we can be more specific about how it works.
  3. studiot

    AAC Fanatic!

    Nov 9, 2007
    The frequency readouts on most radio equipment do not directly measure the radio frequency.

    Within the radio circuitry the signal is converted perhaps several times between the wanted signal and the carrier radio wave.

    It is much cheaper and easier indicate the radio frequency by using the fixed relationship to one of these intermediate frequencies and measuring that.

    This approach may be a good starting point.