Difference between revisions of "Frequency Counter"

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Line 23: Line 23:
 
* 5.1mm Chassis mount power connector
 
* 5.1mm Chassis mount power connector
 
** 7-9V in
 
** 7-9V in
 +
* Right angle header pins pointing to inside of card
 
* 4-40 x 3/16” Machine Screws
 
* 4-40 x 3/16” Machine Screws
 
* 4-40 Standoffs
 
* 4-40 Standoffs

Revision as of 13:53, 3 October 2020

FreqXounter-Kit-Assembled-02.PNG

Features

Case

  • P-Touch white on black labels

FreqCounterLabels.jpg

Rework - Add Pre-Amp

  • Re-uses extra HF transistor that would have been used by crystal tester oscillator
  • AC coupled input
  • Based on

Pre-Amp schematic

FreqCounter PreAmp Schematic.PNG

When building kit, do not install

FreqCounter DoNotInstallParts.PNG

Cuts/Jumpers

  • Four cuts
    • Blue = 1 front side cut
    • Green = 3 back side cuts
  • Jumpers Red

FreqCounter Rework PCB Front.PNG

  • Green = Back side cuts

FreqCounter Rework PCB Back.png

  • Short etch on one cut

FreqCounter Rework-Cuts-Back.PNG

  • Details of preamp input pin

FreqCounter Rework-06.PNG

  • With parts

FreqCounter Rework-07.PNG

Testing

FreqCounter InCase.jpg

  • 4.9152 MHz crystal
  • Scope frequency counter shows 4.19520 MHz
  • Freq Counter displays 4.9747 MHz
  • Difference = 500 Hz or 0.1% accuracy
  • Can only adjust the variable capacitor in narrow range

Reviews / Builds