Difference between revisions of "Frequency Counter"
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* [https://github.com/TheHWcave/PIC-freq.counter-modification/ PIC-freq.counter-modification] | * [https://github.com/TheHWcave/PIC-freq.counter-modification/ PIC-freq.counter-modification] | ||
* [https://owenduffy.net/blog/?p=11386 DL4YHF 50MHz counter on a Chinese TB-244746 PCB] | * [https://owenduffy.net/blog/?p=11386 DL4YHF 50MHz counter on a Chinese TB-244746 PCB] | ||
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== Case == | == Case == | ||
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[[File:FreqCounterLabels.jpg]] | [[File:FreqCounterLabels.jpg]] | ||
| − | == Pre-Amp == | + | == Rework - Add Pre-Amp == |
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| + | * Pre-Amp schematic | ||
| + | * Based on https://www.youtube.com/watch?v=0BxpMm6SLoE | ||
| + | * Uses extra transistor that would have been used by crystal tester oscillator | ||
[[File:FreqCounter_PreAmp_Schematic.PNG]] | [[File:FreqCounter_PreAmp_Schematic.PNG]] | ||
Revision as of 11:57, 3 October 2020
- Original Design
- AliExpress Frequency Counter - Very inexpensive
- PIC-freq.counter-modification
- DL4YHF 50MHz counter on a Chinese TB-244746 PCB
Case
- P-Touch white on black labels
Rework - Add Pre-Amp
- Pre-Amp schematic
- Based on https://www.youtube.com/watch?v=0BxpMm6SLoE
- Uses extra transistor that would have been used by crystal tester oscillator
- When building kit, do not install
- Front side cuts - blue
- Jumpers Red
- Back side cuts
- Details of preamp input pin
- With parts
Testing
- 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
