Difference between revisions of "Frequency Counter"
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== Rework - Add Pre-Amp == | == Rework - Add Pre-Amp == | ||
| − | * Based on | + | * Based on |
| + | |||
| + | <video type="youtube">0BxpMm6SLoE</video> | ||
| + | |||
| + | * Uses extra transistor that would have been used by crystal tester oscillator | ||
* Pre-Amp schematic | * Pre-Amp schematic | ||
| − | |||
[[File:FreqCounter_PreAmp_Schematic.PNG]] | [[File:FreqCounter_PreAmp_Schematic.PNG]] | ||
Revision as of 12:03, 3 October 2020
Features
- 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
- Inexpensive plastic case
- BNC connector
- 5.1mm Chassis mount power connector
- 7-9V in
Rework - Add Pre-Amp
- Based on
- Uses extra transistor that would have been used by crystal tester oscillator
- Pre-Amp schematic
- 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
