Difference between revisions of "Colpitts Crystal Oscillator"
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* Colpitts Crystal Oscillator | * Colpitts Crystal Oscillator | ||
+ | * Useful for binning crystals | ||
+ | ** Hand select close values from a pile of crystals | ||
+ | ** Useful for [[Crystal Filter Design|design of crystal filters]] | ||
* Made from junkbox parts | * Made from junkbox parts | ||
** (2) 2N3904 transistors | ** (2) 2N3904 transistors | ||
** Standard value 1/4W resistors | ** Standard value 1/4W resistors | ||
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− | |||
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* Design from [https://www.amazon.com/Experimental-Methods-Design-ARRL-Inc/dp/087259923X Experimental Methods in RF Design] | * Design from [https://www.amazon.com/Experimental-Methods-Design-ARRL-Inc/dp/087259923X Experimental Methods in RF Design] | ||
** Built by others (W2AEW, IMSAIGuy, etc) | ** Built by others (W2AEW, IMSAIGuy, etc) |
Revision as of 20:01, 20 August 2021
Features
- Colpitts Crystal Oscillator
- Useful for binning crystals
- Hand select close values from a pile of crystals
- Useful for design of crystal filters
- Made from junkbox parts
- (2) 2N3904 transistors
- Standard value 1/4W resistors
- Design from Experimental Methods in RF Design
- Built by others (W2AEW, IMSAIGuy, etc)
- Runs from <5V to >16V
- May go higher, didn't tempt fate
- 15mA with 4.44 MHz crystal at 12V
Prototype
- Cut square PCB material for raised pads
- Build on single side Copper clad PCB material
- Large ground plane
Prototype Scope Caps
- UUT = 4.4433 MHz crystal
- Rigol DS1054Z - 59 MHz scope (100 MHz mod)
- UltraScope
- 8 Digits Frequency Counter shows 4.432298 MHz
- Waveform triangular
- FFT
- 0-50 MHz
- Shows lots of extra noise
- In plastic box
- Fundamental - zoomed in
- FFT 3rd harmonic
- 3rd harmonic down about 20 dB
W2AEW Video
- Wes Haywood EMIRFD cirvuit