Difference between revisions of "Colpitts Crystal Oscillator"
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== Features == | == Features == | ||
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[[file:CP_Osc_Schematic_Rev2.PNG]]] | [[file:CP_Osc_Schematic_Rev2.PNG]]] | ||
− | == Tested With == | + | === Tested With === |
* 4.433 MHz crystal - worked | * 4.433 MHz crystal - worked | ||
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== Prototype == | == Prototype == | ||
+ | [[file:Colpitts_Osc_P1780-720px.jpg]] | ||
* Cut square PCB material for raised pads | * Cut square PCB material for raised pads | ||
* Build on single sided Copper clad PCB material | * Build on single sided Copper clad PCB material | ||
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=== SMT build - Rev 2 === | === SMT build - Rev 2 === | ||
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+ | [[file:CP-OSC_BNC_Rev2-720px.jpg]] | ||
* 12V power | * 12V power | ||
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[[file:CP_Osc_4p43MHz_4_to_30MHz_SMT_BNC_Rev2_tinySA.PNG]] | [[file:CP_Osc_4p43MHz_4_to_30MHz_SMT_BNC_Rev2_tinySA.PNG]] | ||
− | * SMA | + | * SMA connector |
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+ | [[file:CP-OSC_SMA_Rev2-720px.jpg]] | ||
[[file:CP_Osc_4p43MHz_4_to_30MHz_SMT_SMA_Rev2_tinySA.PNG]] | [[file:CP_Osc_4p43MHz_4_to_30MHz_SMT_SMA_Rev2_tinySA.PNG]] | ||
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<video type="youtube">I4bAfDu6F1k</video> | <video type="youtube">I4bAfDu6F1k</video> | ||
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== Assembly Sheet == | == Assembly Sheet == |
Latest revision as of 00:16, 13 October 2021
Contents
Features
- Colpitts Crystal Oscillator
- Useful for binning crystals for use in building crystal filters
- Hand select close crystal frequency values from a pile of crystals
- Made from junk box parts
- (2) 2N3904 transistors
- Standard value 1/4W resistors
- Design from Experimental Methods in RF Design - Fig 7.69
- Built by others (W2AEW, IMSAIGuy, etc)
- Runs from 4V to >16V
- May run at higher voltages, didn't tempt fate
- 15mA with 4.44 MHz crystal at 12V
- 18 mA at 14V
Schematic
Tested With
- 4.433 MHz crystal - worked
- 16 MHz crystal - worked
- 27 MHz crystal - didn't work
Prototype
- Cut square PCB material for raised pads
- Build on single sided Copper clad PCB material
- Large ground plane
Scope Caps
- UUT = 4.4433 MHz crystal
- 8 Digits Frequency Counter shows 4.432285 MHz
- Rigol DS1054Z - 50 MHz scope (100 MHz mod)
- UltraScope
- Waveform triangular
Prototype
SMT Build
tinySA Measurements of SMT Build
SMT build - Rev 1
- 12V power
- 4.43 MHz crystal
- Measured +8.6 dBm into 50 ohm load
- 40 dBm attenuator to protect tinySA
- 8 Digits Frequency Counter shows 4.432298 MHz
- 4 to 30 MHz scan
- Rich even and odd harmonic content
- -60 dBm down outside of harmonics
- 4 to 100 MHz
- 5V Operation
- +4.3 dBm
SMT build - Rev 2
- 12V power
- 4.43 MHz crystal
- Measured +7.56 dBm into 50 ohm load
- 20 dBm attenuator to protect tinySA
- BNC connector
- SMA connector
W2AEW Video
- Wes Haywood EMiRFD circuit