The Ashtech Z-12T GPS timing receiver requires a stable 20 MHz frequency reference. My lab has only a 5 MHz H-maser reference and a 5 or 10 MHz Cesium reference so the goal is to generate a 20 MHz reference while best preserving the quality of the signal. The following is what I found out about frequency doublers and quadruplers. If you have comments or questions please let me know.
| Generator | 1 second stability | 10 000 s stability |
| 10515A | ||
| 3325B | 6e-13 | 1e-14 |
| FS040 | 1e-13 | 6e-16 |
Photo
| HP 10515A passive (diode bridge) frequency doubler |
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Waveform
Performance
Measured performance
| 3325B -- 5 MHz in vs. 20 MHz out |
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Photo
| Spectral Dynamics FS040-5 active frequency quadrupler |
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Measured performance
| FS040 -- 5 MHz in vs. 20 MHz out |
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These measurements were made with a TSC 5110A time interval analyzer and an Oscilloquartz BVA quartz oscillator reference. The noise floor of the J1 vs. J2 output of the BVA and the noise floor of the channel A vs. channel B input of the 5110A is assumed to be better than the doubler/quadrupler being tested. Here is an actual measurement:
| Noise test of OSA 8607 (output J1, J2) and TSC 5110A (channel A, B) |
| A pair of TSC 5110A Time Interval Analyzers |
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| The OSA 8607 (inside a stainless steel thermal wine bottle holder) |
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In trade for the gum my assistant for this experiment was Nick(8):
/tvb