Improved quality factor for quartz oscillators
Bibliographic record
Abstract
For the past 17 years, Hewlett-Packard's Santa Clara crystal facility has produced only SC-cut, 10 MHz, 3rd overtone quartz crystals for precision oven-controlled crystal oscillators. Test data on crystals and oscillators form a data base of almost 200,000 units. All of the units are essentially identical. The resonator design, holder design, and basic oscillator design have not changed during this period. This permits a direct comparison of many properties of a quartz resonator as a function of time, material, and the manufacturing processes used. We have found that the Allan Deviation at a tau of 2700 seconds is an excellent predictor of future oscillator performance and is useful as a new quality control parameter. This is especially important for oscillators required to have good time-domain stability for sampling times of 2,000 to 5,000 seconds. Of interest to crystal and oscillator manufacturers is that the new quality control parameter shows strong correlation with many factors important to oscillator users. In particular, we see a strong relationship between the Allan deviation with a tau of 45 minutes (2700 seconds) and frequency jumps, short-term time domain stability, and several mechanical processes in resonator fabrication (especially surface finish). The use of this single parameter is a more reliable indication of overall oscillator performance than the combination of factors previously used.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.003 | 0.010 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.002 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.006 | 0.003 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".