Seiko Grand Quartz
cal. 9943
Factory Spec. 10 SPY
Thermocompensated: Dual Oscillator (32 kHz + unknown)
User Adjustable: Yes
The frequency of the auxiliary oscillator is not known for sure, but based on a comparison of power requirements between the various Twin Quartz watches in my collection, I believe it is reasonable to assume that the frequency is 40 kHz.
UPDATE - I have sold this watch.
Some details for this watch may be missing as it was subjected to comprehensive testing.
| Parent Company | Seiko Holdings Corporation |
| Brand | Seiko |
| Model Series | Twin Quartz |
| Model Name | Grand Quartz |
| Model Number | unknown |
| Case Number | 8020 |
| Serial Number | 8D0455 |
| Approx. Date of Manufacture | December 1978 |
| Calibre (mvt maker) | 9943 |
| Calibre (brand) | 9943 |
| Factory SPY | 10 |
| TC Appproach | Count adjustment & twin quatz |
| Frequency (XO 1) | 32 kHz |
| Frequency (XO 2) | unknown (40 kHz, assumed) |
| Rate Adjustment | User |
| Major Inhibition Period | unknown |
| Minor Inhibition Period | unknown |
| Power | Disposable cell |
| Cell Number | SR927SW |
| Case Back | Cell hatch |
| Water Resistance | unknown |
| Features | 3-hand, no numeral dial |
| Day, date (not perpetual) | |
| Timing Results | Basic data & Further details |
| Images | Photos - Large File Sizes! |