(please report dead links)

Sites and specific pages

Watchuseek (WUS), High Accuracy Quartz forum - the internet's only High Accuracy Quartz forum

Methods for timing watches (WUS) - valuable lessons on timing your watches

Approaches to thermocompensation (WUS) - useful definitions, explanations and examples

Omega 4 MHz prototype (WUS) - discussion re. the two known Omega prototypes

Casio 4 MHz watches (WUS) - discussion about this little-known watch

Citizen's HAQ methods (WUS) - a discussion on the HAQ methods that Citizen might (or might not) be using)

Trimming a Twin Quartz (WUS) - a thread describing the trimming of a vintage Seiko Twin Quartz

Caranfil - full of interesting, expert views on HAQ

Doensen - the (practically) definitive book on watches for the HAQ collector

Makszy - a man with an impressive collection and an unbelievable dedication to timing them all

Electric Watches - a site full of, well, electric watches - time reference - time reference

MicroSet - Bryan Mumford's affordable watch timer


Stopwatch timing Excel template - the template I created for timing my watches

Seiko battery list - lists cell types, power consumption and SPY for a long list of Seiko (and related) movements

Seiko vintage quartz movement list - lists Seiko movements by date of first release and gives SPY values

(note: there are some conflicts between the SPY values listed in the Seiko battery list and those listed in the Seiko vintage movement list)

Proceedings of the 34th Annual Symposium on Frequency Control, 1980 - contains a paper submitted by Seiko on 'Twin Mode' quartz - the combining of flexural and torsional modes in one crystal. This approach was used in Seiko's Majesta watch, and also appears to be the approach that Bulova have taken with their Precisionist and Accutron II ranges.

Citizen Basic Technical Manual - describes (in brief detail) how Citizen's quartz watches work