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2484 W Clay St
St Charles, MO 63301
United States

Masterclock Keeps You In Sync

Masterclock engineers and builds precise timing and synchronization systems.

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Masterclock's time synchronization devices do everything from ensuring smooth programming transitions for broadcasting studios to helping astronauts with timely liftoffs. Since 1994, our product portfolio of master clocks, time servers, count controllers, digital displays, analog clocks, and PC cards have been trusted to support mission critical applications. We constantly improve production methods and focus our engineering talents toward custom solutions utilizing cutting-edge technologies.  With practical experience and extensive knowledge of timing technology, Masterclock can develop an appropriate timing system for any application. 

Masterclock is Global

Made in St. Charles, MO USA

2016 Innovators Awards Gold Honoree

Winner of 2016 President's "E" Award

2014 Missouri Exporter Of The Year

Active customers over 100 countries on 6 continents

Open worldwide time & date distribution standards

Sync a variety of systems & provide legally traceable time

Global daylight savings time compliance

Flexible support schedule for overseas customers

Masterclock is Quality

Masterclock synchronization devices are designed and manufactured exclusively in the United States, allowing complete control of manufacturing and design quality.

All Masterclock devices are designed in a robust metal case. A commercial-grade metal housing improves shock and vibration performance while preventing electromagnetic interference. This keeps nearby devices from interfering with clock performance as well preventing the electrical signals within the clock from compromising the performance of other electrical products. 

Masterclock analog clocks only use metal movements. After extensive testing, the life of plastic movements is on average two years, which is unacceptable for a commercial grade product. 

Our digital clocks use Light Emitting Diodes (LED). LEDs offer a life that is hundreds of times greater than LCDs and have larger viewing angles, wider temperature ranges, better shock and vibration performance, improved sunlight readability and do not require back-lighting.

 Commercial-grade components are specified and tested extensively. While more expensive, a product made with commercial-grade parts provides a more reliable product with a longer service life.  Masterclock has committed to this philosophy of quality since 1994.

30-Day Satisfaction Guarantee & 5-Year Limited Warranty

Masterclock offers one of the industry's best warranties.

Under this coverage, Masterclock warrants all electronic hardware products against defects in materials and workmanship for 5 years from the date of sale. Masterclock will also pay for transportation if a product is returned for repairs within the first year. If a customer is dissatisfied for any reason, products may be returned within the first 30 days for a full refund. Click here to learn more.


Precise Timing Library
Masterclock Blog


IEEE1588 PTP Grandmaster Clocks
NTP Servers
Time Code Generators


Digital Clocks
Analog Clocks
Count Controllers

Masterclock, Inc. is a woman-owned small business dedicated to manufacturing precise timing devices that deliver quality and value to our customers. Our products are manufactured exclusively in the USA. We offer a 5-year warranty and free technical support.