Also in London, and not to be missed, is James Nye’s Clockworks Museum http://theclockworks.org/museum of precision astronomical regulators and electro-mechanical clocks, including working examples of each of the successive generations of top-accuracy pendulum clocks (Riefler, Shortt-Syncronome, Fedchenko).

Hi Tom

I just wanted to tell you that I got a GPSDO and successfully calibrated the 2.5 MHz Sulzer with it.

I was able to put both waveforms on my oscilloscope and adjust the Sulzer so that they aligned, just as you advised.

Richard