On Sat, 04 Apr 2009 22:23:03 -0500, Spehro Pefhany
wrote:

On Sat, 04 Apr 2009 19:50:29 -0400, the renowned Joseph Gwinn
wrote:


As for manufacture by a HSM, either approach is practical, but the Wyler
approach is far simpler mechanically. In either case, the electronics
part is dead simple by present-day standards, but was a big deal back in
the 1960s and 1970s.


Joe Gwinn

Have you considered the liquid type? They claim 5 arc second
repeatability.


Best regards,
Spehro Pefhany

They can do that but they're surprisingly pricey.