[time-nuts] Distribution amplifier (again!) - now mostly ok but has gain peaking

Charles Steinmetz csteinmetz at yandex.com
Sun Jan 29 22:31:08 EST 2017

Ruslan wrote:

> Have you looked at the design of the HP/Agilent/Keysight E1750A (sine
> timebase of various standard frequencies)...?

According to the specifications on the 5087A/E1750A/E1752A spec sheet, 
the 1750A is no better WRT phase noise than the 5087A, and the 5087A is 
distinctly ... mediocre ... in that regard (not helped at all by having 
an AGC loop).  Phase noise was obviously not HP's first design priority.

Since the OP is seeking better PN performance than his first design, 
which already has 10dB less PN than the 5087A, studying these HP 
distribution amp circuits will probably not be very instructive.

That said, if you have service manuals for the 1750A or 1752A, I'm sure 
many owners would be grateful if you post them -- they seem to be hard 
to find.  Didier's site is one good place:


Best regards,


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