[time-nuts] 10Mhz Sine from Square Wave Synthesizer

Jerry jsternmd at att.net
Sun May 19 22:05:59 EDT 2013

If you only want a house clock from the Rb osc then why go to all the
trouble?  Just put together a low pass filter to the Rb squre wave and get
rid of the higher harmonics above 10 Mhz ... that should give you a clean
10Mhz wave based on the Rb performance


-----Original Message-----
From: Andy Bardagjy [mailto:andy at bardagjy.com] 
Sent: Sunday, May 19, 2013 19:31
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] 10Mhz Sine from Square Wave Synthesizer

Hi folks, I recently picked up a Symmetricom SA.22c rubidium oscillator.
According to the datasheet, it outputs a square wave with programmable
frequency (well you can pick among some set of frequencies).

I'd like to build up a small circuit locked to the square wave output which
outputs a 10MHz sine wave for use as my "house clock" for my various
instruments (spec an, counter etc). I of course could distribute the square
wave, but am concerned about harmonics, among other things.

The FE-5680A uses a AD9830A DDS to synthesize its output. Is a DDS the right
way to go - in terms of performance, phase noise and so on?

I suppose I could do this with a tank or some other analog circuit, but..

Andy Bardagjy

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