[time-nuts] Sulzer 2.5 For Sale

Tom Van Baak tvb at LeapSecond.com
Sun Oct 22 18:01:22 EDT 2017

Hi Ruslan,

> this standard appears to be ancient 

Yes. Sulzer oscillators are among of the best quartz frequency standards ever made. Good reading:

"Brief History of the Development of Ultra-precise Oscillators for Ground and Space Applications"

"Design and Performance of Ultraprecise 2.5-mc Quartz Crystal Units. (Warner, A.W.)"


The Sulzer 2.5C and 5B oscillators are highly sought after by time-nuts, given the history, the space-era construction inside, and (if you're lucky, or need a project) the amazing e-13 level of performance out of these standards:


You don't need to read Japanese to appreciate this wonderful set of teardown photos:



----- Original Message ----- 
From: "Ruslan Nabioullin" <rnabioullin at gmail.com>
To: "Discussion of precise time and frequency measurement" <time-nuts at febo.com>
Sent: Sunday, October 22, 2017 12:55 PM
Subject: Re: [time-nuts] Sulzer 2.5 For Sale

That system clearly is a rudimentary (simply based on amplitude)
failover controller---e.g., a shoestring setup could have an EOL
cesium standard (relatively-accurate but -unreliable) that's not on
UPS and a UPS-backed OCXO (like this unit) (relatively-inaccurate but
-reliable) connected to ``REF IN'' and ``STBY IN'', resp.  Honestly
this standard appears to be ancient and the high-level build quality
appears to be questionable.


On Sat, Oct 21, 2017 at 10:05 PM, Richard Mogford <rchrdm at earthlink.net> wrote:
> Hello
> I am selling a Sulzer 2.5 frequency standard.It is rack mounted with a
> separate power supply and no battery.It also has an “Amplitude Fault
> System.”(I have not been able to find out what this does.) There is a PDF
> manual that I will send the buyer with the equipment.  The switch setting #4
> shows zero milliamps.
> I am not an expert in these devices by any means, but have been running the
> Sulzer for several days using John Miles’ excellent TimeLab software.I have
> pasted in below an Allen Deviation plot for three days of data collection.
> I will be selling the Sulzer on auction on eBay starting on Monday, October
> 23.The starting bid will be $200.Shipping may be around $50.
> Please contact me if you have any questions.
> Richard
> rchrdm at earthlink.net

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