[time-nuts] questions about oscilloquartz 10MHz module

[Bob kb8tq]

Hi

Backing off a bit:

The 10811 in your Z3801 has an outer heater to allow it to operate at -40C. The “stock” 10811 will run out of
oven power before it gets that cold. The outer oven does nothing other than allowing operation at very cold
temperatures. It cuts out (or should do so) before the main oven gets to a normal operating temperature. 

In a GPSDO, it is questionable if the tempco of the OCXO matters. While disciplined in a normal lab environment, 
the impact of temperature is easily corrected out by a (SA off) GPS signal.  The time that temperature stability 
*does* matter is in holdover. TimeNuts do not seem to operate their GPSDO’s that way….

==========

The big claim to fame of the 10811 is phase noise. Not so much as specified, but as measured / delivered. It was
the first 10 MHz production part to get well past the -150 dbc / Hz point at a 100 Hz offset. *If* the specs in this sheet:

http://www.sungwhatech.com/product/pdf/aging/8663.pdf <http://www.sungwhatech.com/product/pdf/aging/8663.pdf>

are representative, the 8663’s don’t quite get to that level. The typical spec unit is at 1 to 4 ppb over 0 to 70.  That’s
reasonable performance for a modern single oven. I very much doubt they built a true double oven simply to hit
a single oven spec. 

One easy way to find out: Peel one open, take pictures, and repot back :)

Bob

> On Feb 1, 2020, at 7:50 PM, Jeffrey Pawlan <pawlan at runbox.com> wrote:
> 
> I along with many others have purchased a couple of the OSCILLOQUARTZ 8663-XS 10MHz oscillator.  The ebay ad claims it is double oven but the only datatsheet I could find is for a generic 8663.  Does anyone know the actual definition of the XS version?
> 
> It is unclear whether the ones we are buying are the regular phasenoise or if they are the enhanced noise? Have any  of you run a phase noise test of this model?
> 
> Other than smaller size and 12v operation, is this model as good as the HP10811 double oven in my Z3801?
> 
> 
> 
> 
> 
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