[time-nuts] Warning: HP oscillators on eBay from todoelmondo(Ray Mahoney)

Richard (Rick) Karlquist (N6RK) richard at karlquist.com
Mon May 9 13:18:33 EDT 2005

, but it looks like a list of 
> numbers folllows this, and not the letter A I'm converned this is 
> perhaps a special, at an odd freqency, and not the standard 10MHz 
> 10811A. Is there any where it actually says 10811A on the 
> package? Can you give me a price to ship to the UK. Address would 

All 10811's of any flavor have 10 MHz outputs.  (Except an extremely
small number of prototypes at 10.23 MHz for a GPS initiative that 
were never released AFAIK).  If you know anything about making
an SC cut crystal of the quality of the 10811, you would know
that changing the frequency requires a huge R&D investment, way
beyond what any special could justify.

There are basically only three models of 10811 made:

1)  With PC edge connector
2)  With coax connectors
3)  Special for the 5071A with extended tuning range,
which is unlikely to show up for sale.

All 10811-6XXXX are simply selections of one of the above.
After a lot of time has gone by, these selections are, for the
most part, irrelevant.   

"Model 10811A" is a nomenclature used in cases where an 
oscillator was sold directly to the end user as a component.
HP was briefly in the merchant oscillator business.  The 
vast majority of 10811's were for internal use.  They all
have 10811-6XXXX numbers.  Many of the 10811-6XXXX numbers
are selected to meet tighter specs than the 10811A spec.
There is nothing superior about an oscillator labeled "10811A".
BTW, it was superceded years ago by the 10811D/E, in terms of
model numbers.

Rick Karlquist
R&D Engineer at HP Santa Clara Division 1979-1998

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