[time-nuts] Hp10811 parts ref

[Club-Internet Clemgill]

Charles, 
Thank you for this very useful information ! 
My plan is to « clone » as close as possible the initial 10811 design, as it is well proven. 
Except changing the crystal and possibly use modern components if they bring any improvement, and adapting the « mass » to the crystal format and manufacturing it through 3D printing. 
Did anybody tried something similar ? 
Best, 
Gilles. 



> Le 11 sept. 2019 à 22:05, Charles Steinmetz <csteinmetz at yandex.com> a écrit :
> 
> Didier wrote:
> 
>> The LM208 is a single op-amp with low offset (<3mV) and low bias current.
> 
> Even 3mV offset is verging on horrible for a "precision" opamp these days -- it's hard to find any respectable opamp that doesn't do lots better.
> 
> The secret sauce of the LMx08 series is the super-beta input pair, which matches FET opamps for input current but also holds that low (room-temp) input current over the full temperature range (the input current of FET opamps generally rises by at least 10x to more than 1000x at warmer to hot temperatures).
> 
> There is no need for extraordinary measures -- there are a number of more modern opamps specifically designed to upgrade LMx08 sockets.  The OP77 is one:
> 
> <http://pdf.datasheetcatalog.com/datasheet/analogdevices/206654345OP77_c.pdf>
> 
> The LT1012 and OP97 are two more.  I've used both extensively, and finally settled on the OP97 for this sort of application:
> 
> <http://pdf.datasheetcatalog.com/datasheet/analogdevices/140679914OP97_d.pdf>
> 
> Best regards,
> 
> Charles
> 
> 
> 
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