[time-nuts] HP 3586A/B/C entirely referenced to 10MHz: A solution II

[Charles P. Steinmetz]

Perrier wrote:

>Turn the crystals 90 degrees so they are perpendicular to the PC 
>board.  Make a simple TL431 temperature regulated circuit (I found 
>it on the web by a google search) with a bit of copper and 
>insulation.  A small supplemental adjustable tuning capacitor and/or 
>varicap circuit may be needed.  It will probably get one as close as 
>the original programmed mod IMHO.

I very much doubt that the stability of the existing crystals in a 
homemade oven would come within two orders of magnitude of a divider 
referenced to a GPSDO.  Not to mention that for the oven to work 
properly, it would have to hold the crystals significantly above 
ambient temperature, which would presumably be rather far from their 
optimum tempco point.

Best regards,

Charles