[time-nuts] OFC OCXO

[Bruce Griffiths]

Richard Moore wrote:
> Hi Ernie -- thx for the feedback. I have had all of those effects and  
> more with an HP10811A and an EG&G Cinox version of the 10811A, so I  
> won't be surprised to see such things with this one either. I'm going  
> to try it with Bert Zauhar's FLL controller to see how it runs. You  
> can visit my experience to date at:
>   www.moorepage.net/gps2.html
>
> I'll update the site again after I run the OFC for a while.
>
> Best,
> Dick Moore
>   
Dick

The usual way of reducing charge injection transients from a DVM into
the circuit being measured is to use an RC low pass filter between the
circuit and THE DVM.
Charge injection can be somewhat larger for those autozeroing DVMs that
do not use a precharge amplifier to reduce the effect.
panel mount DVMs do not usually have a precharge amplifier.

With a low pass filter it may be possible to reduce the value of the 50K
isolation resistor that you used.
The value is relatively high because it relies on the DVM and wiring
capacitance as the capacitive part of the RC low pass filter.

Bruce