[time-nuts] Common-View GPS Network

[Magnus Danielson]

Tom,

On 04/17/2013 07:21 AM, Tom Van Baak wrote:
>> Tom, you scare me some times, this is one of them... or the time actually.
>
> Magnus,
>
> I remember why I didn't measure the M12 oscillators directly -- it's a real challenge to get at the signal on the back side of the PCB and to measure it without loading the crystal. It's not like just connecting a wire to a 50R Timepod input. Here are photos of the oscillator on three different versions of the M12 board:
>
>      http://leapsecond.com/pages/m12/m12-osc.htm
>
> Perhaps with some 'scope tracing you can find a buffered clock output on one of the ASIC pins. That way the same probing technique could be used on all 3 boards.

OK, now you start to make sense ;-)

Only #2 should be a challenge, as #1 and #3 has buffered output. Still, 
you want some buffering. A suitable CMOS gate should pull it off. 
Otherwise a FET-probe to a PSU and then into the TimePod should do the 
trick.

Cheers,
Magnus