[time-nuts] 10MHz LTE-Lite
alex at pcscons.com
Thu Nov 20 17:34:34 EST 2014
do you have any information about how that "TimePod 5330A works" any
On 11/20/2014 2:08 PM, S. Jackson via time-nuts wrote:
> Hello Mike,
> attached is a 10MHz DIP-14 TCXO Phase Noise plot from a random LTE-Lite
> I had sent out a 20MHz typical phase noise plot some weeks ago, and
> comparing the two they are almost perfectly 6dB apart as would be expected from
> the 20log(n/m) relationship. There are variations from unit to unit of
> course, but it does not seem like one version of the board or the other has
> advantages in terms of phase noise.
> I had also sent out a superimposed plot of the 20MHz and the divide-by-2
> 10MHz output of the same board at that time, and again the relationship was
> almost perfectly 6dB lower at 10MHz versus 20MHz.
> While phase noise follows theory, it does seem that the DIP14 metal shield
> has a beneficial effect on the ADEV stability though. The plots we are
> getting are pretty darn good, and I want to test more boards before I post any
> ADEV, because its quite a bit better than our specification and I want to
> make sure its real.
> The 10MHz DIP-14 boards do not have an isolating buffer like the 20MHz
> boards do, on these the TCXO drives the output directly, so one must be careful
> to set the equipment to 1M Ohms input impedance or use a buffer
> externally, which is what we did to measure the attached PN plot.
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