Attached is what I'm seeing in terms of adev and mdev on my new FTS
4050.
The performance is worse than I had expected, as compared to the
datasheet.
I'm not 100% confident in my test setup, but I'm not seeing any obvious
outliers in the data.
Test setup is as follows:
Counter: HP 53132A
Hi Chris:
If the source of a pulse is 50 Ohms and it's TTL level at open circuit (
0 to 5 volts) and the load is 50 Ohms, then when you connect a 50 Ohm
load the pulse is 0 to 2.5 volts and so setting the trigger to 2.5 volts
is just on the edge of not working. It's best to put a T connector
Thanks for posting the plot. At first glance it looks
close to OK. Remember what you are plotting is
the RMS sum of stability and noise of three things:
your FTS4050, your Z3801A, and your 53132A.
Each of these three instruments will contribute for
good or for bad at different ranges of tau.
What
Didier Juges wrote:
--- snip ---
The question that comes up is: how do I know my GPSDSO is working and
how do I evaluate its stability?
--- snip ---
Couldn't you plot the EFC value vs time, and check whether it tends
asymptotically towards a (pseudo-)stable value ?
Knowing the Hz/V
Hi Alberto:
I don't think so. The crystal oscillator is aging and so the EFC value
should match the aging in the long run. See that plots at:
http://www.rt66.com/%7Eshera/index_fs.htm
To see of a GPSDO is working compare it's 1 PPS output to the GPS 1 PPS.
Have Fun,
Brooke Clarke
--
I'd also be interested in any anecdotes out there with
regard to this subject. Here's my 2 cents...
Start/Stop -- Either way works and gives the same data.
Both ways make your brain spin when you have to
figure the sign(s) of the phase, frequency, and drift.
DUT -- Note sometimes it's hard to
