Discussion:
FE-5680A 1 pps photo
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Alberto di Bene
2012-02-02 15:50:46 UTC
Permalink
I managed to take a photo at the scope screen showing the 1 pps pulse
from an old FE-5680A (the one that does not need the 5V and does not
output the oscillator signal - just the 1pps).

Exposure was 30 sec, F9. The signal was barely visible with naked eye,
and some jittering is present. The room of course was in complete
darkness, but the reflex of the stand-by led of another instrument
can be seen...

73 Alberto I2PHD

Loading Image...
John Howell
2012-02-02 16:27:03 UTC
Permalink
........and here's another photo of the pulse from one of the newer breed of FE-5680A that require the 5V.
Taken with a Sony Cybershot H5, 8 sec exposure, 'scope is an elderly Tektronix 2252

Loading Image...

John H.
Post by Alberto di Bene
I managed to take a photo at the scope screen showing the 1 pps pulse
from an old FE-5680A (the one that does not need the 5V and does not
output the oscillator signal - just the 1pps).
Exposure was 30 sec, F9. The signal was barely visible with naked eye,
and some jittering is present. The room of course was in complete
darkness, but the reflex of the stand-by led of another instrument
can be seen...
73 Alberto I2PHD
http://dl.dropbox.com/u/15089947/1pps.gif
David
2012-02-02 16:43:10 UTC
Permalink
Odd. Did Tektronix mark it Fluke PM3082? :)

It is nice to know that the current generation of digital cameras can
be used for this application. It is too bad that the image has so
much noise.
Post by John Howell
........and here's another photo of the pulse from one of the newer breed of FE-5680A that require the 5V.
Taken with a Sony Cybershot H5, 8 sec exposure, 'scope is an elderly Tektronix 2252
http://dl.dropbox.com/u/1690159/1PPS_1%20FE-5680E.jpg
Post by Alberto di Bene
I managed to take a photo at the scope screen showing the 1 pps pulse
from an old FE-5680A (the one that does not need the 5V and does not
output the oscillator signal - just the 1pps).
Exposure was 30 sec, F9. The signal was barely visible with naked eye,
and some jittering is present. The room of course was in complete
darkness, but the reflex of the stand-by led of another instrument
can be seen...
http://dl.dropbox.com/u/15089947/1pps.gif
John Howell
2012-02-02 18:20:03 UTC
Permalink
Not odd but my mistake, I took a picture on both 'scopes and the Fluke gave marginally better results, the text referred to the wrong one. Sorry for the confusion.
Post by David
Odd. Did Tektronix mark it Fluke PM3082? :)
It is nice to know that the current generation of digital cameras can
be used for this application. It is too bad that the image has so
much noise.
Post by John Howell
........and here's another photo of the pulse from one of the newer breed of FE-5680A that require the 5V.
Taken with a Sony Cybershot H5, 8 sec exposure, 'scope is an elderly Tektronix 2252
http://dl.dropbox.com/u/1690159/1PPS_1%20FE-5680E.jpg
Post by Alberto di Bene
I managed to take a photo at the scope screen showing the 1 pps pulse
from an old FE-5680A (the one that does not need the 5V and does not
output the oscillator signal - just the 1pps).
Exposure was 30 sec, F9. The signal was barely visible with naked eye,
and some jittering is present. The room of course was in complete
darkness, but the reflex of the stand-by led of another instrument
can be seen...
http://dl.dropbox.com/u/15089947/1pps.gif
Bob Bownes
2012-02-04 04:52:24 UTC
Permalink
Just for completeness sake, here is a screen capture off of my DSA-602 of
the 1pps. Note that the trace starts 500ns _before_ the 1pps triggers the
capture. Ah the wonders of digital sampling.


Loading Image...

Also as a pdf

http://www.fastbobs.com/pictures/1pps.pdf

Bob
Post by John Howell
Not odd but my mistake, I took a picture on both 'scopes and the Fluke
gave marginally better results, the text referred to the wrong one. Sorry
for the confusion.
Post by David
Odd. Did Tektronix mark it Fluke PM3082? :)
It is nice to know that the current generation of digital cameras can
be used for this application. It is too bad that the image has so
much noise.
Post by John Howell
........and here's another photo of the pulse from one of the newer
breed of FE-5680A that require the 5V.
Post by David
Post by John Howell
Taken with a Sony Cybershot H5, 8 sec exposure, 'scope is an elderly
Tektronix 2252
Post by David
Post by John Howell
http://dl.dropbox.com/u/1690159/1PPS_1%20FE-5680E.jpg
Post by Alberto di Bene
I managed to take a photo at the scope screen showing the 1 pps pulse
from an old FE-5680A (the one that does not need the 5V and does not
output the oscillator signal - just the 1pps).
Exposure was 30 sec, F9. The signal was barely visible with naked eye,
and some jittering is present. The room of course was in complete
darkness, but the reflex of the stand-by led of another instrument
can be seen...
http://dl.dropbox.com/u/15089947/1pps.gif
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Rex
2012-02-04 08:36:13 UTC
Permalink
Good image.

So, if I read that right it is a pulse about 1 uS wide and goes from
base of zero volts to about 5.8 V.

Curious why the high level is over 5 V? Is your 5 V supply to the
Rubidium unit up there?
Post by Bob Bownes
Just for completeness sake, here is a screen capture off of my DSA-602 of
the 1pps. Note that the trace starts 500ns _before_ the 1pps triggers the
capture. Ah the wonders of digital sampling.
http://www.fastbobs.com/pictures/1pps.jpg
Also as a pdf
http://www.fastbobs.com/pictures/1pps.pdf
Bob
David
2012-02-04 08:59:11 UTC
Permalink
The probe compensation could be off.

What type of vertical plug-in was used? The Tektronix 11000 series of
oscilloscopes scare me.
Post by Rex
Good image.
So, if I read that right it is a pulse about 1 uS wide and goes from
base of zero volts to about 5.8 V.
Curious why the high level is over 5 V? Is your 5 V supply to the
Rubidium unit up there?
Post by Bob Bownes
Just for completeness sake, here is a screen capture off of my DSA-602 of
the 1pps. Note that the trace starts 500ns _before_ the 1pps triggers the
capture. Ah the wonders of digital sampling.
http://www.fastbobs.com/pictures/1pps.jpg
Also as a pdf
http://www.fastbobs.com/pictures/1pps.pdf
Bo
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