Using GPSDO 10 Mhz as REF signal, I was able to calibrate OCXO. And
now its potentiometer position was nether at its both extremes. The
reading on 5386a (using 10 sec gate) fluctuate from 9.3M to
10.7M. Again, may be I need to wait much longer when OCXO
will be stable.
So,
The problem with using a 1 Hz reference when looking at a nominal 10 MHz
signal is that you will get a stable scope display with no drift when the
input is *any* integer number of cycles/sec. So 10,000,000 Hz will give a
stable display, but so will 9,999,999 Hz and 10,000,001 Hz. Unless you
know
Hi
OCXO’s come in many different “flavors”. Some older units with rack mount
designs may take 1 day simply to warm up. Older AT based units might take 10
minutes simply to stop pulling maximum power.
Stopping the maximum power pull does *not* indicate they are done drifting. Wit
an AT drift
The problem with using a 1 Hz reference when looking at a nominal 10 MHz
signal is that you will get a stable scope display with no drift when the
input is *any* integer number of cycles/sec. So 10,000,000 Hz will give a
stable display, but so will 9,999,999 Hz and 10,000,001 Hz. Unless you
Dave,
The trick is to closely synchronize your 1PPS generator, whether you use the
1970's method of a string of seven '7490 decade divider chips (common reset) or
a 1900's method of a sync'able MCU divider such as a picDIV
(http://www.leapsecond.com/pic/picdiv.htm).
It's so simple it's
Yeah, I considered saying that. But if you don't have a TI counter, you
need some way of resetting the divide-by-1e7 chain so the two 1 Hz pulses
are close enough in time that you can see them on the scope at some
reasonably fast sweep rate. Yes, you can used delayed sweep, but how
stable is the
Hi
You would need to add another power supply into the 5386 case and rig it to
always be on. You would also need to fit the MV89 in there. The
MV-89 pulls about 5X more power than the OCXO HP used in similar counters. It’s
also roughly 5X the volume.
The simple / cheap / high reliability /
I tried to use 1PPS as Ext. trigger for the oscilloscope. I was able to
stabilize signal movement. Then I tried to calibrate OCXO. However its
appeared out of range (I reach end of potentiometer limit but counter
still shows that OCXO is out of 10Mhz). Which kind of suspicious.
Then I decide
Hi:
I also have a HP5386, it has very limited inside space, I think the MV89 is
too big to it, even MV89 is small size in familiar OCXO, so if I need mor
accurate, I used a extend GPSDO for its 10M stand.
Hui Zhang BA6IT
Sent from my Moto X
已通过我的 Moto X 发送
2015年4月25日 上午11:46于 d0ct0r
Hello,
The input: HP 5386A which I would like to calibrate, Well warmed Tremble
Thunderbolt (1PPS only), 10 Mhz Datum OCXO (unknown accuracy), Rigol
1101E Oscilloscope.
The goal is to calibrate counter to read the Datum OCXO.
===
Reading the manual for 5386A,
Why not use a T connector to patch the 10 MHz to two places at once?
Bob
On Friday, April 24, 2015 5:06 PM, d0ct0r t...@patoka.org wrote:
Hello,
The input: HP 5386A which I would like to calibrate, Well warmed Tremble
Thunderbolt (1PPS only), 10 Mhz Datum OCXO (unknown
Currently, 10 Mhz output connected to Linear LTC6957-3 to feed DDS and
MCU for another purpose. Of course I am able to reconfigure (physically
disconnect) it. But I am just curious if its an option to use only 1PPS
for calibration.
Regards,
V.P.
On , Bob Albert wrote:
Why not use a T
Following my request, I am curious about modding of HP 5386A. My unit
has TCXO. Is it possible to replace that existed TCXO by third part OCXO
? Like Morion MV89A, for example ?
--
WBW,
V.P.
___
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To
Just feed the PPS into the scope trigger on step 2.
The low repetition rate on the PPS would make this difficult on an
analog scope; on a digital scope it is easy. You can use any
sub-harmonic that is less than or equal the counter reference frequency
(10 MHz).
Brent
On 4/24/2015 3:45 PM,
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