Hi Tom,
I am just curious... What did you mean if the GPS was warmed up? Do you
mean the Jupiter GPS unit its self to be warmed up? (if so, what does
the Jupiter unit have to do with the oscillator stability, besides
providing that 10KHz signal?)
Great info, thanks.
Do you have any
For sale
lot of 4 OCXO
2x Oscilloquartz 8676-AT 5 MHz 12V. (Used)
2x Isotemp OCXO91-30 5 MHz (brand new)
for 50.00 Euro + shipping rate
extimated shipping cost for europe 45 Euro, Italy 14 Euro.
If interested email me directly to: tim...@timeok.it
Luciano P. S. Paramithiotti
IZ5JHJ
Hi Brad,
I've had no problems so far. I bought a couple on a free postage deal (took
about a month). Both worked fine, and just in process of building them into
a case.
Communications with the guy in China were first class. You also need to
realise, that you are getting one hell of a deal with
Hello,
As it has been discussed in the past days, the architecture of the newer
FE-5680A that has been recently purchased by a lot of us does not led to
a trimming resolution through the serial port of 1.7854e-7Hz, but rather
leds to think that the trimming resolution is in fact 6.80789e-6Hz
Wow, good work, a very fine reverse engineering attempt.
On Sun, Jan 29, 2012 at 12:45 PM, Javier Herrero jherr...@hvsistemas.eswrote:
Hello,
As it has been discussed in the past days, the architecture of the newer
FE-5680A that has been recently purchased by a lot of us does not led to a
Hi Javier,
On 01/29/2012 12:45 PM, Javier Herrero wrote:
Hello,
As it has been discussed in the past days, the architecture of the newer
FE-5680A that has been recently purchased by a lot of us does not led to
a trimming resolution through the serial port of 1.7854e-7Hz, but rather
leds to
El 29/01/2012 13:57, Magnus Danielson escribió:
Hi Javier,
On 01/29/2012 12:45 PM, Javier Herrero wrote:
Hello,
As it has been discussed in the past days, the architecture of the newer
FE-5680A that has been recently purchased by a lot of us does not led to
a trimming resolution through the
Hi
Very interesting.
It sounds like dithering would be needed to get down to parts in 10^-14. If we
do that from an external device (PC / PIC / FPGA / whatever) it would be useful
to know the delay between the serial command and the DDS update. The more
variable the delay, the less accurate
Hi
That is indeed an odd update rate. The short term stability of the FE-5680 is
in the parts in 10^-13 range once you get past 100 seconds. I would think
updates of a DDS lsb or more would mess up the stability.
Of course if it is temperature correction, it may still be in the noise.
Bob
On 01/29/2012 02:45 PM, Bob Camp wrote:
Hi
Very interesting.
It sounds like dithering would be needed to get down to parts in 10^-14. If we
do that from an external device (PC / PIC / FPGA / whatever) it would be useful
to know the delay between the serial command and the DDS update. The
Hi
Yes, I think the dither would just be a minor routine running on what ever you
use to discipline the rubidium. Other than a disciplined environment I don't
see a lot of need for sub 7x10^-13 steps.
Bob
On Jan 29, 2012, at 9:12 AM, Magnus Danielson mag...@rubidium.dyndns.org
wrote:
On
Hi
If you lock up a simple VCXO with a basic PLL, your 10 GHz LO will flop around
a couple hundred hertz on a second to second basis. To get good performance
off of GPS you need long averaging times. Your oscillator needs to be pretty
stable without the GPS. That is where some sort of TCXO or
El 29/01/2012 14:45, Bob Camp escribió:
Hi
Very interesting.
It sounds like dithering would be needed to get down to parts in 10^-14. If we
do that from an external device (PC / PIC / FPGA / whatever) it would be useful
to know the delay between the serial command and the DDS update. The
At 05:45 AM 1/29/2012, Javier Herrero wrote:
For example, the following data has been gathered:
Serial offset 00 00 00 00
DDS A word: 44 02 62 F6 = 1141007094 = 5 313 228.32219 Hz
DDS B word: 43 FD CC 8E = 1140706446 = 5 311 828.32085 Hz
Can you do a test at +/- fullscale offset as well?
I'm now gathering the unit self-updating of DDS data, that will take
somewhat long... so I will try later or tomorrow. Since we have seen
that the DDS values are reported back in a response to a command, it is
easy to do without the need to have anything hooked to the SPI bus :)
Regards,
I wonder if anyone in the group might have any technical info on a
Leitch CSD-510 clock system driver I believe it was made for the
broadcast ind. I have tried web searches but only find sellers of the unit.
Don
wa9ylp
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Hi
If you try to do full scale, check the range of your VCXO first. The digital
test is much easier if you already know where your VCXO stops tuning.
Bob
On Jan 29, 2012, at 1:45 PM, Javier Herrero jherr...@hvsistemas.es wrote:
I'm now gathering the unit self-updating of DDS data, that
Hi
A roughly 30 second update rate makes a lot of sense. That would keep the
update steps buried in the short term stability noise.
Good news on the serial update timing and it's stability. Sounds like you could
do several updates a second. That's plenty fast enough.
Bob
On Jan 29, 2012,
Whilst downloading some information from Trimble's support pages today I
discovered, only two years late:-), that in January 2010 Trimble released
firmware upgrades for the Acutime Gold, Mini-T, Resolution T, Thunderbolt E,
and no doubt other GPS units too.
Trimble states in each case.
Speculation... just for fun.
Seeing Javier's great recent work on the 5680 DDS operation has me thinking
more about two of the mystery commands. If the unit is applying a periodic
correction to the DDS frequency beyond what the user requests via RS-232
commands, as a function of (for
Hi
Unlike a GPSDO, a rubidium does not have a reference to construct a table
against. If they are doing temperature correction, it would run on a factory
loaded table.
Bob
On Jan 29, 2012, at 5:35 PM, John Beale be...@bealecorner.com wrote:
Speculation... just for fun.
Seeing Javier's
On Sat, Jan 28, 2012 at 10:50 PM, Ray Xu rayxu...@gmail.com wrote:
Also, what is the advantage of using a OCXO instead of a VCXO in terms of
short-term accuracy? If the PLL time constant is only a few seconds, then
a crystal shouldn't deviate in frequency by too much within a few seconds,
In a message dated 29/01/2012 21:54:02 GMT Standard Time, gandal...@aol.com
writes:
No firmware update seems to be available for the original Thunderbolt,
nor
for other earlier units, which probably isn't too surprising but I don't
recall anyway ever noticing periodic dropouts of this
I seem to recall seeing this (or perhaps for the 'non-II' units) in the past
but can't seem to find it.
Can anyone point me to the pin outs and interconnects for these units?
Thanks in advance.
Joe
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On Sun, Jan 29, 2012 at 10:19 AM, Javier Herrero jherr...@hvsistemas.es wrote:
El 29/01/2012 14:45, Bob Camp escribió:
My next intention is to replace the OCXO in one of my Thunderbolts with a Rb
and use a small microcontroller to get the voltage correction from the
Thunderbolt through the
Hi Chris
Thanks for your helpful input.
What do you mean by average? Do you mean that the GPS and PLL must be
kept on for 20 minutes to hours, or did you mean that the PLL loop filter
must have a time constant of 20 minutes to several hours? To me, the
latter seems really unpractical for
Hi Erno
Thanks for your suggestion; while it is convenient to have everything
already planned out, I'm inclined on DIY'ing as much as I can :-)
Ray Xu
On Sun, Jan 29, 2012 at 1:01 AM, Erno Peres erniepe...@aol.com wrote:
Hi Ray,
please find on this link the info what you are looking for.
Don't confuse the PLL loop time constant with the time constant of
the analog or digital filter.
They are not the same.
Bruce
Ray Xu wrote:
Hi Chris
Thanks for your helpful input.
What do you mean by average? Do you mean that the GPS and PLL must be
kept on for 20 minutes to hours, or did
Hello Nuts,
I've been trying to get the analog EFC to work on the FE-5650A (a very
close cousin of the FE-5680A). On these oscillators it is normally on
pin-8 of the DB-9 (Option 12 and 30). As one of the serial lines is on
this pin, I traced the jumper that is placed for the EFC option(s).
What do you mean by average? Do you mean that the GPS and PLL must be
kept on for 20 minutes to hours, or did you mean that the PLL loop filter
must have a time constant of 20 minutes to several hours?
You have to compare the characteristics of the oscillator with the
characteristics of
The sawtooth error in the PPS output and how they were able to correct
it externally was interesting. I have seen that kind of problem
before in DDS and other applications.
I wonder what other GPS receivers provide either PPS outputs without
sawtooth noise or a correction message.
On Sun, 29
Hi Skip:
I just got the Lucent OMR module with a FE-5650A.
Do you know if there's hook-up info for the OMR?
http://www.prc68.com/I/FEIFS.shtml#FE5650A
Have Fun,
Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/Brooke4Congress.html
Skip Withrow wrote:
Hello Nuts,
I've
Hello,
Also I expect that the range would be somewhat limited by the unit
software, since the control word is 32-bit, same as the DDS program word
with, and I don't think that the little thing would enable to program
the DDS from zero to 32-bit. In any case, my idea was first to only
monitor
El 30/01/2012 03:19, Chris Albertson escribió:
On Sun, Jan 29, 2012 at 10:19 AM, Javier Herrerojherr...@hvsistemas.es wrote:
El 29/01/2012 14:45, Bob Camp escribió:
My next intention is to replace the OCXO in one of my Thunderbolts with a Rb
and use a small microcontroller to get the
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