On 12/05/2012 08:03 AM, Fabio Eboli wrote:
I'm seriously thinking to attempt a gpsdo.
It's mainly to learn something new.
For some reason I collected some Rb oscillators,
and I'd like to have a 10MHz absolute reference,
so I will try to discipline one of the Rb, and
later maybe an OCXO.
The proj
There is a nice XOR mixer in the 9046 PLL chip. Also a dual F/F mixer. Don't
use other versions of the 4046. They have detector dead spots.
You also have the advantage of being able to use them with signals from about
100 mV to 5V.
I haven't used the chip for the purpose mentioned.
Simo
Bob Camp wrote:
> Hi
>
> You might be surprised by the noise floor of an XOR run at 125 KHz. They
> are quite good at that low a frequency.
>
> Bob
An XOR, unlike a mixer, does not have a null when the
phases are in quadrature. This is the fundamental problem
with using it as a phase detector.
R
Hi
Digitizing two signals and winding up 170 db down is maybe a bit more
complicated than just going to quadrature and getting rid of the need to do
so…. at least for a one off application.
Bob
On Dec 5, 2012, at 9:00 PM, Jim Lux wrote:
> On 12/5/12 2:45 PM, Marek Peca wrote:
>>> This last
On 12/5/12 2:45 PM, Marek Peca wrote:
This last idea is interesting... could be simulated by Matlab or similar.
It is known to work in ordinary non-linear transistor-based mixers. It
will produce more messy spectrum than double-balanced mixer, however,
for this purpose and completely within dig
Hi
You might be surprised by the noise floor of an XOR run at 125 KHz. They are
quite good at that low a frequency.
Bob
On Dec 5, 2012, at 8:24 PM, John Miles wrote:
> That would be a good way to do it. I wouldn't use an XOR gate or other
> digital phase detector for this, due to the low s
That would be a good way to do it. I wouldn't use an XOR gate or other
digital phase detector for this, due to the low slew rate among other
things. Instead, you could phase lock two of your sources with a
double-balanced mixer, then run the IF through a lowpass filter and a quiet
opamp or other
You can always use an external mixer / phase detector and the baseband
input of a HP 3048A or FSUP.
Just to name a few:
For low power (+7dBm) you can use a SRA-3 which goes from 25kHz to 200MHz
SRA-3MH +13dBm from 25kHz to 200MHz
SRA-3H +17dBm from 50kHz to 200MHz
For high power signals use a RA
Hi
If you make the leap to - my control processor will be a PC, feature creep is a
bit easier:
1) The "email when in trouble" feature
2) Wireless network interface
3) Ethernet network interface
4) HDMI video for that 1080P status display
5) Full keyboard and mouse for data entry
6) 16 TB raid ar
Over the last two years or so I've put some thought into various home brew
alternatives to purchasing a surplus or new GPSDO. The goal for me would be to
have a reference source that combined the short to medium term stability of one
of my best OCXO's with the long term stability of a GPSDO.
Hans,
would mixing your 125KHz with a 2.5MHz or 5MHz low noise reference to get
it into a range that the analyzer can read work?
You could use a system like the Miles timepod phase noise analyzer, a
mixer, a 5MHz low-noise reference, and a low-pass filter to make use of the
>500KHz lower
Good list Bob,
many people underestimate what it takes to make a working, commercial
GPSDO, especially one that has to perform in volume and beyond a single well
taken care of unit in a Ham shack.
Once you have taken care of items 1) and 2), the real work begins. This is
where our custome
This last idea is interesting... could be simulated by Matlab or similar.
It is known to work in ordinary non-linear transistor-based mixers. It
will produce more messy spectrum than double-balanced mixer, however, for
this purpose and completely within digital domain, it makes absolutely no
This last idea is interesting... could be simulated by Matlab or similar.
On Wed, Dec 5, 2012 at 11:34 PM, Marek Peca wrote:
> running mode and lock the other one to the first one using an XOR gate and
then use the output of the XOR gate as an output signal. However, we are
wondering i
running mode and lock the other one to the first one using an XOR gate
and then use the output of the XOR gate as an output signal. However,
we are wondering if any of you know a better idea. Maybe there is an
off-the-shelf piece
Nearly any idea is better than the XOR gate you proposed. A simp
>> running
>> mode and lock the other one to the first one using an XOR gate and then
>> use
>> the output of the XOR gate as an output signal. However, we are
>> wondering
>> if any of you know a better idea. Maybe there is an off-the-shelf piece
Nearly any idea is better than the XOR gate you p
Hi
The lower limit on the TimePod may not be a hard limit. I believe it's 200
KHz, so maybe double the frequency ...
Bob
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Azelio Boriani
Sent: Wednesday, December 05, 2012 4:57 PM
To: Disc
Yes, I have taken a look and the FSUP is 1MHz min at the signal analyzer.
Timepod? No, 500KHz min... an R&S FAM modulation analyzer?
On Wed, Dec 5, 2012 at 10:48 PM, Bob Camp wrote:
> Hi
>
> A "3048" style measurement with the carrier suppressed by lock should do
> pretty well. If the XOR's are
Hi
A "3048" style measurement with the carrier suppressed by lock should do
pretty well. If the XOR's are out, there are a lot of mixers available that
work at 125 KHz. A simple op-amp buffer and a sound card could do what you
need to do.
Bob
-Original Message-
From: time-nuts-boun...@fe
Hi
The TBolt does a resolution somewhere better than 0.1 ns. It (in some cases)
has been shown to hold better than 1 ns stability. That would be hard to do
with a low resolution timing setup.
Some seem to like 100 seconds as an averaging time, others seem to want
something longer. If you have a
For phase noise the frequency range is 1MHz to 8/26.5/50GHz
The spectrum analyzer works from 20Hz to max.
Adrian
Azelio Boriani schrieb:
Isn't the FSUP a 110K euros equipment 20Hz-50GHz capable? 125KHz shouldn't
be a problem. I had an FSUP for 25 seconds to play with... really
impressive but t
Don't forget that an OCXO needs faster than 10K seconds EFC updates, that's
why you need resolution first.
On Wed, Dec 5, 2012 at 10:24 PM, Volker Esper wrote:
>
> Am 05.12.2012 18:31, schrieb Bob Camp:
>
>> Hi
>>
>> If the intent is to come up with something in the same league as the TBolt
>> t
Isn't the FSUP a 110K euros equipment 20Hz-50GHz capable? 125KHz shouldn't
be a problem. I had an FSUP for 25 seconds to play with... really
impressive but too limited test time to appreciate fully.
On Wed, Dec 5, 2012 at 1:14 PM, Bob Camp wrote:
> Hi
>
> Just about any of the high speed CMOS pa
Am 05.12.2012 18:31, schrieb Bob Camp:
Hi
If the intent is to come up with something in the same league as the TBolt
there are a few other things you will need:
1) Something to compare the two pps signals to within 0.1 ns
Following Ulrich Bangerts suggestions, that a loop time constant s
On 12/05/2012 03:26 PM, Mark Kahrs wrote:
I couldn't resist and did a little reading.
So, the MIT Flea has MOT cells? That would seem to be the deal breaker to
me. The rest is "just plumbing". And smoke and mirrors.
While participating at the NIST T&F seminars, one of the "tours" was in
fa
Do you have a link for the nifty site?
Date: Tue, 04 Dec 2012 19:22:11 -0800
From: Jim Lux
To: time-nuts@febo.com
Subject: Re: [time-nuts] Time security musing - attacking the clock
itself
There's a nifty website out there that shows the
instantaneous and integrated phase differenc
I wonder if two hardware interrupts on the Arduino itself could not be
used for phase locking? There's also an ARM 80 MHz version of the
Arduino package that might be applied, admittedly at higher cost...
Don
Jim Lux
> On 12/5/12 12:06 AM, Bruce Griffiths wrote:
>> Hal Murray wrote:
>>> albertson.
Hi
I was hoping somebody had worked out a way around that.
Bob
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Bruce Griffiths
Sent: Wednesday, December 05, 2012 12:27 PM
To: Discussion of precise time and frequency measurement
Subjec
Hi
If the intent is to come up with something in the same league as the TBolt
there are a few other things you will need:
1) Something to compare the two pps signals to within 0.1 ns.
2) A large amount of code on the control processor (there are a multitude of
special cases ...)
3) A large amount
A low noise sample and hold is still required.
Bruce
Bob Camp wrote:
Hi
Does the synchronous filter on the PWM still have a sample and hold in it, or
has somebody come up with a different approach?
Bob
On Dec 5, 2012, at 3:06 AM, Bruce Griffiths wrote:
Hal Murray wrote:
alber
I couldn't resist and did a little reading.
So, the MIT Flea has MOT cells? That would seem to be the deal breaker to
me. The rest is "just plumbing". And smoke and mirrors.
On Tue, Dec 4, 2012 at 8:23 PM, wrote:
>
>
>
> In a message dated 12/4/2012 6:10:36 P.M. Eastern Standard Time,
> docd
Hi everyone,
As Tom suggested, I redid the test with less than 1 ft. of wire from the
PPS output to the GPIO without any logic gates or line receivers. Same result,
the SKG25A1 was 2 microseconds ahead of the 58534A. Without any other way of
testing, I would probably trust the output of the timing
Hello, I've written few messages on this mailing
list, I'm an absolute beginner on timing science.
I've never introduced myself, so this is a sort
of introduction...
Although this has nothing to do with
arduino, reading the post by Chris Albertson
about an arduino-based GPSDO, I will share
what
On 12/5/12 12:06 AM, Bruce Griffiths wrote:
Hal Murray wrote:
albertson.ch...@gmail.com said:
What is the simplest phase detecter that could work? I think only
that, and
then a duouble oven crystal from eBay, a GPS and and Arduido.
You also need a good D2A to drive the EFC on the osc.
A sy
Hi
Does the synchronous filter on the PWM still have a sample and hold in it, or
has somebody come up with a different approach?
Bob
On Dec 5, 2012, at 3:06 AM, Bruce Griffiths wrote:
> Hal Murray wrote:
>> albertson.ch...@gmail.com said:
>>
>>> What is the simplest phase detecter that co
Hi
I have no problem with restoring gear to it's original state. I mostly was
wondering just how much time the considered "enough" back when the 5365 was
made. There's been a bit of drift in things like that over the years. Sounds
like in this case, not as much as in other areas.
Bob
On Dec 4
Hi
Rather major typo there
Should be - 2 us would NOT come as a big surprise.
Bob
On Dec 4, 2012, at 7:39 PM, Bob Camp wrote:
> Hi
>
> Based on a quick look, the SkyNav does not appear to be a timing specific
> part. A 2 us error in a navigation part would come as a big surprise.
>
> Bob
>
Hi
Just about any of the high speed CMOS parts should work. A 74AC86 is about the
earliest part I would trust. Any of the fast logic families that came after
that should do equally well.
Bob
On Dec 5, 2012, at 7:03 AM, Hans Rosenberg wrote:
> Hello Time-nuts,
>
> I have to do a phase noise
Hello Time-nuts,
I have to do a phase noise measurement and I'm wondering if anyone here has any
ideas on that. We have to measure the phase noise of a 125kHz carrier (5Vp-p
signal level). The measurement system should have a noise floor that is
-164dBc/Hz at a distance of 1kHz to 8kHz away fro
Chris
There is a low cost solution and I have the input circuit perfect for GPS
on a $1 gate array I have boards and am presently using Shera original
version. Would like to buy his version 402NE but have not been able to get a
response from him. Have repeatedly asked for help on this list fo
Hal Murray wrote:
albertson.ch...@gmail.com said:
What is the simplest phase detecter that could work? I think only that, and
then a duouble oven crystal from eBay, a GPS and and Arduido.
You also need a good D2A to drive the EFC on the osc.
A synchronous filter of a suitably l
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