Hi,
I'm new and trying to get to grips with things.
If I understand correctly, please forgive if I have it wrong, This
locks a 10MHz signal to a 1Hz (1pps) signal. What makes it lock to 10
000 000Hz instead of 999 999Hz or 10 000 001Hz? Just the hope that the
10MHz is exactly that?
Cheers,
W
On 9/25/15 11:40 AM, Jim Lux wrote:
I ran 5 teensys in parallel, driven from the same Rb source for an hour..
They track reasonably well.
and AVAR from the same run
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There is information on this thread on how you can tap into the unit at various
points to get 20 and 60Mhz. Other owners have used a divider to bring it to the
10Mhz frequency desired. I have one of these units and haven't gone around to
dividing it down. I purchased mine from Ebay and the selle
To further demonstrate the Diode - R- C- approach, here (hopefully) is a
screenshot of the raw DAC output vs time on my Arduino Micro (32u4) based
system. For this test the oscillator is free running with an error of about
1 usec per 460 sec or 2.17x10^-9. The horizontal scale is 125 sec/div (1000
Hi
There is no dump of the firmware. The problem you are most likely
having is not firmware related.
If the VCXO i the unit drifts to far it needs to be re-tuned. Until this is done
the device simply sits in a “search for lock” loop forever and ever.
Simple way to do it:
Monitor the VCXO and b
It would be neat to drive one off a disciplined 16MHz synthesizer and compare.
Bill Dailey
> On Sep 25, 2015, at 1:40 PM, Jim Lux wrote:
>
> I ran 5 teensys in parallel, driven from the same Rb source for an hour..
> They track reasonably well.
> The differences are probably due to where they
Hi Can,
I suppose your circuit will work as you describe, but the diode-R-C network
at the output of the HC4046 followed by an A/D converter works fine if your
application is to lock an oscillator to a reference and you don't care if
there is a constant time (phase) difference between the two when
Hi
Once it’s sync’d with GPS, a normal MCU clock should be able to drive it for a
few days if you had some sort of initial calibration process.
Bob
> On Sep 25, 2015, at 9:15 AM, John Ackermann N8UR wrote:
>
> I may be remembering incorrectly, but I thought that you only need the GPS
> for
This absolutely requires GPS all of the time.
In recalculates the entire 1 minute sentence every minute at 00 in the
first 200ms.
But that was a choice. The actual clock could run till you pull the plug.
I choice the get it done approach.
What is key is an accurate stable 1 PPS.
All of that said i
Hi Hal and list,
On 9/24/2015 2:29 AM, Hal Murray wrote:
It runs all the tests again and didn't find any errors, but it remembers that
it has seen an error sometime recently that hasn't been cleared.
That makes sense - I was able to find a log entry in the diagnostic log
saying "self-test fai
I've recently purchased one of the PPS Only FE Rubidium standards from eBay
and, like many others I suspect, haven't been able to get a stable output
frequency that lasts longer than a few seconds from the module.
It appears that the 10MHz source vanishes after a few seconds but this is
controlled
Bob Benward writes:
>
> Continuing this discussion, I have included a PDF showing the past
30days of
> EFC. Amazingly, the drift has reversed direction! Anyone have any
insights
> into this behavior? Each data point represents 10 seconds.
>
I have found that three things can cause this be
Charles like you I have quite a few gpsdo's that are far superior to wwvb
at least on the east coast in reality. But all of that said I actually used
wwvb more for propagation studies to watch the ionosphere. Its always been
interesting.
Not that any of it matters if all of GPS is gone my real inte
I may be remembering incorrectly, but I thought that you only need the
GPS for initial sync; after that shouldn't the processor be able to
maintain the sequence without new GPS input, so long as the timer clock
doesn't drift too badly? From a known starting point, the modulation
pattern should
Hi
Given the (relative) low precision required of the “dummy” timing data, other
sources than GPS can be used. NTP
level precision may be adequate if you have a good NTP source. Of course if GPS
catastrophes are the concern,
accurate NTP probably isn’t going to be a viable thing.
The more in
Paul wrote:
Here is the detailed document on the wwvb d-psk-r.
Interesting solution, and a good study in
persistence. Congratulations! But I thought the main point of
having a working WWVB receiver was as a backup if GPS fails (or for
use in circumstances where WWVB reception is possible
Hello All,
I got a CD74HC4046 and started to experiment. It seems that this is a newer
version, which has another phase comparator instead of the zener diode.
There has been some changes in the chip basically. PC1out is a xor gate,
and PC3out is an RS flip flop. It will give pulses if one source i
The role of the diode is to break the current path to the cap
when S1 shorts the current to ground when PPS 2 occurs.
With the diode, S1 does not short the cap to ground.
Bill Hawkins
-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Alex
Pummer
Sent: Th
Don't know why I was referenced on this. The simple approach is what I
was trying to improve.
But I was only looking at a way to covert pulse width time to voltage
for further processing.
Perhaps linearity is not required in this application.
It's been my experience that controllers with proportio
On 9/24/15 11:02 AM, Hal Murray wrote:
xne...@luna.dyndns.dk said:
External Oscillator (the system clock clock) , or External Timer clock
(limited to system clock/4)
That sounds like they are running the external signal through a synchronizer
and then doing all the logic on the system clock.
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