As usual I cannot refrain to make my mistake: seconds for minutes... yes,
it is 13 minutes not 13 hours.
On Sun, Dec 2, 2012 at 3:54 AM, Bob Camp wrote:
> Hi
>
>
> On Dec 1, 2012, at 8:13 PM, saidj...@aol.com wrote:
>
> > Hi Magnus,
> >
> > yup, at the levels we are interested in, a prefix or tw
Hi
On Dec 1, 2012, at 8:13 PM, saidj...@aol.com wrote:
> Hi Magnus,
>
> yup, at the levels we are interested in, a prefix or two sometimes doesn't
> make any real difference :)
>
> Most of the time typical GPSDO's won't ever drift out of a say +/-100ns
> window. If they do, then the antenn
Azelio,
On 12/01/2012 11:08 PM, Magnus Danielson wrote:
Azelio,
On 12/01/2012 03:17 PM, Azelio Boriani wrote:
Recently
(April 2012), our national broadcaster (RAI TV) research lab (RAI
CRIT) has
published an article in his technical magazine (Elettronica e
Telecomunicazioni http://www.crit.rai
Hi Said,
On 12/01/2012 06:28 PM, Said Jackson wrote:
Hello Azelio,
We added a user adjustable jam-sync threshold some time ago for European
DVB-T applications for that reason. The customer can now decide the phase
window in which the frequency is drifted slowly without a phase jump.
Interesti
Azelio,
On 12/01/2012 03:17 PM, Azelio Boriani wrote:
Here in Europe the use of GPSDOs has dramatically increased with the
transition to the digital TV broadcasting. The single frequency network
(SFN) mode of transmission requires the presence of a time and frequency
reference. The ETSI has a Te
On 12/01/2012 03:10 AM, Hal Murray wrote:
Does anybody know what happens in a TBolt or Z3801? (or any other boxes?)
Suppose your system goes into holdover for long enough to be interesting.
Suppose for discussion that the clock drifts so that the PPS if off by a
mircosecond.
I can see two wa
Hi
One Hz at a GHz is a one ppb. One ppb is one ns / sec. UHF TV is close enough
to 1 GHz to simply call it 1 GHz.
1 us is 1,000 ns, so a 1 ppb offset will zero out the error in 1,000 seconds.
That's roughly 20 minutes.
All this from Bob, who just did the ms / us typo less than a day ago.
Bo
Hi Hal,
We selected 10 steps upon customer request. The counter resolution is 16.667ns
on the FF-IIA boards, so we end up pretty close to UTC.
"Slowly" is determined by the PLL parameter serv:phaseco. By default we add
very little frequency error, so drifting say 100ns can take a couple of hour
Hello Azelio,
We added a user adjustable jam-sync threshold some time ago for European DVB-T
applications for that reason. The customer can now decide the phase window in
which the frequency is drifted slowly without a phase jump.
But I think your math may be off, with default settings we typic
Here in Europe the use of GPSDOs has dramatically increased with the
transition to the digital TV broadcasting. The single frequency network
(SFN) mode of transmission requires the presence of a time and frequency
reference. The ETSI has a Technical Report (TR101-190) where the maximum
time and fre
Hal wrote:
I can see two ways to recover. One is to jump the 10 MHz clock by 10 cycles.
The other is to adjust the frequency so that the PPS slews back to on-time.
The first approach gives you a second with the wrong number of cycles. The
second approach has your clock frequency off for a whi
saidj...@aol.com said:
> New JLT GPSDOs step back in 10 Steps over 10 seconds if more than 250ns off,
> then adjust the last ns slowly.
Thanks/interesting.
How/why did you pick 10?
> If within 250ns, they just slowly slew back.
How fast is "slowly"?
--
These are my opinions. I hate spam.
Hi
Typo…
Sorry
Bob
On Nov 30, 2012, at 9:49 PM, Bob Camp wrote:
> Hi
>
> A few more possibilities:
>
> 1) Slip the clock by one cycle per second rather than 10 at once.
> 2) Take the pps off of a 100 MHz source sync'd to the 10 MHz and slip by less
> than 100 ns per step
> 3) Take the pps
Hi
A few more possibilities:
1) Slip the clock by one cycle per second rather than 10 at once.
2) Take the pps off of a 100 MHz source sync'd to the 10 MHz and slip by less
than 100 ns per step
3) Take the pps off of a DDS and fine tune the slip however slowly you might
wish.
In practice, the
Hal,
New JLT GPSDOs step back in 10 Steps over 10 seconds if more than 250ns off,
then adjust the last ns slowly.
If within 250ns, they just slowly slew back.
Bye,
Said
Sent From iPhone
On Nov 30, 2012, at 18:10, Hal Murray wrote:
>
> Does anybody know what happens in a TBolt or Z3801? (o
Does anybody know what happens in a TBolt or Z3801? (or any other boxes?)
Suppose your system goes into holdover for long enough to be interesting.
Suppose for discussion that the clock drifts so that the PPS if off by a
mircosecond.
I can see two ways to recover. One is to jump the 10 MHz
16 matches
Mail list logo
