Hi Bob,
You've given me a lot to work with. Perhaps the best answer is to put in a
user parameter for how many seconds between updates to consider a lock
condition. For warmup, I had planned to put in a 5 minute holdover period, but
that could easily be user configurable, as well.
Thanks aga
Hi
A GPSDO is nothing more than a PLL that operates at 1Hz. If you use the same
criteria as they do in some systems, as soon as the OCXO pulse is within 1/8
second (sort of 10%) of the GPS, the PLL is locked / converged / doing it's
thing / functioning as it should. It's a time domain system, s
Hi Bob,
I'm not sure I understand what you mean by "45 degree phase error" in a GPSDO.
This isn't a situation where I'm at the right frequency but at the wrong phase:
at least not by my understanding of phase and frequency. Maybe PLL is even the
wrong term. I dunno, but it feels right for th
Hi
Convergence in a PLL has no absolute definition. In some cases 45 degree phase
error = all is running fine.
I would simply track GPS time vs OCXO time and declare it ok when it's inside
some magic number of nanoseconds.
Bob
On Aug 30, 2013, at 7:08 PM, Bob Stewart wrote:
> I finally (t
I finally (think I) understand enough about my hardware and the data that my
PLL is working! Now for the hard part: When do I decide it's converged? I
believe that the maximum time in seconds till convergence is on the order of:
(OCXO range / DAC range) / (error count * DAC volts per step)
Hi
Indeed, the output can never be better than the input with a DDS, but the
Cy2302 is rated at a 90 to 100 ps jitter level. These days sub 1 ps jitter is a
more reasonable spec for those sort of parts.
A lot depends on how wide a band you want to cover. A VCXO can pull +/- 1000
ppm and still
Hi Bob,
Agreed.
I was looking around for some different ideas on frequency multiplication and
stumbled across these "built in VCO" parts such as the CY2302. My first thought
was that they seem to be targeted to multiplying and synchronizing clocks in
digital systems rather than RF multiplicati
Thomas,
As Bob mentions phase noise and ADEV are not the same thing. We have a very
good PN Wenzel here, and it has horrible ADEV. The BVA has much worse phase
noise but 100x or so better ADEV than the Wenzel at 100s. These are apples and
oranges.
ADEV in the low xE-013 for 1s to 30+s is extre
Hi
A discrete VCXO and PLL chip will always outperform the "buit in VCO" silicon
parts. The CY2302 is quite noisy even by silicon standards. Your doubler /
tripler will give you good close in noise, but poor performance broadband. A
lot depends on what the ultimate use for the DDS output is. Th
Hello,
Today many manufacturers are producing 10 MHz oscillators that offer many
advantages over BVA.
Phase noise of < -116 dBc @ 1 Hz with a -175 dBc noise floor, ageing of 5 x
10E-9 per month and a G sensitivity of 5 x 10E-11 /g in all axis is
available on a new product.
Also the short term
I may be mistaken but I thought the very close in Ultra Low Phase Noise was
what the BVA name was built on, even more then Aging. But with the performance
advances of Wenzel and others over the past few decades it is difficult to
justify the price.
Thomas Knox
Ascent Concepts and Technology
4
Steve,
10E-013 means 1E-012. But the BVAs run in the low xE-013, about 10x better than
that. And they are specifically designed to give great ADEV from at least 1s to
30s and more.
Agreed, its very easy to find fantastic phase noise performance from NEL,
Pascal, Wenzel and others. That (-180dB
Hi
The BVA's were specifically targeted at very good ADEV performance. It's sort
of a left brain / right brain sort of thing. The time people look at ADEV and
"close in" is usually 1 second and sometimes 0.1 second. The frequency people
look at phase noise and "really low" is often 10 Hz, and o
Good day all,
Lately I have been contemplating a variety of methods to take a high stability
10 MHz reference multiply it up to a suitable frequency for use a the reference
clock for a DDS, for example 10 MHz to 80 MHz or 120 MHz (or whatever).
On method is to use simple diode based doublers
Said -
I bet you he meant exactly what you said, just had a mistake in the
representation of the exponent. Hope all is well with you. Was just at GD
all week. Regards - Mike
Mike B. Feher, EOZ Inc.
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960 office
908-902-3831 cell
-Original Message
Hi
Just to be very clear:
a spec guarantee of < 1.0 x 10^-13 at any tau between 1 second and 100 seconds
is a very different thing than "generally below 1.0x10^-12 at 1 second".
That said, not all BVA's meet that spec.
Bob
On Aug 30, 2013, at 11:52 AM, Said Jackson wrote:
> Steve,
>
> 10
This brings to mind the early 60's. You could go to Arrow Electronics
on Long Island. The had trays of a large variety of ceramic switch
wafers, switch bodies, shafts, bolts, nuts etc. You simply selected
what your needed to build you MxNxP rotary switch..
Yearning for the past.
Brian
On
I haven't looked on mine, but can you drill a 1/4 in hole and patch in
little pb switches? or patch in the common small 4-pin pcb switches?
looks ugly, of course, but...
Don
Bob Camp
> Hi
>
> Don't know if the switches are compatible, but the 5334 and 5335 are a
> lot more common than the 5345 and
Hi
Don't know if the switches are compatible, but the 5334 and 5335 are a lot more
common than the 5345 and 5370. For that matter I'd bet there are a bunch of
same era DVM's and such that have switches that might work.
Bob
On Aug 30, 2013, at 2:32 AM, Christopher Brown wrote:
>
> Working on
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