e performance from 1-Hz offset to 1,000-Hz offset.
Worryingly, I have started receiving unpleasant personal emails from list
members suggesting that I do not question factual correctness of other's
opinions.
This will explain why I am going off the list for the sake of everyone's good.
Leo Bodnar
> Well part of it comes from designing, testing, and manufacturing a few
> thousand OCXO designs over the years. We likely built 10’s of millions of
> OCXO’s over the time I was doing / managing that.
It might be just my personal opinion but credential swinging is better left out
of technical
cal.
>
> > On Jul 10, 2019, at 3:49 AM, Leo Bodnar wrote:
> > It depends whether OCXO is designed for long term stability and low ageing
> > or low phase noise.
> > Low ageing requires low drive but low phase noise needs as mu
I did, sorry, - it was a finger slip.
Now, what I find kind of funny is that one of the meanings of "monotonous" is
"repetitious or periodic" which is almost exactly the opposite of monotonic.
Leo
> From: "David G. McGaw"
> Leo -
> I do believe you mean non-monotonic, rather than
> From: Bob kb8tq
> Drive power on an OCXO will pretty much always be below a milli-watt. A
> typical design will be in
> the range of 1/10 to 1/100 of that power level.
It depends whether OCXO is designed for long term stability and low ageing or
low phase noise.
Low ageing requires low
It's not very good, it is highly non-linear and even worse - nonmonotonous.
It sometimes produces runt pulse glitches when you roll time backwards.
I have used them in GPS clocks for many years but never enabled them for end
user mode.
It's really a very primitive delay line series and I don't
Bob, what are you calling "time correction"?
You are now quoting F9T which is not the product original statement related to
(F9P.)
If you refer to internal Ublox adjustment of instantaneous timepulse train then
it is performed at navigation rate - up to 20Hz on F9P.
F9P's rate of TP can be set
Correction on all Ublox receivers including F9P is done at navigation rate
which can be set as high as 20Hz.
Leo
> From: Bob kb8tq
> Frequency of any GNSS output on the F9P is limited by the accuracy of the
> time pulse.
> Correction is only done once a second.
In a (almost) ideal coaxial cable (almost) *all* RF electromagnetic field is
inside the cable.
Unlike ladder balanced transmission line where it is everywhere else in the
universe.
Leo
> From: Peter Vince
> sure of the best advice to give him. I'm sure I heard that you should
> never drop the
Hi Dana,
I am just saying that, properly implemented, PLL and FLL are indistinguishable
as long as output signal is concerned while lock is present and that the phase
slew at regaining lock in PLL loop is counterproductive for one but necessary
evil for others. I have a feeling that FLL is
Hi Karl,
I will work on better website description. There are few loops in the device -
GPS reference is PLL and the synthesiser is now FLL (used to be PLL.)
Leo
> Hi, Leo. The web pages for your precision frequency references say they use
> PLL. Is that just for frequency generation, and
I have to draw your attention to practical aspects of why some designs use FLL
rather than PLL.
Consider a GPS locked OCXO outputting GPS synced 10MHz signal.
Properly designed control loop will not produce much (if any) difference when
the reference (GPS signal) is present. In the end,
LeoNTP uses short-circuit tolerant LVCMOS driver with 3.3V level output.
> Does the LeoNTP BNC output come up in the last configured state?
Of course it does.
Leo
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to
Apologies, teletype did not let the picture through
http://www.leobodnar.com/files/2x%20ECOC%203v6.png
> I had half a dozen of 38.88MHz ones for tinkering.
> There is nothing exciting about them apart from a noisy LDO which has peaking
> around 70kHz.
> Spurs are mine.
> Leo
I had half a dozen of 38.88MHz ones for tinkering.
There is nothing exciting about them apart from a noisy LDO which has peaking
around 70kHz.
Spurs are mine.
Leo
On 25 May 2019, at 17:00, Gerhard Hoffmann wrote:
> Has anybody out there more information about this oscillator?
> Its data
> From: Denny Page
> Initially, the units were connected to puck antennas that are literally side
> by side. At approximately 19:15, the units are taken off the puck antennas
> and connected to the single antenna through the splitter.
> I really didn?t expect such a dramatic change.
It does
Assume that the device does not have any reliable long term non-volatile memory
that you can update.
In the absence of any clues your only reliable piece of knowledge is that the
cold start date is somewhere after the date of manufacturing or, most often,
firmware compilation date.
This is the
Based on your requirements I would recommend an orange one.
Leo
> From: Jim Palfreyman
> Hi all,
> I think I'm in the market for a new digital multimeter.
> Could I have some recommendations?
> Jim
___
time-nuts mailing list --
Tobias,
Have you measured resulting phase noise of the finished unit?
Thanks
Leo
> From: Tobias Pluess
> sure, I believe you since my primary requirement was phase noise. This is
> because I'd like to use the OCXO as reference for my spectrum analyzer and
> also for my HP 8663 signal generator
Fluke 96040A disagrees from the back bench.
Leo
> From: Tom Knox
> Much more expensive, but in a class by itself is the Rohde SMA100A option B22.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to
E44xx-AP/DP are a bit rubbish in PN department. I have tested a few units at
1GHz and the results were within 1-2dB from the datasheet, so have a look
there. Don't even bother with -A/D models.
If you are looking for HP 8664A/8644B class performance, have a look at
IFR/Aeroflex/Marconi 2041
Would this work? http://www.wenzel.com/wp-content/parts/501-09371.pdf
I have few of these, they have good enough PN to be used as run-around
reference source for measurements: http://www.ebay.com/itm/16307191
Leo
> From: Jeff Blaine
>
> Wondered if anyone had seen some sort of gadget
Considering that Ublox won't even sell the stock part unless you are willing to
buy 100,000 units I doubt they will listen to anyone representing several dozen
hobbyists. Their biggest argument for having 100k MOQ is "we are afraid that
you will need support."
I would say (without much
Hi Chris,
By query I meant poll settings, sorry.
Your screenshot shows 1MHz configured on TIMEPULSE 2. I don't think it is
going to work.
Standard products used to have 1kHz frequency limit on TIMEPULSE 2. I have not
checked any FTS functionality recently.
The manual (Receiver Description)
to conclude, the quantization noise that we have is very systematic
> in its nature,
> On 1/9/19 10:10 AM, Leo Bodnar wrote:
>> Depends what you call "systematic"...
>
> From: Magnus Danielson
> Leo,
> Now, what I was talking about was frequency/time-in
Depends what you call "systematic"...
I can only speak for Ublox but it is fairly representative of modern (even
though its architecture did not change for almost 10 years) GPS chipsets.
The quantisation runs off internal cheap XO or TCXO that is PLLed to produce
MCU core clock that is then
rom: "Chris Caudle"
> On Wed, January 2, 2019 4:15 am, Leo Bodnar wrote:
>> Here is the phase noise at 10MHz
>> http://www.leobodnar.com/files/mini%20GPS%20clock%20-%20phase%20noise%2010MHz.png
> Does that plot have enough resolution to show any narrow band sp
Here is the phase noise at 10MHz
http://www.leobodnar.com/files/mini%20GPS%20clock%20-%20phase%20noise%2010MHz.png
There will be overall noise increase of about 4dB at 15.6MHz
Leo
On 1 Jan 2019, at 17:00, time-nuts-requ...@lists.febo.com wrote:
> From: Mark Goldberg
> Leo Bodnar's GPSDOs do
Hi,
For those who missed it - IS-GPS-200 has been updated a few months ago.
https://www.gps.gov/technical/icwg/IS-GPS-200J.pdf
Leo Bodnar
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman
29 matches
Mail list logo
