Howdy Charles,
Could you tell us more about the PLL, what sort of phase comparator,
filters and so forth. I'd be keen to duplicate and test your configuration.
Thanks,
david
David wrote:
How do you lock your OCXO to the PRS10?
I just use a 1:1 PLL. Some will argue that phase
Hi
Crystals are susceptible to vibration. That’s pretty well documented. They have
resonances in the mount structure. They have a 2G tip sensitivity.
Audio when it “impacts” an oscillator induces vibration. If your noise source
is a rocket engine, then the vibration is “non trivial”. You do
Back in 1997 when working on a car project I saw several failures of AD595
Thermocouple converter chips due to sound. In all cases the bond wire to pin 8
of the CERDIP package failed, presumably due to resonance (I took the top of
the chips to check) A blob of non acid cure RTV silicone rubber
What about the other side of audio-phoolery: audio FFT? I'm thinking more
along the lines of an ARRL FMT.
From: Tom Van Baak t...@leapsecond.com
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Thursday, March 27, 2014 6:10
Thought I'd give a heads up concerning a nice HP 5065A that I will be
offering for sale in the near future.
It has the Patek Philippe analog clock and is in pretty good condition.
Fully checked out and aligned!
Plot against a Hydrogen Maser looks great and beats the original HP specs
handily.
On 26/03/14 22:42, Tom Van Baak wrote:
Did some home-work on third-degree PLL parameters, so now I know why I
failed, as I never tried to do it right.
One thing that Tom's simulator isn't doing is calculating the parameters
for the PID for you, or backwards what characteristics you will get.
All Rb's have XO's and with the exception of the HP5065C all Rb's influence
long term stability only the only exception is the HP which uses a TC
below 0.1.sec, and as Corbe demonstrated ADEV is controlled below 1 sec. by
the
cell. The same can not be said with other Rb's.
Bert Kehren
Anders:
I am a QEX subscriber and have that issue but I haven't built
the circuit.
The author referenced Brooks Shera as the basis for his work.
He uses a Trimble Resolution T GPS for a PPS reference and an
LPRO-101 Rubidium oscillator for the 10MHz.
His circuit divides the 10MHz output from
Hi Anders,
please contact me offline and I will send you a copy of the QEX article.
Rgds Ernie.
-Original Message-
From: Mike George mgeo...@tuffmail.us
To: time-nuts time-nuts@febo.com
Sent: Fri, Mar 28, 2014 7:43 pm
Subject: Re: [time-nuts] Using GPS to Fine Tune a Rubidium
On Wed, Mar 26, 2014 at 5:51 PM, Henry Hallam he...@pericynthion.org
wrote:
I have a Z3805A and a Beaglebone, and would like to set up an NTP
server for the lab. Any kernel drivers and/or setup hints would be
appreciated :)
I've managed (almost by accident) to run my dev boards and related
I might be in Tokyo in late May (2014) with hopefully a spare day or two.
Are there any geek technology or precise time frequency locations /
activities / events / people I should seek out while I'm there? Are there any
high-precision clock or time-nuts or vintage-electronics collectors in
The QEX unit is a spin off of the Shera, how ever the DAC is only 12 bits
covering the full tuning range of the Rb. Shera does it better with 18 bits
and has additional features. I would not spend the money to get a copy.
Bert Kehren
In a message dated 3/28/2014 2:42:55 P.M. Eastern
I just saw Lars' postings on his design and thought I'd throw mine in since
I've been working on a similar low-end goal but doing it a different way.
Not really an Arduino, either, but it's based on an AVR processor and
should be portable to an Arduino. Right now it's still on a solderless
Fellow time-nuts,
Every now and then, a customer runs into trouble. You end up in these
meetings where vendor and customers discuss troubles. I heard about this
one and invited myself along. Turns out my friends at the customer was
attending. Troubles involved dropouts and blips on a
[Nice description. Thanks.]
wd6...@gmail.com said:
I'm sure the short-term stability isn't as good as a PLL, but averaging the
errors over such a long period does have the advantage of making the
sawtooth error pretty much irrelevant.
You don't believe in hanging bridges?
What do you mean
I'm sorry, I don't recognize the reference to hanging bridges.
I don't consider it a PLL because I have no way to measure phase
differences within a cycle.
I have some serial debugging output to see what the code's doing, but I'll
have to think about how to organize it into graphs that would be
wd6...@gmail.com said:
I'm sorry, I don't recognize the reference to hanging bridges.
I guess it was a good thing I mentioned it. Sometimes I feel like a broken
record. It gets discussed here occasionally. There will be lots of comments
in the archives.
Starter version:
tvb: Motorola
OK, now I understand the reference, but not the significance in this
context. The sawtooth error is below the resolution of the counter here.
It does produce noise on the transition between capture counts that I am
filtering out, but it should average out over the long-term integration
that I'm
Hi
The problem is that it can / might / could / will create a “dc bias” in the
noise. When you filter it, you get a bump rather than zero. If your GPSDO has a
47 ns wide sawtooth, that could be a pretty big bump. There’s no way to know if
the bridge is seconds, minutes, or hours wide. You can
On Fri, Mar 28, 2014 at 5:15 PM, Eric Williams wd6...@gmail.com wrote:
OK, now I understand the reference, but not the significance in this
context. The sawtooth error is below the resolution of the counter here.
I think you are right. It hardly matters for your application. I think
you
Tom,
If you have time - you may visit New Japan Radio:
http://www.njr.com/
3-10, Nihonbashi Yokoyama-cho,Chuo-ku, Tokyo 103-8456, Japan
TEL: + 81-3-5642-8222 / FAX: + 81-3-5642-8220
I believe there are people there that also deal or know those that know
about vintage equipment in the area.
Right, I should be able to get that from the TIM-TP message, but then what
do I do with it? Not sure how I can apply a picosecond correction in this
configuration short of adding a programmable delay line chip that would
cost more than the GPS receiver did.
--
eric
On Fri, Mar 28, 2014 at 6:40
Hi
Since the output of your GPS (short term and long term) is likely much better
than your ability to measure (using your setup), why not just drive the clock
with the GPS? You would use far less power and have far fewer problems.
Bob
On Mar 28, 2014, at 5:55 PM, Eric Williams
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