In the device manager, choose View: Show hidden devices. The grayed
out devices have once been, but are no longer, connected to your
machine. Remove the ones that you no longer care about. You can also
remap the comport-numbers in the properties of the serial port devices,
use the button
On the topic of minimum hardware to use a TBolt,
I am interested in observing clock pendulums.
WWV is a long way from Australia and only available with good
propagation.
A GPS receiver will give accurate seconds signals, even if there is
some jitter,
however it is not easy to identify which
The GPS may drop out, so a disciplined oscillator is in order, but
how can you get the GPS signals parsed to identify say minute markers
without running a computer?
There are lots of 8 bit micros that are smart enough to parse the stuff from
a TBolt and wiggle a few pins. You have to be
The unit powers up about +200 Hz above 10 MHz (mine is modified to no
longer put out 15 MHz). After 30 minutes it has dropped slowly to +150
Hz. It briefly shows an online indication then. But a few minutes
later that goes off and the fault light comes on. The frequency drops
as low as +129
My pendulum produces pulses at a rate of one per second.
That signal clocks a latch that samples the less significant bits of
my reference oscillator (100kHz or 1MHz)
in a counter.
The latched values drive a 12 bit D-A converter (a R - 2R chain).
So I have a phase signal updated every second,
Hal,
My LPRO is 4 or 5 milli Hz high. I can't see any changes
with temperature and my setup swings through 15 F p-p
during most days.
The TC of a LPRO is in the order of -7E-13 / Deg C or even less. That is
why you see no changes: They are there but a bit beyond most measurement
Hi Richard --
At the moment we're not taking orders as the demand has outstripped the
supply. If -- and there's not much likelihood of this -- we end up
having any available, we will first notify those who've already tried to
order but were put on hold, and if any are left after that, there will
Yeah, you really do need a display... this is the 21st century... monkeys
got better things to do than count blinkenlights (or read a message scrolling
across a six character LCD).
You need a processor of some sort to decode the TSIP messages. It actually
takes a significant amount of
Hi Neville,
As a thought, you might want to look at a Basic Stamp from Parallax.
These are PIC chips (at least they used to be) coupled with an EEPROM
and are programmed in BASIC. Here's a site for some additional data -
http://www.parallax.com/Default.aspx?tabid=295
Regards,
Bruce Raymond
Yeah, you really do need a display... this is the 21st century...
monkeys got better things to do than count blinkenlights (or read a
message scrolling across a six character LCD).
A simple blinking LED is handy to alert you that there is a problem.
I was probably assuming that you
Sorry, I don't like to contradict,
but I have different experiences made concerning
some statements:
On Sun, 6 Jul 2008 20:48:27 +, Mark Sims wrote:
The Thunderbolt default config is to not save the survey position. Unless you
use some software to save the position, every time you power
As I reported already, Thunderbold seem to restart perfectly alone
once set properly, until I get a problem I have no real control
over it, no information about, and for portable use I need always a
PC.
I think portable is quite different from stationary.
If you move it, you have to
Greetings, all,
I am in need of the following Opt PCB's for the HP 5087A:
Qty. 3 5087-60011 (5 MHz to 10 MHz Doubler)
Qty. 115087-60012 (10 MHz Amplfiers)
Any spares out there?
Please pass the word.
TNX
Doc
NE8S
___
time-nuts mailing list --
On Mon, 07 Jul 2008 12:21:29 -0700, Hal Murray wrote:
As I reported already, Thunderbold seem to restart perfectly alone
once set properly, until I get a problem I have no real control
over it, no information about, and for portable use I need always a
PC.
I think portable is quite
My pendulum produces pulses at a rate of one per second. That signal
clocks a latch that samples the less significant bits of my
reference oscillator (100kHz or 1MHz) in a counter.
...
but what I would really like is a clock showing UTS in a form that
can be compared to a clock.
That
As I said:
The Thunderbolt default config is to not save the survey position. Unless you
use some software to save the position...
The reason your Thunderbolt does no self surveying at power-on is exactly
becuase you DID use some software to save the position!The TAPR units were
shipped
On Mon, 2008-07-07 at 21:14 +, Mark Sims wrote:
BTW, on 30 July 2017 your Thunderbolt turns into a pumpkin... its
interpretation of the GPS week number fails and it may or may not keep
working. At a bare minimum, the time and date will be wrong (see
ThunderBoltBook2003.pdf page
If you look at what a Thunderbolt was originally designed for (a fixed cell
site TF reference), then you are right, they are designed to be powered up
and left to sort themselves out - self survey, and then provide TF outputs
when everything has stabilised.
Rob K
-Original Message-
From:
[EMAIL PROTECTED] said:
I've created a ntpd refclock driver for the Fury GPS receiver. The
refclock is based on the NMEA driver.
Neat/thanks.
There is currently a major reluctance to add new drivers to the main ntpd
source pool.
I think we should add this logic to the hpgps driver.
The
Maybe just build it into the generic parse refclock? I just needed
to get it up and running and a standalone driver was the path of least
resistance.
The neat thing about the gpgga string is that it happens every second and
doesn't
rely on ntpd to send a command for it. It gives you a nice
The manual doesn't give much direction on tweaking the disciplining parameters.
Also, not having anything better to compare results to, I'm pretty
handicapped. Has anybody done any tweaking and perhaps can offer any
suggestions?
Over the weekend I was able to get a GPS antenna on the roof
NE8S [EMAIL PROTECTED] wrote:
I am in need of the following Opt PCB's for the HP 5087A:
...
Qty. 115087-60012 (10 MHz Amplfiers)
Good luck. I like to a have some more of these as well.
I have considered doing a run of 60012 boards. This would be
straightforward except for one thing: I
Tom Clifton wrote:
The manual doesn't give much direction on tweaking the disciplining
parameters. Also, not having anything better to compare results to, I'm
pretty handicapped. Has anybody done any tweaking and perhaps can offer any
suggestions?
Over the weekend I was able to get a
There is nothing special about the 5087A's amplifier cards. The 5087A
design is not especially quiet; in fact, it will degrade the broadband floor
of a Thunderbolt by a good 7 or 8 dB from what I have seen.
I'd say grab some PCB prototyping stock and a Dremel tool, and surf through
Bruce's notes
The Thunderbolt attempts to align the specified PPS and OSC edges with the GPS
satellite time signal. The PPB parameter is its estimate of the error of the
oscillator edge from where it needs to be. They specify it in mysterious
parts-per-billion, but never really say billions of what.
Did your zero key stick ??
If I counted all them zeros correctly I get 1 part in 10e24 ???
Man thats some rock !!
73, Dick, W1KSZ
-Original Message-
From: Bruce Griffiths [EMAIL PROTECTED]
Sent: Jul 7, 2008 10:14 PM
To: Discussion of precise time and frequency measurement
John Miles wrote:
There is nothing special about the 5087A's amplifier cards. The 5087A
design is not especially quiet; in fact, it will degrade the broadband floor
of a Thunderbolt by a good 7 or 8 dB from what I have seen.
I'd say grab some PCB prototyping stock and a Dremel tool, and surf
Just watch for the odd error in those references.
eg in the first reference (.../498.pdf) the captions for figure 2 and
figure 3 should be swapped.
If anyone wants to try it, I have an even quieter, lower distortion 3
transistor isolation amplifier design that runs from a 12V supply.
John Miles wrote:
Just watch for the odd error in those references.
eg in the first reference (.../498.pdf) the captions for figure 2 and
figure 3 should be swapped.
If anyone wants to try it, I have an even quieter, lower distortion 3
transistor isolation amplifier design that runs from a
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