Having recently bought a couple of MV89As I found listed on AmazonUK I
received a feedback request a couple of days ago from the seller and took the
opportunity to point out that whilst one was fine the other was much
noisier than the first, and also in comparison with others I'd
Thanks Mate, I needed cheering up :)
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf
Of gandal...@aol.com
Sent: Monday, 1 July 2013 6:45 PM
To: time-nuts@febo.com
Subject: [time-nuts] Language -- The eternal barrier
Having recently
How do folks think that the Odroid/U2 might compare?
http://www.hardkernel.com/renewal_2011/products/prdt_info.php
More expensive than Raspberry Pi or BeagleBone black, but higher
performance?
Cheers,
David
--
SatSignal Software - Quality software written to your requirements
Web:
Hi
Is there a serial port on that board? NTP with USB serial is a bit clunky.
Bob
On Jul 1, 2013, at 6:57 AM, David J Taylor david-tay...@blueyonder.co.uk
wrote:
How do folks think that the Odroid/U2 might compare?
http://www.hardkernel.com/renewal_2011/products/prdt_info.php
More
I had a chance to go through the Time and Navigation exhibit at the
National Air and Space Museum last week. From a time standpoint,
there's probably not much there that time-nuts don't know already, but
it's kind of cool to see cleaned up examples of equipment from days gone
by. (there's an
Hi
Is there a serial port on that board? NTP with USB serial is a bit clunky.
Bob
===
Good point! I don't see one on that board, but the X2 has GPIO ports.
Getting more expensive again, though
Classic!!!
:-)
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of gandal...@aol.com
Sent: 01 July 2013 09:45
To: time-nuts@febo.com
Subject: [time-nuts] Language -- The eternal barrier
Having recently bought a couple of MV89As I
Hi
For a lot of what we do, having a board with 16 GPIO's and a couple of UART's
pinned out is probably more important than 1.2 vs 1.7 GHz on the CPU(s). A lot
of the Korean and Chinese boards seem to be aimed at driving a TV for streaming
video. All the other stuff is probably still there.
For those who are looking for a source of WWVB receivers / chips there
is a person in the UK who is selling the Symtrik board and antenna on
ebay -- item 23099171331. Unfortunately, the chip is embedded in expoy
but it does have a 1 pps LED. Here is the link to the data sheet:
For a few dollars LESS you can get an Intel dual-core Atom board. It is a
standard PC motherboard. These can run a file server, a web server, SSH
and NTP all at the same time and have about 90% idle time on the CPU.
(Running those other processes does not effect NTP.)
Yes but how much power do they use?
These arm boardjes are 5 watt, some even 1 watt.
On Mon, Jul 01, 2013 at 07:43:49AM -0700, Chris Albertson wrote:
For a few dollars LESS you can get an Intel dual-core Atom board. It is a
standard PC motherboard. These can run a file server, a web server,
Hal Murray said:
They make 74xU04 for many values of x. The U is for Unbuffered. They have
lower gain in the linear region.
I thought they were intended to be used for things like this, but I don't
understand that area. Can anybody give me a quick lesson or point me at a
good URL?
I always
For a NTP use the $40 ARM. The Atom is going to pull maybe 10W of power
but can do a lot more. I just did not see the use of the $90 quad core
ARM. It is over kill for NTP
I had my Atom running NTP, file server and inside a VMware virtual machine
Lady Heather to monitor the Thunderbolt GPS.
I have a WWII vintage octant used by my Dad to do celestial navigation
when ferrying bombers to England during the war. It was also used when
Colonial Airlines flew from NYC to Bermuda in the late 40's. Still have it.
It really is possible to navigate with the beastie. The airplane
Yes you could do nav with one of those. I had a sailboat for years (but no
now) My experience with celestial nav is that a novice is lucky to get
within 15 minutes of arc but some one who does it daily can be much better.
But even with 15 arc minutes you can find Hawaii.Today people expect
On Mon, Jul 1, 2013 at 10:43 AM, Chris Albertson
albertson.ch...@gmail.com wrote:
For a few dollars LESS you can get an Intel dual-core Atom board.
The systems aren't comparable. The Atom part you've mentioned is a
bare board. You have to add memory and mass storage to compare to a
Beagle Bone
Thanks. I didn't know there were two kinds. This is more useful for only
$5 more.
Loots like a good platform for porting Lady Heather. Any interest in
that. My idea is to have a web based GUI so you don't need a display or
keyboard. The ARM (or whatever) runs both NTP and LH and shares a
For those of us who would have to navigate a long way, there is a on-line
http://timeandnavigation.si.edu/
Robert G8RPI.
From: Jim Lux jim...@earthlink.net
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Monday, 1 July
Yes. They are not comparable. That was my point.
I think for what we are talking about here the $35 to $45 ARM boards are
best. No argument.
But for twice that (and about 10W power) you can have a real PC that can
run even VMware and Apache. To run that $80 Intel Atom board you would
need
Indeed. The Link A-12 sextant I have is shown on the page Navigation
at War
To take a reading, one rotates the plastic circular disk and puts the
object in the bubble. The markings are made on that disk as well.
At 12 o'clock, one can make out the pencil device that marks it. A
thumb
I am revisiting that tracking generator reference I brought up here a
while back, and trying to get my head around how a DFF can take the
difference between two frequencies. I have studied and thought about
the various topologies and conditions, and searched online for good
explanations, but
I suspect the threads been hijacked into a why doesn't email work.
I would say lets kill this thread.
Regards
Paul
WB8TSL
On Thu, Jun 27, 2013 at 5:35 PM, ed breya e...@telight.com wrote:
Hal Murray said:
They make 74xU04 for many values of x. The U is for Unbuffered. They
have
lower gain
On Mon, Jul 1, 2013 at 1:31 AM, David J Taylor wrote:
There is one write-up here:
...
for using the BeagleBone Black as an NTP server, but he seems to have an
offset of -0.281 ms from his PPS source, which is rather high.
It happens. Particularly if the discipline is botched for some
I haven't followed this discussion, and I probably do not understand it well
enough to comment, but here goes, anyway.
Have you considered the situation of using two J/K flip flops and an AND gate
to subtract one bit stream from another? I drew up a circuit back in the 70s
and never tried it
On Sun, 30 Jun 2013 19:04:18 -0400
Bob Camp li...@rtty.us wrote:
Thanks Bob for the extra insight. The way sweeping works, won't a number
of additional runs help to re-melt the crystal and help ironing out the
dislocations in the crystal?
That's not the way it's done. One pass under bias,
Bob Camp li...@rtty.us said:
Since all of these boards run a fairly complex OS, we'd also need kernel
code to support them ...
Most OSes already have support for PPS capture on modem control pins so it
shouldn't be too hard to add support for GPIO pins. (I'm not claiming it
would be
In message 201306250015.r5p0fgej007...@mail6c40.carrierzone.com, ed breya wri
tes:
and trying to get my head around how a DFF can take the
difference between two frequencies.
Try first to think about what happens if you XOR the two
signals, then convince yourself that the DFF basically does
the
Although quite a bit OT, i would like to coment a bit on the topic of
application processor boards, as there seem to be a lot of handwaving
in this area.
On Mon, 1 Jul 2013 08:14:55 -0700
Chris Albertson albertson.ch...@gmail.com wrote:
Thanks. I didn't know there were two kinds. This is
Obviously we've been doing it wrong all these years. Here's 29 dB Noise
Reduction
http://www.basspro.com/RedHead-RTX-Folding-Earmuffs/product/94964/ for
only $29.99.
Mike
On 7/1/2013 3:45 AM, gandal...@aol.com wrote:
Having recently bought a couple of MV89As I found listed on
about $1/dB, it's a bargain :-)
Reagrds,
Jean-Louis
On 01/07/2013 22:56, Michael Blazer wrote:
Obviously we've been doing it wrong all these years. Here's 29 dB
Noise Reduction
http://www.basspro.com/RedHead-RTX-Folding-Earmuffs/product/94964/
for only $29.99.
Mike
On 7/1/2013 3:45 AM,
On 7/1/2013 10:47 PM, Attila Kinali wrote:
General rule of
thumb: if lots of people are using it, there is a better chance
to find good support for it. The Odroid/hardkernel boards are a nice
negative example in that regard.
Attila,
could you please comment a bit further on the Odroid
Hi
There's a gotcha with trying to anneal quartz. If you take it above the Curie
temperature, it'll twin when it comes back down. You will have random right and
left handed domains in the bar. Net result is that you can't get it hot enough
to heal any imperfections.
Bob
On Jul 1, 2013, at
Hi
Flip flops are sampling devices. All samplers can / do act as mixers between
the clock (sampling) frequency and the input (data) frequency. That's all
that's going on. Look at it like a mixer and it all makes sense.
Bob
On Jun 24, 2013, at 8:13 PM, ed breya e...@telight.com wrote:
I am
Hi
On Jul 1, 2013, at 4:02 PM, Hal Murray hmur...@megapathdsl.net wrote:
Bob Camp li...@rtty.us said:
Since all of these boards run a fairly complex OS, we'd also need kernel
code to support them ...
Most OSes already have support for PPS capture on modem control pins so it
shouldn't
I did a quick test using a modified Python script to measure the elapsed
time of several NTP round trips
http://code.activestate.com/recipes/117211-simple-very-sntp-client/
The script is run on the Atom machine, all of the servers are running
ntpd 4.2.6p5
1.6 GHz Atom, loopback: 8100 req/s
400
On 06/30/2013 08:34 PM, Bob Camp wrote:
Hi
U….. eer…..
Natural quartz is great stuff for making resonators. In many ways
it's better than synthetic quartz. About the only thing natural is
worse for is radiation. Natural quartz comes from all over the world.
Most of the US
Before anyone wastes his money on a BeagleBone, I suggest you join the
mailing list and read the hundreds of messages each day that pass
through, most of them citing problems, mostly with the Linux implementation.
Basically, the ancient implementation of Angstrom Linux is a POS. Just
barely
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