This could be done with a LOT fewer chips. Two ways to go
1) All you need is a phase inverter controlled by a one bit signal
and an attenuator also controlled by a one bit signal and a small
micro controller. the small uP provides the two control signals. It
maybe gets time from a 1PPs
2) A
time-nuts@febo.com said:
> I have come up with a ridiculously simple WWVB simulator that simulates both
> the AM modulation and the BPSK modulation.
Did you consider software?
Is the audio on a Raspberry Pi fast enough?
I haven't looked at any details, but you can get ARM CPUs for ballpark of
I took a lot ok through the service manual, but didn't see the A7 schematic.
Is it someplace non obvious?
Thanks!
> On Jan 2, 2017, at 23:00, John Allen wrote:
>
> Hi Bob - I have a OCR'd service manual with schematics. There is also one on
> the KO4BB site
> http://www.ko4bb.com/getsimple/
I once saw a mention that the only difference between a 5372 and 5373 was the
firmware. A guy sent me some 5373A rom dumps and I tried them in a 5372... no
joy. It could be the PALs on the CPU board are different... or the rumor was
incorrect.
___
ti
Hi Bob - I have a OCR'd service manual with schematics. There is also one on
the KO4BB site
http://www.ko4bb.com/getsimple/index.php?id=manuals
I can post mine if that one isn't sufficient.
Regards, John K1AE, Bolton, MA
-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo
I have had an XL-DC at work since about 1997, serving as a reference
clock for an NTP stratum 1 server. My memory is getting fuzzy, but at
some point (after I called and asked) Truetime mailed me at no cost a
new ROM of some kind and a tool to cahnge it to deal with the W1K bug.
I think that just
Fwiw, an xor gate would make a simple bpsk modulator, carrier input A
modulation B, B is low A is buffered, when B is high, carrier is inverted
(180 degree phase shift).
On Mon, Jan 2, 2017 at 7:20 PM David wrote:
> I see generally how it should work but did not draw out a truth table.
>
>
>
> W
I have the CPU board 05372-6007 out of my 5372A this evening to replace the
battery. While looking at it, I see jumpers for 64/256K and 512k/2M.
I suspect the 64/256 is for the RAM as it is located next to the (non socketed)
RAM.
Does anyone have a schematic or listing of what all the jumpe
I see generally how it should work but did not draw out a truth table.
Why use the 74CB3T3253 instead of a low voltage 4052 variant?
It think you could buffer just the two references and save two
operational amplifiers and 2 or 4 capacitors.
On Mon, 2 Jan 2017 21:18:12 + (UTC), you wrote:
>
Hi again Joe,
Yesterday was 2 Jan. Which was GPS week:day 1930:2. Walk back 1024 weeks
and we are in 906:2. Monday in GPS week 906 was May 19th 1997. And that
was also the 139th day in 1997. And I think we can confirm the cause of
your problem.
How to fix it... the GPS receiver module beeing 20+
and if you glue a piece of non-magnetic material -- which could hold
that connector -- it could be even some plastic, to the surface of the
mu-metal , you do not need to worry about disturbing the magnetic conditions
73
KJ6UHN Alex
On 1/2/2017 3:44 PM, Attila Kinali wrote:
On Tue, 03 Jan 2
On Tue, 03 Jan 2017 11:02:54 +1300
Bruce Griffiths wrote:
> Maybe a waterjet cutter would imapct less on the shielding properties of
> tthe mumetal?
I doubt it. mu-metal is pretty sensitive to vibration as well and a
waterjet creates plenty of that. But anealing mu-metal is pretty simple,
if o
Hi Joe!
The Gps receiver module inside the XL-AK could have been hit by the 1024 week
problem.
Do the XL box have a display showing date/year? What does that show?
-- Björn
Sent from my smartphone.
Original message From: Joe Pendergrass
Date: 02/01/2017 23:29 (GMT+01:00) T
The number for the fiber is accurate.
However, fiber isn't laid straight path. I add at least 40% as a
precaution, as if laid on the sides of a square, where the original path
is the diagonal. This is however a very conservative measure to real world.
However, equipment delays can be much lar
Hi
My biggest concern is that they magnetize the shield as they drill it. It’s a
“static” field, but
it’s a static *near* field. I doubt that is a good thing ….
Bob
> On Jan 2, 2017, at 5:53 PM, Bruce Griffiths
> wrote:
>
> One could always wrap the assembly with its impaired mu metal shield
Hello, all. I am a new member, having discovered this forum a few days ago,
whilst doing a Google search looking for current telephone contact
information for TrueTime/Symmetricon technical support.
For many years I've had a TrueTime/Symmetricon Model XL-AK GPS time &
frequency receiver in serv
I have come up with a ridiculously simple WWVB simulator that simulates both
the AM modulation and the BPSK modulation.
A simple explanation and a link to the core schematic can be found here:
http://spacetimepro.blogspot.com/2017/01/wwvb-simulator.html
I'm working on fleshing out the design an
On 2 January 2017 at 18:21, Robert Atkinson wrote:
> I've a spare knob and it's on it's way to Dave. f
>
Cheers Robert. I'll send you some money. Drop me a private email with your
PayPal address.
> 5370 counters do seem to run hot so I don't think you have a fault. As
> suggested a little exte
One could always wrap the assembly with its impaired mu metal shield in several
layers of flexible magnetic shielding foil to regain the desired magnetic
shielding e.Most such foils can be cut with scissors without significant effect
on their magnetic properties.
Bruce
On Tuesday, 3 Januar
Hi
> On Jan 2, 2017, at 5:02 PM, Bruce Griffiths
> wrote:
>
>
> Maybe a waterjet cutter would imapct less on the shielding properties of
> tthe mumetal?
>
Maybe …. pretty good bet that the guys modifying these in their living room
aren’t focused on much more than getting them working as
Make that a dual rate moon camera.These were used to measure variations in
Earth's rotation period.
Bruce
On Tuesday, 3 January 2017 11:10 AM, Bruce Griffiths
wrote:
Carter did have a couple of small historic brass transit instruments which
were never used by them.They also used to ha
Carter did have a couple of small historic brass transit instruments which were
never used by them.They also used to have a spectroheliograph which was used.
Its long since been dismantled.Ther was also a lunar camera complete with
alodined aluminium plate.
Bruce
On Tuesday, 3 January 2017
Maybe a waterjet cutter would imapct less on the shielding properties of
tthe mumetal?
Bruce
On Monday, January 02, 2017 12:58:55 PM Bob Camp wrote:
> Hi
>
> > On Jan 1, 2017, at 7:31 PM, wb6bnq wrote:
> >
> > Hello Mathias,
> >
> > I think you did not quite understand how the calibration
Another one of those fascinating "threads!" I have lived through the claimed
110, 117 and 120 volt periods and have been apparently lucky enough to not have
suffered any device damage. At present I live on a hill and do worry about
lightning strikes to ham radio antennas. The last time I co
Apologies Bruce,
It is a good many years since I was there last.
Cheers,
Will
On 01/03/2017 12:40 AM, Bruce Griffiths wrote:
You mean the Dominion observatory surely not Carter. It was close by and also
had a Danjon Astrolabe.
Bruce
___
time-nut
It's not the fibre-it's the equipment on the end of it-specifically the
multiplex equipment. And with path switching where differing eqpt was used on
different links. you can guess the result!
Different technologies these days but the terminal eqpts, (where your packets
are injected/extracte
Corby
Congratulations on keeping the Maser going. Pretty amazing.
You should check it against wwvb to make sure its accurate. Chuckle.
Regards
Paul
WB8TSL
On Mon, Jan 2, 2017 at 2:42 PM, Tim Shoppa wrote:
> Very nice report, Corby!
>
> When I was in grad school back in the 90's, doing vacuum pum
Very nice report, Corby!
When I was in grad school back in the 90's, doing vacuum pump work was a
very menial task usually assigned to grad students, so naturally I became
quite familiar with it :-). Especially cleaning up messes with decrepit old
experimental systems!
I think back to those days
Happy Birthday EFOS2 Maser!
The EFOS2 active hydrogen Maser at my place just turned 34 years old!
Pretty impressive reliability.
It is an Oscilloquartz Maser, they are now called T4 Science.
I know a guy in Norway that bought the refurbished EFOS3 Maser last
year directly from T4 Science! It is 3
In message
, Tim Shoppa writes:
>What modern loads are actually sensitive to high (say, +10 to +20%) line
>voltage?
In EU you're supposed to have 230V +/- 6% in your outlet.
The way this was arrived at was:
A lot of europe used 220V +/- 10% = [198..242] V
Brittain used 240V +/- 10% =
What modern loads are actually sensitive to high (say, +10 to +20%) line
voltage?
Old incandescent light bulbs were among the most sensitive loads in the
past (so much so, that 130V light bulbs were commonly available from the
industrial suppliers).
I would naively expect the modern CFL's and LED
In message <586a8b40.4050...@erols.com>, Chuck Harris writes:
>Back in the dark ages of ~220V electrical distribution systems in
>Europe, the reaping due to unintentional grounding of a ~220V wire
>was so common and extreme, whole house ground fault interrupters
>were mandated for all re
Hi
> On Jan 1, 2017, at 7:31 PM, wb6bnq wrote:
>
> Hello Mathias,
>
> I think you did not quite understand how the calibration process works with
> that unit. The factory procedure is to set the pot to minimum and then bring
> the DDS up to the step that produces the closest frequency jus
It's not a split phase system in US residential power, it is a
center tapped 240V single phase system. Split phase systems have
historically had a 45-90 degree phase difference between the split
phases. The US system, depending on which wire lead you take as
your reference, has a 0, or a 180 degr
In my prior experience (from approx 5 to 20 years ago) actual wide area net
work links delivered over fiber from commercial providers could have latencies
of at least several times those figures. I seem to recall efforts were made
to lower latencies for applications such as stock trading but I
Happy New Year, Time-Nuts!
TAPR received the production run of TNS-BUF boards, and the engineering
sample of the TICC, from our contract manufacturer last week.
Both boards are nicely built and work as intended.
TNS-BUF boards will be shipping soon to those who ordered; some may
already have
On 2017-01-02 01:31, wb6bnq wrote:
Hello Bill
Thanks for your response and the pdf manual. There's lots of good
information in there. You are certainly right in that there's a
few things that I have not understood. Unfortunately this has not
changed after having read your response:
That "R"
Hal!
Good work!
On 01/02/2017 01:09 PM, Hal Murray wrote:
Here is data from a system using Google's NTP servers.
http://users.megapathdsl.net/~hmurray/time-nuts/leap/ntp-goog-leap.png
The Offset is the view from another system. The drift is from the system
itself.
Google said 13.9 uSec/sec
Leap second briefly catches out computer firm - Web firm Cloudflare was
briefly caught out by the leap second added to the end of 2016.
http://www.bbc.co.uk/news/technology-38488246?ocid=socialflow_twitter
Not the first, and won't be the last!
Happy New Year!
David
--
SatSignal Software - Qu
An Oscilloquartz 8660 is its equivalent... OK, slightly worse.
On Mon, Jan 2, 2017 at 12:05 AM, Bruce Lane wrote:
> Happy New Year, fellow time-tickers!
>
> Would anyone happen to have a spare MTI 240 series OCXO, 10MHz output?
> I'm looking to upgrade my TS2100.
>
> Failing the M
Here is data from a system using Google's NTP servers.
http://users.megapathdsl.net/~hmurray/time-nuts/leap/ntp-goog-leap.png
The Offset is the view from another system. The drift is from the system
itself.
Google said 13.9 uSec/sec. That matches the step in the drift.
Note the overshoot at
You mean the Dominion observatory surely not Carter. It was close by and also
had a Danjon Astrolabe.
Bruce
On Tuesday, 3 January 2017 12:10 AM, Hal Murray
wrote:
tract...@ihug.co.nz said:
> The 'landline' networks also have significant (and variable) latency. ISTR
> measuring a maxim
Hoi Mathias!
Wie goht's wie stoht's? :-)
On Sat, 31 Dec 2016 15:33:53 +0100
Mathias Weyland wrote:
> I'm new to this list. I got myself a FE-5650A Rubidium Standard off of
> ebay.
> It's the "option 58" 1 pps output variant, hence I have to modify the
> tuning
> word used in the DDS phase acc
tract...@ihug.co.nz said:
> The 'landline' networks also have significant (and variable) latency. ISTR
> measuring a maximum of around 400/500 mSec some years ago on a WN-CH digital
> link. Minimum over the test period of a week was nearer 250 mSec a few days
> later.
How can they get a delay
The 'landline' networks also have significant (and variable) latency. ISTR
measuring a maximum of around 400/500 mSec some years ago on a WN-CH digital
link. Minimum over the test period of a week was nearer 250 mSec a few days
later.
DaveB
ChCh, NZ
-Original Message-
From: time-nuts
On Mon, Jan 2, 2017 at 4:49 AM, Bill Byrom wrote:
> Most US homes and small businesses are powered by what is commonly
> called a "split-phase" 240 V feed. The final distribution system
> transformer has a 240 V center-tapped secondary. The center tap is
> grounded, and three wires are fed to the
The team I work with was forced to outsource the NTP service to a telco
(the largest in the Netherlands). Too bad they didn't handle the leap
second well.
Some time after the leap second hundreds of servers and VM's reported
NTP problems.
...
sys.peer - stratum 15, last reached 28 secs ago,
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