There is a 3G/4G Supplementary Downlink allocation at 1492MHz in some
countries. Close enough to cause problems.
Andy
www.g4jnt.com
On Mon, 11 Jul 2022 at 14:40, paul swed via time-nuts <
time-nuts@lists.febo.com> wrote:
> Skipp
> I am aware at least in the US that there is the
to be called
out to identify the problem.
Andy
www.g4jnt.com
On Mon, 11 Jul 2022 at 14:37, Lux, Jim via time-nuts <
time-nuts@lists.febo.com> wrote:
> On 7/10/22 4:19 PM, skipp Isaham via time-nuts wrote:
> > Hello to the Group,
> >
> > I'd like to get some op
The status flag in the $GxRMC message tells you if the unit is 'locked'
The PPS appears more-or-less when that flag goes from 'V' to 'A'
Andy
www.g4jnt.com
On Wed, 22 Jun 2022 at 14:23, Dave via time-nuts
wrote:
> I am using a NEO-6M to provide a PPS signal
Do you mean "even submultiples"? ie. even division ratios.
Andy
www.g4jnt.com
On Sat, 28 May 2022 at 21:11, Matthias Welwarsky via time-nuts <
time-nuts@lists.febo.com> wrote:
> Hi Rich,
>
> Only frequencies that are even multiples of the internal crystal frequ
Google (other search engines are available :-) DISHAL Filter Tuning
Very neat and quick way to tune up a filter using just return loss.
Doesn't even require a VNWA.
Andy
www.g4jnt.com
On Thu, 26 May 2022 at 16:40, Bob kb8tq via time-nuts <
time-nuts@lists.febo.com> wrote:
> H
"During sunrise"
Isn't it more likely to be due to changes in the ionosphere during
sunrise/set that causes the timing discrepancies. Any changes to the
antenna / LNA due to temperature will affect the reception of all
satellites so should cancel out.
Andy
www.g4jnt.com
On T
stable in frequency, and of course very close to 1575MHz where
patch resonates.
One such faulty antenna I had once jammed every other GPS receiver in the
house - although they were all the old 2nd generation type receivers of two
decades ago
Andy
www.g4jnt.com
On Sat, 2 Apr 2022 at 19:27, Lux, Jim
e
out, in order to be able to push out more energy in a hurry when, say,
frequency drops too much.
The operators of such systems will have to be mandated or incentivised to
run backed off at all times in case their extra capability is needed for
emergencies.
Andy
www.g4jnt.com
On Wed, 9 Mar 2022
eceiver to give the phase shift.
Andy
www.g4jnt.com
On Tue, 8 Mar 2022 at 14:55, Bob kb8tq wrote:
> HI
>
> > On Mar 8, 2022, at 2:31 AM, ed breya wrote:
> >
> > Just an interesting observation. Last night, shortly after I wrote about
> my dual GPSDO system, I decided
beat note, it's quite
feasible to have several instances of that software open at the same time,
all fed from the same soundcard source. Set each instance to a different
FFT resolution, one wide, one narrow and others as you like, and watch what
happens
Andy
www.g4jnt.com
On Mon, 21 Feb 20
/10MHz_Reference_Source_Stability.pdfand
http://g4jnt.com/ShortTermStabilityLeoBodnarGPSDO.pdf
I used synths I had to hand, but anything that will multiply up your test
and reference signals to a pair of frequencies separated by a few kHz, so
you can look at the beat note using soundcard software.
Andy
At that time the synth was set to one frequency and the code went into
sleep , so any buffering resistors etc would have served no purpose.
The TCXO really was hopping over four frequencies in a PN way at intervals
of a little under one second per hop.
Andy
www.g4jnt.com
On Sat, 19 Feb 2022 at
unded like a familiar
modulation on a synth that wasn't programmed to generate it. There were
four tones hopping in a (presumably pseudo) random manner, and the WSJT
mode I was going to use, JT4, had... four tones that hop around.
Andy
www.g4jnt.com
On Fri, 18 Feb 2022 at 10:19, Erik
sing other module types, GPRMC became GNRMC to cope with
Glonass etc. so that was another change needed.
Andy
www.g4jnt.com
On Wed, 9 Feb 2022 at 15:49, Bob kb8tq wrote:
> Hi
>
> In terms of upgrading the GPS module(s):
>
> You might want to look at just *what* NMEA messages are being
SDO.
All beacon details at scrbg.org
Andy
www.g4jnt.com
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Those diodes are so robust that a PIC connected the wrong way to a 5V 1 Amp
PSU was protected by all these diodes conducting in parallel and current
limiting the PSU. The PIC appeared to have survived (although I chucked
it anyway, just in case)
Andy
www.g4jnt.com
On Sat, 29 Jan 2022 at 18
n the PIC keep it to safe limits.
Andy
www.g4jnt.com
On Sun, 23 Jan 2022 at 10:44, Dave B via time-nuts
wrote:
> On 23/01/2022 08:30, time-nuts-requ...@lists.febo.com wrote:
> > Stick with the transformer. The use of a capacitive divider is
> predicated on the line waveform always
rates on landlines; on my mobile network '123'
gets voicemail.
Andy
www.g4jnt.com
On Fri, 7 Jan 2022 at 09:18, Bryan _ wrote:
> , and only after asking those on the "party line" to hang up, only
> those over 55 would know what I am talking about.
>
> -=Bryan=-
In the UK, the BT speaking clock, apparently, is still operational.But
at a cost of 50p per minute, I doubt it gets much use.
I'm not going to waste 50p by dialling 123 from the landline to test it
still goes, and it doesn't work on mobiles.
Andy
www.g4jnt.com
On Mon, 27 Dec 202
ng in mind this was in a temperature controlled environment is not as
bad as a Zener in open air
Andy
www.g4jnt.com
On Sat, 25 Dec 2021 at 16:26, Poul-Henning Kamp wrote:
> Being also a bit of a volt-nut, I played a bit with the Vref output
> from some of my OCXO's and must sadly repor
I've always assumed this is because they need to know the reference is
clean and under the OCXO manufacturer's control if it's to meet specs. If
the user had to supply the reference there's no knowing how clean it is.
Andy
www.g4jnt.com
On Thu, 23 Dec 2021 at 17:47,
any signal will have dropped below the noise and cannot be
considered to be "transmitted"
Andy
www.g4jnt.com
On Sat, 11 Dec 2021 at 16:11, wrote:
> Although not advisable a search of the Internet will turn up several.
> There is a well know Raspberry PI version. The range of th
Don't give up now, Jared! You must be so close to getting that puppy running
correctly.
On 2/12/21 9:16 pm, Jared Cabot via time-nuts wrote:
Well, yay...
I put the OCXO back in the 5065A, and got a good 2nd Harmonic reading. So I
started going through the alignment procedures and somehow I
On 1/12/21 5:03 am, Jared Cabot via time-nuts wrote:
Hopefully I can find something in Akihabara
Yeah yeah, don't rub it in! :^)
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Your push-pull doubler is much nicer than my full-wave rectifier with
Schottky diodes
http://g4jnt.com/10MHzDist.pdf
Andy
www.g4jnt.com
On Mon, 29 Nov 2021 at 15:42, Wilko Bulte wrote:
> For those interested, Dave PA5DOF and your's truly are working to get the
> doubler imple
I forgot the URL
http://g4jnt.com/10MHzDist.pdf
Andy
www.g4jnt.com
On Sun, 28 Nov 2021 at 18:39, Andy Talbot wrote:
> The way I look at short term stability is to multiply up to microwave
> frequencies then mix the two and look at the resulting beat note. The
> popular ADF435
instability in real time.
An example of the techniques used on a range of 10MHz reference sources can
be found here (I used a different Fract-N synth with a smaller setting grid
possible than teh ADF4351 can give, but the same idea applies)
Andy
www.g4jnt.com
On Sun, 28 Nov 2021 at 18:19, Erik
I would imagine there are already several caesium clocks on board the ISS,
anyway.
Don't forget there is a velocity component in relativistic time shift, as
well as gravitational, so using a moving platform like an aircraft or the
ISS complicated things a lot
Andy
www.g4jnt.com
On Sun, 2
top.
Tom, ah I see, so your delta H is much smaller than I'd assumed.
Coincidently the same as the height of Ben Nevis ASL - for which I
calculated ~20ns
Andy
www.g4jnt.com
On Sat, 27 Nov 2021 at 20:04, Hal Murray wrote:
>
> j...@luxfamily.com said:
> >> Was just specul
A leap second is due 31 December. I'm sure I've seen reference to a "leap
second pending" flag in some reference to time keeping somewhere.
Andy
www.g4jnt.com
On Sat, 27 Nov 2021 at 15:23, Steven Sommars
wrote:
> FYI.
>
> At 2021-11-27 00:00:00 UTC many public
in g = 9.81 m/s² and h = 4300m for Mt Rainer gives an
expected value of 4.7 * 10^-16.
Over 2 days, 2 * 86400s, that would be 81 ns in total, four times your value
What am I missing?
Was just speculating what Ben Nevis at a mere 1340m height might offer
And
ideal, but could maintain a crystal more on frequency that just
open to the the air temp.
Perhaps used on a watch crystal thay would work more effectively.
Not sure where you'd get them from now, though.
Andy
www.g4jnt.com
On Fri, 26 Nov 2021 at 16:46, David G. McGaw
wrote:
> But not in
from 10MHz, four 74AC390 CMOS counters will do it
Or am I missing some fundamental issue here?
Andy
www.g4jnt.com
On Mon, 22 Nov 2021 at 18:20, Gerhard Hoffmann
wrote:
>
>
> Am 22.11.21 um 18:31 schrieb Erik Kaashoek:
> > Some time ago I needed a output at 10,00.001Hz s
choose your buffer
length, then make sure you get one that allows an exact integer division
from your clock. If you can't choose a buffer length and are forced to
take a fixed value, then frequency generation errors are inevitable.
Andy
www.g4jnt.com
On Mon, 22 Nov 2021 at 17:14, Jeremy
Could the Rigol be using a DDS / NCO lookup approach to its frequency
generation? In which case you'll be subject to rounding errors on the DDS
increment, whose maximum magnitude will be dependent on the register
length.
Andy
www.g4jnt.com
On Mon, 22 Nov 2021 at 16:53, Jeremy Elson
up to one minute after they happened.
Andy
www.g4jnt.com
On Mon, 22 Nov 2021 at 10:42, Hal Murray wrote:
> time.isan...@gmail.com said:
> > but I am curious to see if I could sync up with some of you guys who
> seem to
> > have some pretty cool set-ups.
>
> GPS has tak
ownload is given.
Andy
www.g4jnt.com
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to be aiming at -100dBc - but that woul dbe
impossible to measure with any test equipment I have. Even seeing -80dBc
was a challenge.
Andy
www.g4jnt.com
On Thu, 11 Nov 2021 at 00:53, Gerhard Hoffmann
wrote:
>
>
> Am 10.11.21 um 23:56 schrieb B Riches via time-nuts:
> > Any ideas on
Well, yes. No one would rely on a windows PC for timing accuracy, surely
This is what I did to get a fully coherent timing and frequency locked
system for a narrowband LF receiver using an FTDI interface to a PC.
http://g4jnt.com/Coherent_LF_Receiver.pdf
Andy
www.g4jnt.com
On Fri, 5 Nov 2021
lel access that 'looks' to the PC like a
serial port. Never tried this myself, but a number of manufacturers have
implemented PC interfaces using this route.
Andy
www.g4jnt.com
On Fri, 5 Nov 2021 at 18:32, Andy Talbot wrote:
> Use FTDI USB serial ports - you can't
ed in, a new COM
port is set up.
Andy
www.g4jnt.com
On Fri, 5 Nov 2021 at 18:26, Alec Teal wrote:
> A friend of mine who lives and breaths this stuff (I wont tell you what
> he does - but suffice to say he's authoritative) basically said to me on
> something about serial ports that
When things get that big they could put a series of location satellites
around the Moon, so it has its own ... err... not GPS, but MPS perhaps?
Andy
www.g4jnt.com
On Wed, 29 Sept 2021 at 15:31, Chris Howard wrote:
> My employment involves the design and manufacturing of construct
n hammered into an oval can support TE01
modes reliably enough if you need to suppress polarisation rotation.
Andy
www.g4jnt.com
On Mon, 20 Sept 2021 at 18:14, Andy Talbot wrote:
> What's the exact resonance frequency of ammonia? To as many sig figures
> as it's been calculated
What's the exact resonance frequency of ammonia? To as many sig figures
as it's been calculated.
Googling just seems to throw up "approximately 23.8GHz"
Andy
www.g4jnt.com
On Mon, 20 Sept 2021 at 18:10, paul swed wrote:
> Well at the very next MIT flea I will gra
So the 2 things you're after are thermal insulation and vibration insulation?
Digging can be expensive, and you have to worry about water table in many
locations.
How about the thickest concrete water tank you can find, plonk it in a nice location,
spray layers of polyurethane foam over the
Hence my observation that balanced twisted pair might be a better solution
than coax for 10MHz distribution
Removes all possibility of ground loops
Andy
www.g4jnt.com
On Sun, 29 Aug 2021 at 15:22, Dana Whitlow wrote:
> I believe that a significant problem in my case was not leakage thro
raft of ICs support the medium, from
RS422 to CAN bus drivers and receivers.
Andy
www.g4jnt.com
On Sat, 28 Aug 2021 at 17:51, AC0XU (Jim) wrote:
> I am hoping that you can help me about a couple of things:
>
> 1) My time-nuts summaries sometimes appear unformatted and unreadable.
3m dishes.
Andy
www.g4jnt.com
On Fri, 20 Aug 2021 at 22:33, Gerhard Hoffmann
wrote:
>
> Am 20.08.21 um 22:14 schrieb skipp isaham via time-nuts:
> >
> > Hello to the Group,
> >
> > I picked a box of used (removed from commercial radio APRS type
> > servic
fully pumped and ready to
go.
I replaced the NiCd battery pack which was completely dead when I got the
unit with a LM317 and float charged 24V lead acid batteries.
Andy
www.g4jnt.com
On Thu, 5 Aug 2021 at 23:26, paul swed wrote:
> Was talking with another time-nut on the best way to use th
So there's your good source impedance for the splitter 20 -
30dB RLoss without even considering the head amp itself.
Even several metres of UR43 should have enough loss to constitute a decent
match.
Andy
www.g4jnt.com
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I get a proper picture
Andy
www.g4jnt.com
On Fri, 23 Jul 2021 at 18:41, Dave B via time-nuts
wrote:
> From: Gerhard Hoffmann
>
> Subject: [time-nuts] Re: Tbolt
>
> > I can only offer an opened Morion MV-89A.
> > The 10 MHz version is really 5 MHz + doubler.
> &g
s@lists.febo.com -- To unsubscribe
> >> send an email to time-nuts-le...@lists.febo.com
> >> To unsubscribe, go to and follow the instructions there.
> >>
> > ___
> > time-nuts mailing list -- time-nuts@lists.febo.
If you're interested in the Short Term Stability of the LB GPSDO.
http://g4jnt.com/ShortTermStabilityLeoBodnarGPSDO.pdf
Andy
www.g4jnt.com
On Tue, 20 Jul 2021 at 18:12, Bob Darlington wrote:
> Same. He probably got 250+ requests in short order. I'm curious how the
> L
isolated by the diodes from all the other receivers. The
receiver delivering the highest antenna supply voltage would 'win' and end
up supplying the active antenna via its diode in the splitter.
Andy
www.g4jnt.com
On Wed, 2 Jun 2021 at 10:14, shouldbe q931 wrote:
> On Wed, J
More to do with amateurs using narrow band modulations, and the LB GPSDO
being moderately good close in. Phase noise out beyond a few kHz goes
more or less unnoticed on SSB
Andy
www.g4jnt.com
On Wed, 31 Mar 2021 at 13:35, Dana Whitlow wrote:
> Chris,
>
> It may be that the modul
>
> G3PLX did something similar, synchronising his GF clock to GPS. But
> wanting to make no modifications to the pendulum, IIRC he placed a
> solenoid near the pendulum and used eddy current loss to slow it down.
>
> Andy
> www.g4jnt.com
>
>
>
>
> <http:/
Well, I do everything in PICs with a assembler, but you have a point. A
flash memory chip is one route. An FTDI Vinculum and USB memory stick,
another.
Andy
www.g4jnt.com
On Wed, 24 Feb 2021 at 14:05, Dan Kemppainen wrote:
> Andy,
>
> Perhaps one of the little openlog units from
long term record of mains timing
error. You can download frequency from the Gridwatch site, but not
timing. And I wouldn't trust integration over such extended periods to
derive timing error.
perhaps it's time to add a serial output to my monitor and couple up an old
obsolete laptop
y and that is flagged. It's caught up now Mains timing is now just
0.7 seconds fast - and 2s of that was over the last hour or two.
Andy
www.g4jnt.com
On Fri, 12 Feb 2021 at 11:12, Andy Talbot wrote:
> I maintain a real time display of mains frequency, and the cumulative
> timing
It's still +47 seconds.Perhaps they'll correct over the weekend.
Wind generation is high at the moment, contributing 13.64GW to the 34GW UK
total demand (it it 22:100 as I write). Perhaps the high wind generation
level is the reason for the extended high frequency session.
Andy
www
Mine peaked at +50s earlier today, it may have gone higher but didn't see.
Now down to +44s.
There may be a longer term offset, since this monitor was set arbitrarily
265.3 hours ago, and who knows what the official offset was at that point
Andy
www.g4jnt.com
<http://www.avg.c
at audibly hums .
Andy
www.g4jnt.com
On Fri, 12 Feb 2021 at 18:06, Lux, Jim wrote:
>
> Maybe.. you've got to condition the AC from the secondary side of the
> transformer and use a pin to bring it in on, which requires at least 2
> or 3 passive components, and you alr
in, pass it though a three stage RC filter then into the
TMR1 input of a PIC 16F628 which has a Schmitt input at thresholds of 30%
and 70% of the rails. , ie 1.5 / 3.5V so plenty of hysteresis.
Andy
www.g4jnt.com
On Fri, 12 Feb 2021 at 16:57, Adrian Godwin wrote:
> I wouldn't be surp
average?
Andy
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2019 that caused frequency to drop
below 49.5Hz and initiate automatic load shedding; that happened over a
period of a couple of minutes but was a large scale problem.
https://www.ofgem.gov.uk/publications-and-updates/investigation-9-august-2019-power-outage
Andy
www.g4jnt.com
MRI machines use superconducting coils to generate a 1T magnetic field over
a volume sufficient for a human body
Andy
www.g4jnt.com
On Tue, 26 Jan 2021 at 21:47, Tom Holmes wrote:
> I was told that one of the killers of superconductivity is magnetic
> fields. I guess they '
You could mention it is roughly equivalent to the number of swings you get
for a weight on a rope before it stops swinging. Or something like that.
Andy
www.g4jnt.com
On Tue, 26 Jan 2021 at 13:14, Ole Petter Ronningen
wrote:
> Hi, All
>
> I am going to give a presentation to non-
e's a better write up in Jan 2021 edition of RadCom (RSGB Members'
magazine)
Andy
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day of week is simpler to visualise the error mechanism. Sunday is
transmitted as zero, Wednesday as 3. Two adjacent bits corrupted, so it
will pass the parity check.
Andy
www.g4jnt.com
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icate the wrong time for 58 seconds after midnight - I don't care about
that. Suppose I could do the GPS read and update at the :00 second point
which would repair leap seconds for all but the 23:59:60 interval, but it
'felt wrong' to do that at the time of writing the code.
Andy
Update.
The Junghans Mega is approx 100ms late updating its display. And it's
pretty cold, sitting in the outside shed so the LCD is a bit sluggish. It
looks like the designers of that tried to do the job properly.
Andy
www.g4jnt.com
On Sun, 27 Dec 2020 at 14:54, Andy Talbot wrote:
&
seems to get better reception out there. It's the only one that shows MSF
outages as it updates every hour - and the battery seems to last forever!
I never checked to see how close that is to GPS; if they implement proper
timing or just a simple delay bodge.
Andy
www.g4jnt.com
On Sun, 2
ith round ones with hands.Anyone else using domestic MSF or
DCF77 clocks who have observed this?
Andy
www.g4jnt.com
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when mains went off. I replaced those only two
weeks ago.
The only thing I've never tried is calibrating out local magnetic field
using Zeeman lines. Not having the Cs running continuously, I suspect
this would be a pointless exercise anyway, and the loss of a few parts in
10^-13 don'
Actually, diamond has five times better thermal conductivity than silver,
so is the most conductive element, although graphene is suspected to be
better still.
Andy
www.g4jnt.com
<http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_
pe of the curve at various
places along the plot tells you the cause of the error in the system."
Andy
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en I = S1 + S2 - S3 - S4
Q = S1 - S2 - S3 + S4 at 1kHz sampling, centred on 1kHz tone
See http://g4jnt.com/Coherent_LF_Receiver.pdf where the technique is used
in a coherent LF receiver.
Andy
www.g4jnt.com
On Sun, 25 Oct 2020 at 02:17, jimlux wrote:
> On 10/24/20 3:53 P
In days of yore + DOS, I implemented a GPIB control by bit-banging a
parallel printer port.
Those were the days
Andy
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<htt
Hz wobble) and very definitely
so at 24GHz and higher.
Andy
www.g4jnt.com
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ven one that is 'supposed' to be corrected from 'time-to-'time' Or Is it?
Andy
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me
free.)
Lloyd Blythen wrote:
... it's under active development, AD supports it very
> well, ...
That is somewhat debatable right now. But it's hopefully improving.
Regards,
Andy
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n a small change can put it over the top.
Andy
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Haven't been able to find anything so far. Can you post a hi-res pic of the
front of the system please?
On 7/09/19 10:17 am, Walter Shawlee 2 wrote:
I recently got a rack shelf filled with Symmetricom black modules (PMM
controller w/LCD display, GPS, PRS-RB Rb oscillator and PRS-XO ovenized
Attila,
How would you rate the HP E1437A VXI ADC for this application?
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separated by significant
geographical distances.
180-degree phase reversals and three-phase transformations along the chain of
information are easily distinguishable.
Thanks for your interest. I hope some will accept the technical challenge of
gathering data -- which is fairly minimal.
Andy
disturbances such
as rapid load changes or sudden generation adjustments, for example, it is
quite possible harmonic ripples could be propagated through the system.
Such effects could be observed by comparing phase data across significant
distances within a distribution grid.
Andy Backus
bout +/- 1 mHz
Gravity effects (looking at the front panel) --
rotation 90 degrees counter clockwise causes a 5.8 mHz decrease in frequency
rotation 180 degrees causes a 5.3 mHz increase in frequency
rotation 90 degrees clockwise causes a 12.5 mHz increase in frequency
A
reversible)
Andy Backus
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Alternatively, buy a suitably spec'ed BMS PCB from your favourite online parts site and
populate it with 18650 batteries recycled from "dead" laptop battery packs.
Total cost will be in the double digits.
On 9/03/19 11:14 AM, Bob kb8tq wrote:
Hi
For 100 to 120 AH at 13.4V you will pay in th
Brings to mind two interesting numbers:
I figured out when I was ten that it takes about 2 weeks to count to a million
at one number/sec.
Much later in graduate school I learned from an astronomer that a year has pi x
10^7 seconds.
Andy Backus
From: time-nuts
OK, now I'm sure the Dymec I mentioned earlier was not the same one as HP's
Dymec.
The Dymec I knew apparently got its name by condensing Dynamic Measurements
Corp. to Dymec Inc. Also the one I knew was much more recent than HP's
Dymec, which had been folded back into HP wel
back then. We had designed them into our test equipment.
I think the Dymec that made these, was located in Massachusetts, not
California, so it might not be the same company even though they both made
V-F converters and frequency measurement products. Maybe that was just a
coincidence.
ovides the
antenna current. I have found, as others have, that the frequency must be good
to several Hertz. So I use a crystal controlled CMOS gate oscillator to
generate the RF.
Andy Backus
WA2TND
From: time-nuts on behalf of paul swed
Sent: Saturday, Octobe
x27;t know yet if it
also lights up the neighbor's house. I think I will investigate that question
when (and if) they pull the plug in Colorado. But I am prepared.
Not so much for my La Crosse Technology WWVB BPSK clock. I think it will get
swamped out. Can't have everything,
.
Also -- when the GlobalTop loses a fix it still puts out the RMC sentence, just
without the lat and lon data. And the PPS immediately stops. I designed the
parsing scheme to account for that. How long that reporting would continue I
don't know.
Andy B
n the day of.
Andy Backus
From: time-nuts on behalf of Wayne Holder
Sent: Wednesday, September 5, 2018 3:01 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] WWVB Signal Generator
I've reworked my WWVB Simulator so it can
A good sextant with a good operator can measure apparent altitude to 0.1
minutes of arc. The fastest apparent motion of objects in the sky due to
rotation of the earth is 0.25 minutes of arc per second. So the best a sextant
can do with time (assuming accurate astronomical tables and an exact
WWV HF transmissions include a 100 Hz subcarrier that gives the info in cw
format.
For generating WWVB code I would suggest simply counting seconds to yield days
-- the WWVB code takes the day number in the year. Leap year is easy. Just
look up the DST start and stop.
acb
___
To answer Dana's question, there are many projects on the web (as Tom has
pointed out), but very few, think, will answer the question in total.
For the DYI person, I think a GPS module from Adafruit, an Arduino, and a
down-and-dirty little transmitter like mine or the one in Tom's second link
orientation of the
device's antenna. So I have one WWVB receiver in a good place and key my
little transmitter as a "translator" elsewhere in the house.
Andy Backus
From: time-nuts on behalf of Dana Whitlow
Sent: Friday, August 10, 2018 1:34 PM
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