Well, the latency in the php web page I posted earlier bugged the heck out
of me so I redid it the "right" way:
http://www.ko4bb.com/js/clock/?tz=America/Los_Angeles,Europe/Paris,Asia/Novosibirsk
Now the web page loads a Javascript program that uses the local machine's
time, the internet is only
For reference, my original Thunderbolt Monitor had a 3.3V CPU (3.6V max)
and a "voltage regulator" from the 5V consisting of two silicon diodes in
series. That worked very well. The original kit still runs, 10 years later.
When Fluke.l (of eBay fame) copied the design, he saved the cost of the two
I do have a number of those and while slow and clunky, they work and are
well documented.
They are quite configurable and I have not come across a piece of equipment
I could not make work with one of those.
However, I would not recommend buying one (at any price) simply because
they are not
t;: " . $dt->format('d.m.Y, H:i:s') . "\n";
}
//echo $dt->format('d.m.Y, H:i:s');
$sec=1;
?>
On Sat, Jan 9, 2021 at 2:52 PM Didier Juges wrote:
> Mindlessly inspired by this thread, here the cheapest solution you could
> get (I believe
Mindlessly inspired by this thread, here the cheapest solution you could
get (I believe):
1) Buy a pre-paid Android phone for about $30 ($20 when they are on sale).
They have a surprising amount of functionality for about as much money as a
middle of the road Raspberry Pi.
2) Point the browser
Jim,
Not to sound greedy or anything, but if you have a Thunderbolt around, you
can use 4 of my kits and put them on different time zones :)
Didier KO4BB
On Thu, Jan 7, 2021 at 10:59 PM Lux, Jim wrote:
> I've got a shelf about 80cm long that I'd like to have 4 timezones
> displayed on.
>
> The
Just for reference, I have an HP5334 that is missing the entire display
assembly and it works just fine over GPIB. Try it, it would most likely
work.
Didier KO4BB
On Thu, Oct 22, 2020, 9:46 AM Mark Spencer
wrote:
> I am just curious how viable would it be to use a 531xx series counter
> with
>
> Re: thermistors
* Stability of the supply/reference voltage.
>
If the reference voltage is also the reference of the ADC, its stability
and precision are much less of a concern, noise will pretty much be the
only issue.
Didier KO4BB
>
___
I second the thermistor as the most "bang for the buck" temperature
measurement device.
My applications have not been time-nuts (or volt-nuts for that matter)
quality but even in the °C accuracy range, they are hard to beat.
Didier KO4BB
___
time-nuts
Some CATV distribution amplifiers have built-in 4 or 8 way splitters and
work over 60-900 MHz.
They are cheap enough that's it's worth trying.
Didier KO4BB
On Tue, Sep 15, 2020, 4:57 PM Poul-Henning Kamp wrote:
>
> jimlux writes:
>
> > For work, I'm looking to distribute 200 MHz to 44
Thanks for the link. I remember using MicroCap when it was a DOS program
that came on 5 1/4" floppies. I probably still have them somewhere.
It had its quirks but I remember also it had always been fast. I just
downloaded mc12 and played with it a bit. I think I might use it over
LTSpice, at least
If you can open the case, you should be able to locate the largest board
(if there is more than one) where most of the conventional electronics is
located and devise a way to keep that part of the case cool, with a fan, a
heatsink or both. The physics package is designed to run hot but if too
much
A long time ago I used a 74AC74 to prescale a 100MHz VCO down to 25, the
74AC74 was AC coupled to the VCO and the signal was a fraction of a volt.
Worked quite well.
Probably not time-nuts quality but in a pinch it did the job at the time.
Didier
On Sat, Jul 11, 2020 at 9:37 PM Alex Pummer
You can use one of the Silabs 8051 microcontrollers. They run one clock per
instruction (for the 1 byte instructions like NOP) so dividing by 81 should
not be a problem.
I use them extensively to make programmable dividers. My favorite small
package is a SO-14. They have much smaller devices but
Even more so when the cable is long, as it is likely to be with a GPS
receiver. The cable attenuation does wonders attenuating the effects of
VSWR...
Didier KO4BB
On Fri, Jun 5, 2020 at 6:30 PM Tim Shoppa wrote:
> Many of us use F connectors and 75 ohm CATV RG-6 coax for GPS antennas when
>
I just got a Teensy 4.0, OSHPark edition (it was $18 when I bought a set of
boards a couple of weeks ago).
I have not done anything with it yet but I am looking forward to.
I have not looked at the differences with the 4.1.
Didier KO4BB
On Thu, May 14, 2020, 5:15 PM Adrian Godwin wrote:
> I
Tantalum capacitors are known to occasionally short for no good reason.
Give them a reason and they'll be happy to oblige.
Things that can damage a tantalum cap in a hurry include excessive voltage,
reverse polarity, overheating (likely with hand soldering) and current
spikes.
If it were me, and
I personally have an MX-500P
I like that it turns itself off if you do not use it after a few minutes,
and it takes about 15 seconds to have the tip back into soldering
temperature, so there is no reason to leave it on any longer than you need
it then and now and the tip won't burn.
Tips and
If you want to build a simple pulse extender, the design linked below is
derived from the one in my TBMonitor kit:
KO4BB.com/getsimple/index.php?id=pulse-extender
It is not full featured like the one from TAPR but may be enough for your
needs and will cost you much less.
You can get the PWB
to hold a Nano VNA.
>
> 73, Dick, W1KSZ
>
> On Thu, Apr 23, 2020 at 7:12 PM Didier Juges wrote:
>
> > The new Thunderbolt monitor kits are available.
> > This one has a 32 bit ARM microcontroller, which allows for some
> > interesting features.
> > Informatio
The new Thunderbolt monitor kits are available.
This one has a 32 bit ARM microcontroller, which allows for some
interesting features.
Information at www.ko4bb.com
The matching Android app, aptly named TBMon, is available in the Play
Store. Note that you can play with the app without buying the
Perry,
Typically jitter is expressed in the time domain (so many ps peak to peak
for instance)
Phase noise is expressed as a power ratio in the frequency domain.
Otherwise they usually represent the same phenomenon.
Didier
On Thu, Apr 9, 2020, 6:29 PM Perry Sandeen via time-nuts <
Search for Wenzel in the Manuals pages on my web site
www.ko4bb.com
Didier KO4BB
On Sat, Apr 4, 2020, 5:25 AM Dana Whitlow wrote:
> What is a "Wenzel amp"? Are you referring to the broad line of amplifiers
> made by Wenzel Assoc?
> You sound like you've got some insight into what is inside
When you feed an electrical moteur with that, it sounds like a Harley
Davidson :)
It's a feature!
On Tue, Mar 31, 2020, 10:58 AM Mark Spencer
wrote:
> A few decades ago I was chatting with an electrical engineer during some
> down time during a long project in Canada. We started talking about
Charles,
I'll be glad to rename it more appropriately :)
What do you suggest?
Didier KO4BB
On Fri, Mar 6, 2020, 9:53 AM Charles Steinmetz
wrote:
> Taka Kamiya wrote:
>
> > I have an HP105B with a newer HP11801 oscillator. * * *According
> to archive, this particular update was never a
I have not looked at the manual but it could be as simple as plugging a
Prologix GPIB-USB controller and using John Miles' GPIB Toolkit control
software to send just the right command. I would not call that programming
but it would involve reading the manual... :)
Both tools are well documented
Well, I have an old EP-1140 EPROM programmer that may be able to but I do
not have the manual or the software for it.
Software was running under MS-DOS, maybe an early Windows version like 3.0
or 3.1 so it may well be old enough to support those chips.
I do have a modern TL866 II Plus but it does
Keep in mind that BLE and "classic" Bluetooth are completely different
animals. There is no "serial emulation" with BLE.
If you want to use Bluetooth modules to isolate serial traffic, I recommend
the JDY-30/31 modules. They are a much improved (and cheaper) version of
the HC-05 that you can get
I do not see any transformer in the outputs. Common mode noise is never
your friend in any kind of distribution amplifier. That would be my biggest
complaint.
Otherwise it looks each output has its own filter but there are two outputs
per amplifier, so isolation may not be great between shared
http://www.ko4bb.com/getsimple/index.php?id=manuals
On Fri, Dec 20, 2019 at 6:00 AM Christophe Huygens <
christophe.huyg...@kuleuven.be> wrote:
> (maybe better suted to hp-agilent but I am no longer there - apologies)
>
>
> Hi,
>
>
> is there any functional or spec difference between the HP
The only controlled experiment I am aware of was run by Mark Sims in March
2009 and he measured a 100% difference in PPS change per hour between the
old chip and the new chip in holdover in the same Thunderbolt. Big enough
to be statistically significant.
Maybe the Khalman filter does not want to know the crystal temperature and
is more interested in the ambient temperature which is better acquired away
from the internals, i.e. in the corner of the board. The oven regulates the
crystal temperature so if it does its job, there should not be too
a good result
> with NTP over wifi.
> >
> > I'm not sure if the 8266 has the same issue.
> >
> > Shame, because with the ultra low power processor you could do some
> interesting things.
> >
> > -David (AD7WZ)
> >
> >
> >
> > ‐‐‐ Orig
ure I saw Bob write that 5uS was his goal.
>
> I don't think anyone would claim that ordinary cheap WiFi can achieve
> consistent sub-millisecond variations in latency.
>
> Tim N3QE
>
> On Sun, Dec 1, 2019 at 5:06 PM Didier Juges wrote:
>
> > You should look at
This article indicates: " Average precision was measured (by comparison to
known-good time sources) with 1 ms, or 0.001 seconds "
On Sun, Dec 1, 2019 at 2:01 PM David wrote:
> I'd think one of the ESP32's would be a fine choice. They have some good
> power management options to wake up
You should look at latency. The ESP8266 has serial (SPI) flash and a
relatively small internal cache. When the chip needs to load code from
flash, that can take a while, compared to the 5uS target. Great for cheap
IoT stuff, not so great for time sensitive, in my opinion.
On Sun, Dec 1, 2019 at
and the tablet
will charge from the PC.
When you plug an accessory into the tablet, it becomes the master and it
delivers power to whatever is connected to it.
On Mon, Oct 21, 2019 at 9:06 AM Paul Moore wrote:
> On Mon, Oct 21, 2019 at 12:01 AM Didier Juges wrote:
> > One issue: once t
The interface from the FA2 is USB, so there is no need (and no way) to go
through a DB9. I recommend using an adapter to go from your tablet
(typically micro-USB or USB-C) to a USB-A socket, then use a standard USB-A
male to USB-B male cable going to the FA2.
One issue: once the tablet is
"Of course this is why I am a time-nut :-)"
I might say you graduated from the Advanced class with honors :)
Didier KO4BB
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to
HP8656 and spectral purity should not be used in the same sentence. I had
one and the best band is VHF where it may be usable for SSB or NBFM if you
are not too picky. It gets worse from there going up. The worst is the
lower band (HF) because it is actually the high band mixed down.
If it is sensitive to orientation, it is probably also sensitive to
vibrations, so mobile applications may be out of the question, depending on
your needs.
Didier KO4BB
On Mon, Oct 7, 2019 at 2:00 AM Mark Sims wrote:
> The first time that I tried to set the FA2 internal oscillator frequency I
That thread won't die :)
Getting back briefly on the crimp versus solder debate, I want to give my 2
cents experience based opinion on this. I have been designing hardware used
in military platforms most of my life, save for a few years at the start
doing space hardware.
A properly crimped
The BME series requires a fair amount of code to convert data from the
sensor into human readable data like degrees. I use the BME280 in some
applications.
Personally, for just temperature sensing, I found good old fashion
thermistors to be cheaper and more accurate than most silicon sensors
That's what I do too. I do use Power Pole for my ham stuff that draws high
current but for all the <2A 12V stuff the 5.1mm barrel connector with
positive center is hard to beat because I have so many power sources and
equipment already wired for it. I am not ready to rewire all the off the
shelf
Raspberry Pi has no display, no keyboard. If you add those, you far exceed
the cost of a 7" tablet and you still have a pile of stuff that barely fits
in a shoe box let alone in a decent looking enclosure and that you would
not want to leave on a table unattended.
A cheap Android tablet is hard to
Android tablets support serial com via USB. You need an adapter which
should be easy to find (google Serial Adapter for Android). Of course you
will need the right software at the tablet end to do what you need.
IOs does not support serial com natively (at least did not when I checked a
year or
I have a number of revisions of the John Vig tutorial in my Manual pages.
The most recent was sent to me directly by John but I am not sure if it has
the notes.
www.ko4bb.com
Go to Manuals and search for Vig
Didier KO4BB
On Thu, Sep 26, 2019 at 7:03 AM Chris Caudle wrote:
> On Wed, September
The actual offset value in this application is somewhat irrelevant.
Temperature stability of the offset voltage and bias current is. The 10811
met it's specs with the LM208 so there is no need to get a substantially
better part even though as you pointed out it is easy. My point was not to
use
ant noise to the
> 4nV/rtHz @10Hz preamp.
>
> Bruce
> > On 26 August 2019 at 13:52 Didier Juges wrote:
> >
> >
> > How do SuperCaps compare with electrolytics noise-wise?
> >
> > Didier KO4BB
> >
> > On Sun, Aug 25, 2019, 9:04 AM Gerhard Hoffm
How do SuperCaps compare with electrolytics noise-wise?
Didier KO4BB
On Sun, Aug 25, 2019, 9:04 AM Gerhard Hoffmann wrote:
>
> Yes, these electrolytic capacitors can produce ugly effects.
>
> The winner is clearly the cheap
>
> < https://www.digikey.de/products/de?keywords=1189-1056-ND >
>
>
> It is my understanding that the latest version of the RPi (Pi4) has a
native full speed Ethernet interface, not through USB.
I also read that it needs a heat sink.
Didier KO4BB
>
___
time-nuts mailing list -- time-nuts@lists.febo.com
To
Wow, what a well written article.
I have been using Cloudflare's DNS service since it was introduced.
Absolutely no issues whatsoever. These people are top notch.
I anticipate this new service will be as well.
Didier KO4BB
On Fri, Jun 21, 2019, 3:03 PM Marco Davids via time-nuts <
I know I want one. Whether I need one is a different story :)
On Thu, Apr 11, 2019, 10:06 AM jimlux wrote:
> And it does other stuff, of course..(like signal analyzer and spectrum
> analyzer)
>
>
> http://resources.rohde-schwarz-usa.com/c/fswp-bro-en-3607-209
>
> -172 dBc @ 1GHz carrier, 10kHz
The way I do it in my monitors is I convert the date to Julian date, add
1024 weeks and convert back to calendar. That automatically fixes the leap
years.
There is a fair amount of juggling depending on wether you want to correct
the GPS offset but doing it from a Julian date is considerably
Just so you know, the KO4BB.com site has been down since yesterday. For
some reason, my ISP decided that the old IP address must have been worn out
and decided I needed a new one. They forgot to update my DNS so ko4bb.com
is pointing to a lot of vaccuum.
I was on the road so I did not notice until
The very low phase noise requirements for a 3GHz generator really cuts down
your options while raising the price significantly. You may be better off
with two boxes if you can really reduce your requirements to what you need
as opposed to what you want.
Also, I am sure you have seen that the
Digikey reports as obsolete stuff they discontinue but that may still be
carried by the manufacturer or other distributors. It is not always a
reliable indication of the product's general availability.
Didier KO4BB
On Tue, Feb 26, 2019, 9:01 PM Bob kb8tq wrote:
> Hi
>
> If you go over to the
Hugh,
You must be the only one this ever happened to ;)
Didier KO4BB
On Sun, Feb 10, 2019, 7:06 PM Rice, Hugh (IPH Writing Systems) <
hugh.r...@hp.com> wrote:
>
> Putting things in writing and disclosing it to the public is a risky
> undertaking!
>
> Best wishes,
> Hugh
>
y
> leap seconds, so should I calculate Julian date from TAI or some other time
> reference not affected by leap seconds?
> At the moment, I calculate it from UTC and I am pretty sure that it is
> wrong, just not sure what else to do.
>
> On Sat, Jan 19, 2019 at 6:51 AM Didier
On Fri, Jan 18, 2019 at 11:00 PM Steve Allen wrote:
>
> This expression is no longer in use. It was superseded Capitaine et al.
>
> http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2003A%26A...406.1135C
> in which formalism it is explicitly disavowed that earth rotation is time.
>
>
with it but that's another
subject.
On Fri, Jan 18, 2019, 11:00 PM Steve Allen On Fri 2019-01-18T15:18:08-0600 Didier Juges hath writ:
> > //---
> > // Craig Haley 20/09/01
> > // 30-06-04 CSH made small changes
>
.
//---
// Craig Haley 20/09/01
// 30-06-04 CSH made small changes
// 05-01-05 CSH modified to use mjd rather than converting to jd
// Didier Juges
// 18Jan19 converted to C.
//---
/* original Mathlab code
Another option would be to phase lock the existing XO in the transceiver
instead of "replacing" it. With a very narrow PLL bandwidth, you should not
degrade the transceiver stock performance.
Didier KO4BB
On Wed, Jan 2, 2019, 4:17 AM Leo Bodnar Here is the phase noise at 10MHz
>
I have used that filter but with integer math it does not work well as
explained in this post:
http://www.embeddedrelated.com/showcode/304.php
The proposed algorithm at the end of the post is just as frugal with
storage and only marginally more wasteful of CPU cycles. It has the
advantage of
Not a time-nut issue but most banks that batch process will process the
debits before the credit so that they get to charge you no matter what.
They probably don't all do it but some definitely do. I had one bank even
charge me multiple overdraft fees because they processed the largest checks
Interestingly, Gregory just posted about his success with some FTDI
USB/RS-232 cables that are the real thing in a separate thread.
On Thu, Sep 6, 2018 at 7:03 PM Didier Juges wrote:
> Not sure what you refer to. I have made a large number of
> microcontroller-based Thunderbolt monito
Not sure what you refer to. I have made a large number of
microcontroller-based Thunderbolt monitor kits and they do not have that
issue.
In any event, a problem like this cannot be the fault of the Thunderbolt,
all it does is send data. It's up to the receiver to process it, including
properly
Congratulations Magnus, a well deserved reward for your contributions. My
boss is a Senior Member and I know they do not just give those away.
Well done!
Didier
On Thu, Aug 30, 2018, 3:40 PM Magnus Danielson
wrote:
> Hi Bob,
>
> On 08/30/2018 10:33 PM, Bob kb8tq wrote:
> > Hi
> >
> > Magnus …
Have you tried to contact the manufacturer? It sounds like something that
should be easy to fix and that he would want to fix.
Didier KO4BB
On Thu, Aug 23, 2018, 8:55 PM paul swed wrote:
> Hello to the group.
> Had sometime to hook up the chronverter wwvb simulator.
> Numbers of details.
> The
That's a very good point. I have used LEDs as photocells many times, the
first time was in 1974 when it was easier for this university student to
get LEDs than photocells.
I have also made a bi-directional optically isolated data link using a
single fiber optic cable and two fiber optic
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