Re: [time-nuts] The clocks at Windsor Castle, UK

[Will Kimber]

And when those clocks were made there was no thought that in few
centuries time a system that decrees that the time be put forward and
back would be invented. They ran continuously and THAT was the time!

Will

On 06/17/2017 01:05 PM, William H. Fite wrote:
> The clocks at Windsor range from C14 wooden-geared pieces to French
> masterpieces of haute horlogerie with multiple complications including
> perpetual calendars, sidereal time, equation of time, true local solar
> time, date of Easter, various star charts and astronomical data, orreries,
> animated figures and other automata. The more exotic and delicate of these
> are not run continually but are started up periodically to test their
> operation and when the Royals wish to demonstrate them to guests.
>
>
> On Friday, June 16, 2017, jim stephens  wrote:
>
>>
>> On 6/16/2017 3:31 PM, Bob kb8tq wrote:
>>
>>> Hi
>>>
>>> They have been a novelty item just about as long as people have made
>>> clocks.
>>> Exactly what they do or do not have for adjustment capability would be
>>> very much
>>> a “that depends” kind of thing. There must be some method of getting the
>>> beast
>>> up to sync. It *could* be pretty involved.
>>>
>>> Bob
>>>
>> My father and I were @ a Costco quite some time ago and there was a very
>> nice clock with full Westminster chimes & moon phase. Drove the wife nuts
>> that we stood around fiddling with it to get it set properly and back in
>> phase with the other dials.
>>
>> One of those things that sticks in your gut sometimes if you're a time
>> nut.  My dad was my original time nut.  He found out that he could take
>> pocket watches apart when he was a kid and get them running again (1930s).
>>
>> Fathers Day plug as well.  Miss him a lot
>> thanks
>> Jim
>>
>>> On Jun 16, 2017, at 6:02 PM, Hal Murray  wrote:

 kb...@n1k.org said:

> One thing that may be missing is that the clocks involved also keep
> track of
> other things (date, lunar phase, sunrise / sunset …). Forcing them to
> gain
> or loose a day might mess some of that  up.
>
 I haven't worked with that sort of clock.  I would expect they would have
 some mechanism to set the clock back without damaging things.  Do they?


 --
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Re: [time-nuts] uC ADC resolution (was: Poor man's oven)

[Will Kimber]

For under $20 you can get a OCXO with Si5351A multi output oscillator
chip from QRP-Labs.


http://www.qrp-labs.com/ocxokit.html


No idea just how good it is but this link gives insight into how it was
developed.  Designed for WSPR radio transmissions.  GPS discipline can
be added.


http://www.hanssummers.com/ocxosynth


Cheers,

Will


On 06/08/2017 06:10 AM, Chris Albertson wrote:


> IT turrets out that you see MUCH more interesting designs when you lower
> the budget.  Anyone can make a high performance system even enough money.
> They waste half the cost on useless stuff and the product costs double what
> it should and is over complex but is works real, really well.   That's
> easy.  Harder and more interesting is "Can you make something just as good
> at 1/2 the price?"   Answer is usually Yes.  Then you say "what much do you
> loose if I set the price to 1/4?   The answer is surprisingly little if you
> get smart about sourcing parts.  Turns out about $180 is the minimum
> for pretty decent quality HiFi vacuum tube.
>
> An interesting graph would be Oven Specification vs. Price.  What is the
> minimum cost for keeping temperature to within 1.0 C, for 0.1C, 0.01 C?
>  Can you do 1.0C for under $5?   or 0.1C for under $10.I bet yes.
>
> I did an exercise a while back to see what is the minimum price and
> complexity to build a GPSDO that was good enough only to drive the lab
> bench instruments I have.   I implements only 1/2 od Lars W's design and
> cut his lines of code by about 90%.  Turns outhe cost is the XO and about
> $10.   Compared to my Thunderbolt, performance was not nearly as good but
> the ratio of performance over parts cost might be better.
>
>
>

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Re: [time-nuts] Measuring coax temperature coefficient with a TICC

[Will Kimber]

TV co-ax these days for satellite or UHF is almost all steel wire with
copper plating.  In fact the 'F' connector that is used is designed to
use that stiff wire as the center pin of the connector!


Will


On 04/20/2017 06:57 AM, Hal Murray wrote:
> kb...@n1k.org said:
>> I’d want to be pretty sure what the center conductor was made out of. 
>> I’ve
>> seen some stuff in coax that “one would think� should not be there 
>> (copper
>> over steel …). 
> Does that effect the propagation time?
>
> If I gave you a good scope picture of a pulse after going through chunk of 
> coax, could you figure out the ratio of copper to steel?  Would you need to 
> know the length or could you figure that out too?
>
>
>
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Re: [time-nuts] WWVB Simulator

[Will Kimber]

I came across this: " rpitx "  it is python software that enables a 
RaspberryPi to transmit using a GPIO pin.


The links refer to using the Rpi to produce 2m Tx signal.   Rpitx seems 
able to produce most modulation schemes. I have not tried it so have no 
idea if it would produce your need directly.


http://zr6aic.blogspot.co.nz/2016/11/creating-2m-fm-repeater-with-raspberry.html

http://zr6aic.blogspot.co.nz/2016/10/vhf-2m-low-pass-filter-design-for.html

Cheers,

Will


On 01/05/2017 09:53 PM, M. Simon via time-nuts wrote:

Paul,
The design of the  - wwvb cheatn d-psk-r - is an excellent start. It is why I 
wanted a WWVB simulator. There are some points that need improvement though. To 
cover the full range of a VCXO the current design might require (in theory) as 
much as a +90 to  -90 deg phase difference between the local oscillator and 
WWVB. I thought that should be reduced to +22.5 to -22.5 degrees ( in theory - 
actual will be less because the VCXO I'm using is active from about .5V to 2.5V 
instead of the full 0 to 3.3V). So that adds a voltage reference (for the 
offset),  op amp and offset resistors to the frequency control loop.

I'm also doing full surface mount (designed for hand soldering) and 
rationalizing the parts values. A fast CMOS comparator (instead of the clunky 
LM311) etc. Power required will be +/-12V and +5. Local regulator(s) will 
supply parts that need 3.3V. I'm designing with low cost in mind.

I still have a lot more work to do but the general outline is more or less 
complete. I will publish when I get some testing done.
The AM detector is also not like any other I have seen. It may be overkill. But 
it is not very expensive.

Simon
  Engineering is the art of making what you want from what you can get at a 
profit.
I like Polywell Fusion.
  


 On Wednesday, January 4, 2017 7:29 PM, paul swed  
wrote:
  
  


  SimonLike you I tend to like hardware. But today complete micros are so cheap and 
powerful they make life easy. Heck a bit to complex use 2 or 3. I like to follow the  
"Get-er-done" philosophy.
That said search the time-nuts archive for the wwvb cheatn d-psk-r. It knows 
how to create the bpsk time stream aligned to wwvb then flips a BPSK switch to 
remove the BPSK. This allows all of the old phase tracking receivers work 
without modifications.I used an Arduino $8 maybe and shared all of the details 
and software with the group. It preserves the old AM for radios that need that 
modulation.So a corrected wwvb signal can be had for cheap and it works very 
well here on the east coast. As well as wwvb ever did.
Have fun and use whatever technology you like as you are the do-er, you get to 
choose.
RegardsPaulWB8TSL
On Wed, Jan 4, 2017 at 2:48 AM, Chris Albertson  
wrote:

You don't need to tie up a PC.It could likely output the WWVB
signal while it was also surfing the web and reading emails.   60KHz
is NOTHING compared to displaying a you-tube video

In fact I bet your 48MHz uP could directly synthesize the signal.
Look at the ratio of 48 MHz / 60 KHz.  The uP can execute about 800
instructions during one cycle of a 60 KHz courier. Your PC can do
a million operations during that same one cycle.



Sure. I considered software. But I'm a hardware guy. I like designing boards. 
The rig was designed to do amplitude and phase simply. The final design will 
have a $5 48 MHz microprocessor included. I'm using that one because of speed 
and memory. When that proves out I might redesign for a $2 24 MHz processor. 
Onesies prices at Mouser

Besides the hardware better illustrates the concepts than software. And I don't 
have to tie up a PC if I don't want to.

I haven't priced everything out yet because the design is not done. I'd be 
surprised if the cost was over $20 in parts for everything - power supply not 
included. PCB extra.

Feel free to send this along to the list if you are inclined.




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Re: [time-nuts] new year crashes

[Will Kimber]

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




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Re: [time-nuts] new year crashes

[Will Kimber]

Geoff

I have also noted the pips sound different and seem to recall an on air 
comment about using local time*.  The last pip is not always longer.


You have also got to watch out for them using off air Freeview satellite 
transmissions rebroadcast on normal radio stations!


Cheers,

Will

ZL1TAO

* Maybe from the Carter Observatory where the old solar transit was.  
I'm not suggesting that they use it still.



On 01/02/2017 12:46 PM, Kiwi Geoff wrote:

Will Kimber <zl1...@gmx.com> wrote:

If you listened to Radio New  Zealand National news New Year's day
morning you would have heard then stating there will be 7 pips at 1:00pm.

However there were only 6 !!! So what happened?

I was listening to both of the above events too, and agree with your
comments Will.

The following is just my "observations" over the last few years as a
keen RNZ listener, and so may not be correct to those in the know.

To my ears, there are two "types" of Time Pips:

The "normal" time pips sound like reasonably pure sine-waves of 1KHz,
and are always correct to my house standard, and would be derived from
the atomic clocks at:

Measurement Standards Laboratory
Callaghan Innovation
PO Box 31 310
Lower Hutt 5040
New Zealand

https://www.msl.irl.cri.nz/services/time-and-frequency

The "other" time pips sound different, they appear to be shorter in
duration and more like a square-wave at 1KHz than a sine-wave. I
assume they are locally generated at RNZ and are used when the
land-line to Lower Hutt is broken by road-works, earthquakes, or a
digger driver with a careless hand !

In the past I have detected the "other" time pips drifting by about
half a second per day, so I assume it's a relatively simple XO that is
used rather than a GPS which I thought would have been a better option
for a standby reference.

So my guess as to what is currently going on (for RNZ time pips) is
that they are using the backup system , which appears to be manually
set - and is yet to be manually set by a man!

Maybe someone who knows someone in RNZ engineering, can give a more
accurate picture than just my conjecture.

Regards, Geoff ( Christchurch, New Zealand ).
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Re: [time-nuts] new year crashes

[Will Kimber]

Andy,

If you listened to Radio New  Zealand National news New Year's day 
morning you would have heard then stating there will be 7 pips at 1:00pm.


However there were only 6 !!! So what happened?

Cheers and Happy New year,
Will
ZL1TAO

On 01/02/2017 02:07 AM, Andy ZL3AG via time-nuts wrote:

If so, they should think about adding the leap second on the night of the 2nd 
wednesday of January, or such a time when things are quieter around the world.

Do they add the leap second at the same moment in time throughout the world, or 
are the clocks here in NZ running 13 hours and 1 second ahead of those in the 
UK for half of Jan 1st?

On 2/01/2017, at 1:54 AM, Adrian Godwin wrote:


I wonder if someone wasn't ready for their extra second :

http://www.bbc.co.uk/news/uk-38482746
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Re: [time-nuts] New stuff in my Tindie store

[Will Kimber]

Hi Nick,


Sorry to rain on your parade.  A good idea BUT ...


As a new (45 years) New Zealander may I make a couple of suggestions 
that folks back where I come from and others across the pond forget.


The Pacific Ocean is large and very spread out.  So the Chatham Islands, 
though part of New Zealand are 45 minutes ahead of New Zealand time.  
That is a real nasty and unusual time change. Plus NZ daylight time 
being GMT +13


Next are the Islands making up Tonga.  To keep the day consistent with 
New Zealand, Australia, other Pacific Islands & Asia went to G.M.T. +13 
as its timezone  a few years back.


Cheers,
Will

On 12/27/2016 04:40 PM, Nick Sayer via time-nuts wrote:

I’ve finally added the power supply I’ve designed for the Thunderbolt. It’s a 
combined switching+linear design. It’s been running my own Thunderbolt for a 
while now. There’s a schematic on the store page and it can come with or 
without a 15W primary supply. 
https://www.tindie.com/products/nsayer/thunderbolt-power-board/

The second one will be up next week, and it’s a simple GPS clock. It has 7 seg 
LEDs for hour, minute, second and tenth of a second (the later is interpolated 
from the PPS). My educated guess is that the tenths are accurate to around 200 
µs or so (the zeroeth is probably much better). It has support for +/- 12 hours 
of timezones, 12- or 24-hour time display (with AM and PM LEDs) and DST for US, 
EU or Australia (or off). It can come as a board-only “quick kit” (surface 
mount components all done and programmed, through-hole left for you to do), a 
“quick kit” with a laser cut wood and acrylic case and plug-in power supply, or 
assembled (in the case, with the power supply). It has an SMA jack for an 
external antenna (that is not included). 3.3V is supplied for active antennas. 
Board-only quick kit will be $59.99, assembled $99.99. I’m just waiting for the 
inventory of boards to come in before I activate that store listing. But for 
now, there’s the Hackaday project page: h

ttps://hackaday.io/project/18501-gps-clock

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Re: [time-nuts] Q/noise of Earth as an oscillator

[Will Kimber]

Around mid 1978 a scientific magazine had an item on the shift of axis 
of the earth due to earthquakes.  Sorry but searching has not found the 
item. My, not to be  relied on memory, thinks that it was from the 
French Bureau International de l'Heure in Science or Scientific American


Cheers,
Will

On 07/27/2016 10:45 AM, Tom Van Baak wrote:

Hal Murray wrote:

I've seen mention that the rotation rate of the Earth changed by a few
microseconds per day as a result of the 2011 earthquake in Japan.  Does that
show up in any data?  Your recent graph doesn't go back that far and it's got
a full scale of 2000 microseconds so a few is going to be hard to see.


Right. The IERS graphs I posted are real measurements of earth rotation. The 
earthquake / tsunami numbers are theoretical calculations only; numbers far 
smaller than what can be measured.

A couple of guys at NASA have carefully modeled all of this and the predictions 
are quite interesting. It's just that the official NASA/JPL press releases, 
once filtered by the popular press, give the impression that these are 
worrisome or real measurable effects on the earth's rotation rate or axis tilt. 
Instead they are order(s) of magnitude below what can be measured, given the 
level of VLBI resolution or earth rotation noise.

Here are three recent press releases:

2005 "NASA Details Earthquake Effects on the Earth"
http://www.jpl.nasa.gov/news/news.php?feature=716

2010 "Chilean Quake May Have Shortened Earth Days"
http://www.nasa.gov/topics/earth/features/earth-20100301.html

2011 "Japan Quake May Have Shortened Earth Days, Moved Axis"
http://www.nasa.gov/topics/earth/features/japanquake/earth20110314.html

Google for Richard Gross and Benjamin Fong Chao for more information.

/tvb

- Original Message -
From: "Hal Murray" 
To: "Tom Van Baak" ; "Discussion of precise time and frequency 
measurement" 
Cc: 
Sent: Saturday, July 23, 2016 5:59 PM
Subject: Q/noise of Earth as an oscillator




t...@leapsecond.com said:

Earth is a very noisy, wandering, drifting, incredibly-expensive-to-measure,
low-precision (though high-Q) clock.


What is the Q of the Earth?  It might be on one of your web pages, but I
don't remember seeing it.  Google found a few mentions, but I didn't find a
number.

I did find an interesting list of damping mechanisms in a geology book.
Geology-nuts are as nutty as time-nuts.  Many were discussing damping of
seismic waves rather than rotation.

I've seen mention that the rotation rate of the Earth changed by a few
microseconds per day as a result of the 2011 earthquake in Japan.  Does that
show up in any data?  Your recent graph doesn't go back that far and it's got
a full scale of 2000 microseconds so a few is going to be hard to see.



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Re: [time-nuts] How can I generate a very clean 1 W signal @ 116 MHz ?

[Will Kimber]

14.5Mhz  doubled is 29.0Mhz right in middle of 28 - 30 Mhz where the 
output will be. Quite likely to give a "birdie"


Will..


On 05/31/2016 07:06 AM, Tim Shoppa wrote:

OK, it sure sounds like you want to use a commercial signal generator or
something. But a different take:

14.5MHz is a standard stocked crystal at Mouser, Digikey, etc. Three stages
of doublers with simple fundamental-reject filters at each stage get you to
116 MHz.

If you want to make it time-nutty, there's the NIST JFET "push-push"
frequency doubler we've talked about here in the past. I think you'll use
substantially smaller number of turns on the 116MHz stage than on the
14.5MHz end of the transformers.
http://www.ko4bb.com/~bruce/FrequencyMultipliers.html

Tim N3QE

On Mon, May 30, 2016 at 7:06 AM, Dr. David Kirkby (Kirkby Microwave Ltd) <
drkir...@kirkbymicrowave.co.uk> wrote:


I was thinking about designing a 2 m (144-146 MHz) ->HF (28-30 MHz)
transverter, using a 116 MHz local oscillator feeding a level 30 mixer.

116 + 28 = 144
116 + 30 = 146

I'm wondering what's the best way to generate 116 MHz with very low phase
noise. Phase noise at < 20 kHz offset is particularly important, but 200
kHz would be fairly important. Outside that, it does not matter too much.

The ability to lock to 10 MHz would be "nice", but certainly not essential,
as absolute frequency stability would not be of prime importance. Getting
the phase noise as low as possible would be more important. I expect better
performance can be achieved if one forgets about locking the signal source
to something else, but I may be wrong.

An HP 8663A sig gen has <-147 dBc/Hz at 10 kHz offset, but I'd hope its
possible to produce something better than is possible in a commercial sig
gen that covers up to 2.5 GHz.

Dave
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Re: [time-nuts] Old xtal filter

[Will Kimber]

Hi,

Is that 100Hz por 10cps?  Seems like a CW filter for a 100Khz IF - Ex 
500Khz Marine RX?


Cheers,
Will

On 07/03/16 08:31, Joseph Gray wrote:

Assuming I made the pictures small enough, attached are two images of
an very old crystal filter that a friend found. The strange thing
about it is the bandwidth - 100 Hz. What could this have been used
for, with such a narrow bandwidth?


Joe Gray
W5JG


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