Re: [time-nuts] 4046 replacement

[Alexander Pummer]

but as I wrote a while ego ADI has a bit different chip which is free of 
dead zone and much faster, I used it for low phase-noise clock generator 
for 3,1Gb/s fiber optic systems of C-Cor/Comlux in the end of the past 
century, now I am on vacation and do not have my engineering note books 
with me, but 1) I already posted it in the past 2) I will post it again 
after I returned home,

73
KJ6UHN
On 5/6/2018 1:03 AM, Charles Steinmetz wrote:
See below for further information on working with the 4046/7046/9046 
PLL families, including must-have design tools for anyone designing 
with these devices.


I wrote:


The "flaw" in the 4046 is a dead zone around zero error in Phase
Comparator 2 (the PC one generally uses).


Magnus responded:


It is very bad indeed. Someone chose to use the 4046 to lock up a 155,52
MHz VCXO to a 8 kHz reference, using a 4046 as a core. The charge-pump
was then "accelerated" with a supposedly better charge-pump with a ton
of passives. Turns out that the dead-band was still there to haunt the
designers. The 155,52 MHz was further multiplied to become the 2,48832
Gb/s clock, and as they measured this they had problems with the
jitter/wander of it


Of course the dead zone was still there -- it is built into the 
4046/7046 phase comparator, and nothing you do after-the-fact can 
eliminate it (but see below re: linearizing the 4046/7046 phase 
comparator). Most of what is wrong with the circuit you describe above 
is simply bad system design, not any fault of the 4046.


While it is true that some people call the PC2 output of the 4064 a 
"charge pump," as a voltage source it is, at best, a very poor one. 
The 9046 has a real, current-mode charge pump with tri-state outputs. 
The attached charts show the difference in linearity [1].


There are tricks one can pull to linearize the PC2 output of a 4046 or 
7046.  In particular, (i) injecting current into the PC2 output node 
biases the detector away from the dead zone at the price of a static 
phase error, and (ii) instead of using a passive RC filter, run the 
PC2 output through the resistor to the virtual-ground input of an 
active filter, which effectively turns the PC2 voltage output into a 
bipolar current output.  Still, however, the 4046/7046 PC2 cannot 
overlap positive and negative steering pulses as the 9046 PC2 can, and 
the 9046 thresholds are established by a real voltage reference, so 
the 9046 will always be better than the best that can be done with a 
4046 or 7046.


I do not use 4046-type devices very often, but ever since the 9046 
became available I have used it exclusively in preference to the 4046 
and 7046.


Best regards,

Charles


[1]  The attached charts are taken from the Philips CMOS PLL 
Designer's Guide (1995), which is an absolute must-have for anyone 
designing with the 4046/7046/9046 PLL families.  List member Daniel 
Mendes pried the Guide and supporting files out of Philips a couple of 
years ago, and list member Oz from DFW hosts them on his site.  I 
cropped the pages of the Design Guide to eliminate the large white 
borders and re-posted it all as a zip file to Didier's site: 
. 
Enjoy!




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Re: [time-nuts] WWVB: measuring local 60 KHz noise

[Alexander Pummer]

tuned,[ fine-tuning with vari-caps remotely] large size frame antenna 1 
meter dia provides mV size 60kHz in the Livermore area in California 
from the Colorado WWVB TX

73
KJ6UHN
Alex

On 5/5/2018 6:17 AM, Ulrich Rohde via time-nuts wrote:
  
I am trying to use the 60 KHz for synchronization of a Rb receiver. The local NJ noise and the signal in dBuV are about the same with an active antenna, electric field.  A better solution might be a ferrite selective antenna, H field , if I find one.
  
73 de N1UL
  
  
In a message dated 5/5/2018 4:09:25 AM Eastern Standard Time, hmur...@megapathdsl.net writes:


  
  Review/background: I have an UltraLink 333 WWVB receiver. It didn't work.

Several weeks ago. a discussion here mentioned that the phone cable between
the main box and antenna needs to be straight through rather than the typical
reversed. That was my problem. With the correct cable, the meter shows
signal and bounces around such that with practice, I could probably read the
bit pattern. But it didn't lock up.

That was several weeks ago. I left it running. When I looked last night, it
had figured out that it is 2018. I wasn't watching or monitoring, so I don't
know how long it took.

I assume the problem is noise. Is there any simple way to measure the noise
around 60 KHz? How about not so simple?

Extra credit for a way that others nuts can reproduce so we can compare the
noise at my location with other locations.

Can any audio cards be pushed that high? I see sample rates of 192K, but I
don't know if that is useful.

I'd also like to measure the propagation delays on WWV so a setup for HF that
also works down to 60 KHz would be interesting.

--

The UltraLink documentation says the display has a slot for a C or H. The C is 
for Colorado and the H is for Hawaii. Did WWVH have a low frequency transmitter 
many years ago? The NIST history of WWVH doesn't mention it.

My guess is a cut+paste from a version that listened to WWV/WWVH.





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Re: [time-nuts] Weird Stuff Warehouse shutting down

[Alexander Pummer]

other surplus: 
https://www.google.com/search?client=firefox-b-1=lcl=qGDJWrDzBuXm5gKB3bmQDw=electronic+surplus+bay+area+ca=electronic+surplus+bay+area+ca_l=psy-ab.12...16142.25972.0.28698.14.12.2.0.0.0.228.1752.0j11j1.12.00...1c.1.64.psy-ab..0.0.00.qHdPqOyu4I8#rlfi=hd:;si:;mv:!1m3!1d406993.57669817575!2d-122.07998499435485!3d37.551234775823595!3m2!1i636!2i386!4f13.1


73

KJ6UHN

Alex


On 4/7/2018 4:03 PM, paul swed wrote:

Like most of you I also visited these places and have dragged back and
shipped lots of "Weird stuff". Even smaller parts through airport security.
The oddest thing was 3/4" cable TV hardline connectors and there was no
issue at all.
It always made it fun to go on a business trip to the area and always slip
a bit of time into visit the places.
There may still be two left at this point. Electronic Surplus Sales or ESS
and do not recall the name of the other. But do know its location be heart.
I can say that in the 70s they really had an effect on my overall career.
Piles of computer stuff and much else. Buy it by the pound. Think it was
Mikes surplus by the Oakland airport. Long gone and one up in Berkley.

There is one crazy place down in northern LA. Some what hard to get to but
my god the stuff. Overwhelming. They dicker also. Nothing like a tough
bargain was there 3 years ago.


On Sat, Apr 7, 2018 at 10:36 AM, Bob kb8tq  wrote:


Hi

Over the years, this has been the fate of a *lot* of surplus / goodie
outfits. They have
a “deal” on some property and that runs out. Sometimes it’s a sale with
the neighborhood
improving. Other times it’s the roof needing repairs and nobody sees the
need to do them
until it is way to late ….

Bob


On Apr 6, 2018, at 11:24 PM, Bruce Lane 

wrote:

Fellow techies,

   I'm sorry to report we're losing another surplus place. Weird Stuff
Warehouse, in Sunnyvale, CA, is closing its doors as of Monday, 9-Apr-18.

   It seems we have Google to blame. Here's Weird Stuff's final
newsletter, verbatim.

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

April 6, 2018

To Weirdstuff Customers,

Sadly, after 32 years in business, Weirdstuff Warehouse will be closing
its doors as of April 9, 2018. If you have been following the real
estate news for Sunnyvale you know that Google purchased a large amount
of real estate in the area including the building we have been leasing
for the past 22 years. We have been asked to vacate the building as soon
as possible, and in order to accomplish that task we are selling our
inventory and many of our assets to Outback Equipment of Morgan Hill.
The transfer of inventory and assets will take place on April 9, 2018;
at that time Weirdstuff Warehouse will cease to do business.

Even though Weirdstuff is closing we will retain ownership of the
Corporation, trademark, and domain names. We hope to handle these
entities and wind down the corporation before year end.

Many of you have been loyal customers for many years, and we have
enjoyed working with you. We thank you for your loyalty and business.

For more information, check out our website after Monday, April 9, 2018.

WeirdStuff Warehouse
384 W. Caribbean Dr.
Sunnyvale, CA 94089
(408) 743-5650
--

   Heh... So much for Google's favorite "Don't Be Evil" motto

---
Bruce Lane, ARS KC7GR
http://www.bluefeathertech.com
kyrrin (at) bluefeathertech dot com
"Quando Omni Flunkus Moritati" (Red Green)
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[time-nuts] Fwd: quartz / liquid nitrogen

[Alexander Pummer]

at low temperatures bipolar devices will have reduced gain

73

KJ6UHN

Alex



 Forwarded Message 
Subject:[time-nuts] quartz / liquid nitrogen
Date:   Mon, 2 Apr 2018 12:46:26 -0700
From:   Tom Van Baak 
Reply-To: 	Tom Van Baak , Discussion of precise time 
and frequency measurement 

Organization:   LeapSecond.com
To: 	Discussion of precise time and frequency measurement 





Has anyone tried running a quartz oscillator at liquid nitrogen temperatures: -196 
C (-321F, 77K)? It's probably impractical commercially, but maybe something of 
value to a time nut. Would that dramatically lower temperature improve phase noise 
& short-term performance? Is there a crystal cut that could be optimized for 77 
K instead of ~25 C (room) or 60 C (oven)?

If not Nitrogen, how about dry ice (-109F -78C)?

/tvb

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Re: [time-nuts] HP 117A for ship

[Alexander Pummer]

Hi Perrier,

do you have the antenna for it too?

73

KJ6UHN

Alex


On 2/27/2018 6:39 PM, Perry Sandeen via time-nuts wrote:

List,
I have a 117 receiver that I never got round-to-it.
The tag on the unit sayes one tube is weak.  I have at least one extra tube 
(6CW4 IIRC) and more likely two.
It's avaiable for shipping from 92220.
If interested please send an ORIGINAL email off list.
Regards,
Perrier
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Re: [time-nuts] Heathkit GC 1000 Most Accurate Question

[Alexander Pummer]

Hi Bill,

where are you located? since something like that, would be a perfect 
"therapy" for me, because I am always buying "all kind of junk" [my 
wife's opinion, but it is very close to the reality ] and after I fixed 
it and played with played with them don't know what to do with it...and 
it is true, well, if you are not to fare from me-- because of the 
shipping costs --- I am in the Bay Area in California, I could fix it 
for you


73

KJ6UHN

Alex


On 2/5/2018 8:19 AM, Bill Baker via time-nuts wrote:

I own a Heathkit GC 1000 Most Accurate Clock.  It's in terrific shape but not used for 
many years.  It has stopped locking up to WWV and sometimes freezes up.  Can any of our 
"nuts" repair it?  Anyone want to buy it?

Bill, w1...@aol.com
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Re: [time-nuts] Bye-Bye Crystals

[Alexander Pummer]

actually the process  started as Statek started to etch the crystals
http://www.statek.com/corporateoverview.php in 1970, and produces high
quality crystal since than.

73
Alex
KJ6UHN


On 3/13/2017 11:05 AM, Richard Solomon wrote:

I don't think it's as much the manufacturing process as it is procuring the

raw material.


73, Dick, W1KSZ


Sent from Outlook

From: time-nuts  on behalf of Adrian Godwin 

Sent: Monday, March 13, 2017 8:01:39 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Bye-Bye Crystals

The article mentions that the business started in his father's garage.

What minimal equipment would you need to make your own crystals ?


On Mon, Mar 13, 2017 at 2:11 PM, Van Horn, David <
david.vanh...@backcountryaccess.com> wrote:


Probably true for many things.   My current design has six crystals, and
exactly none of them could be replaced by an oscillator module.
Power and space considerations mostly.

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Re: [time-nuts] Vintage Frequency Measurement

[Alexander Pummer]

There was also one generator which you could tune to beat the frequency 
in question the generator was a frequency synthesizer without any 
digital part that was the famous Schomandl FD!  see here



 SCHOMANDL-FD1-FDM1 FREQUENCY METER,
 
https://elektrotanya.com/schomandl-fd1-fdm1_frequency_meter.pdf/download.html
 there they have the circuit diagram and a complete service manual
 also,  the circuit was not that complicated

a similar Dekadischer Service-Frequenzmesser 
FD100http://www.radiomuseum.org/r/schomandl_dekadischer_service_frequenzmesser_fd100.html, 
on which I worked to was made with solid-state components

73
KJ6UHN
Alex
[Dr. Alexander Pummer a former design engineer of Schomandl KG in Munich 
Bavaria/Germany]



On 2/12/2017 6:07 AM, Bob Camp wrote:

Hi

Counters go back at least into the early 1950’s. I started out with fully vacuum
tube (except for diodes) counters obtained as surplus in the mid 1960’s. They
used some odd gas filled triodes. Everything in them could have been on the 
market
in 1947. They were not a common thing until the late 50’s.

Prior to that (WWII era) the standard approach was to use a heterodyne frequency
meter. They could be quite complex. I once passed up a “deal” on one that spread
out over several rack cabinets. The idea was that you produced a beat against 
this or that
and then beat it again against something else. Ultimately a meter or scope 
showed
you the phase offset.

The heterodyne approach lived on in the era of the counter using a synthesizer 
as
the reference. The beat note went into an analog meter based audio frequency 
meter.
It allowed you do do cute things like servo to a target when grinding or 
plating something
to frequency.

One key thing to keep in mind: in the 1930’s it is rare to find a frequency 
spec that is
not stated in percent (with some zeros involved). A  tight spec was in the 20  
ppm
(or 0.002% ) range. The idea of a heated crystal as a reference was a “national
standards” sort of thing in 1935. The crystal industry as we know it today 
really only dates
back to 1939. Before that the number of producers and the volume produced
was *very* small.

Bob



On Feb 12, 2017, at 1:08 AM, Scott Stobbe <scott.j.sto...@gmail.com> wrote:

I was inspired recently coming across a Lampkin 105 frequency meter, as to
how  frequency measurement was done before counters.

Certainly zero-beating a dial calibrated oscillator, would be one approach.

Is there a standout methodology or instrument predating counters?
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Re: [time-nuts] low power, but quiet, oscillators

[Alexander Pummer]

hi Magnus, how about the effect of that cheap 2,7K on the active device 
if it is bipolar?


Greetings

Alex

On 2/6/2017 4:35 PM, Magnus Danielson wrote:

Hi,

On 02/07/2017 12:36 AM, jimlux wrote:

On 2/6/17 2:37 PM, Bob Camp wrote:

Hi

One of the most basic reasons for putting out > +20 dbm is that you
had a spec of -195 dbc / Hz for the noise floor :)

Some of these specs *are* a bit mutually exclusive.


Sure.. And to be honest, I'm not sure that some of the folks coming up
with paper requirements for these speculative low power transmitters are
aware of that.  They take dBc values from 1 Watt transmitters and assume
you can meet that with your 1 mW transmitter.



Then again couldn't you cool your oscillator.. that gets the T part of
the kT down lower 

Cool that puppy down to <1K and get 25dB noise improvement, eh?


Your 50 ohm termination resistor will be a great source of that noise.
For a narrow-band fixed signal you can terminate with whatever 
reactive network you feel confident with instead. If you match 
impedance well enough it will work fairly well. Some oscillators have 
far-out impedances far from 50 Ohm anyway so impedance matching is 
so-so and most of the noise comes from the termination resistor.


Besides, for the deep space stuff you have cheap access to 2.7 K or so 
anyway, right? :)


Cheers,
Magnus
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Re: [time-nuts] FE-5650A option 58 tuning word for 10 MHz output

[Alexander Pummer]

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 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 one has enough space to build a furnace in the backyard. All you have
to do is find a wall material that can withstand the 1000-1500°C annealing
temperature and which can be flooded with hydrogen is enough.

Flooding the furnace with hydrogen is not dangerous, as long as the
interior is completely flooded (no oxygen) and the hydrogen leaks
out at well controlled points, where it can burn off. There are
descriptions how to do that out there. The only problem is that you need
enough space around the furnace for the hydrogen flames to not cause any
trouble. Being outside also helps to prevent hydrogen build-ups on the
ceiling while initially flooding the furnace or shuting it off.


Attila Kinali


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Re: [time-nuts] Totally unrelated, but..

[Alexander Pummer]

Once upon the time, there were some "three legged" voltage regulators, 
which were very sensitive to the ESR value of the capacitor which was 
connected to their output. With to low ESR values they oscillated, [the 
oscillation was "inside" of the regulator, which became warm, or 
sometimes hot, because of the high AC output current feeding into the 
output capacitor]  that is actually logical since the dominant pole of 
the control loop is determined with that output capacitor. For noise 
critical application use one resistor -- 0,5 to 2,00 ohms -- serial with 
the output capacitor,  and use an inductor -- 200uH to 1mH -- with very 
low  -- 20mili-ohm to 100mili-ohm  depend how much voltage drop could 
you tolerate with the actual current load -- ohmic resistance serial 
with the output, and a large capacitor--- it could be even10uF -- with 
very low ESR value -- as low as available, ceramic multi-layer 
capacitors are the best -- after the inductor, at the load site -- that 
way the second capacitor is isolated from the output of the regulator,  
and will be not part of the feedback loop. If you have the luxury, to 
design your own regulator, separate the DC feedback and the AC feedback, 
that way you could keep the output voltage more stabile without oscillation.


73

KJ6UHN

Alex


On 12/7/2016 8:43 AM, Bob Camp wrote:

Hi

You probably have proven one of the most basic design truths: Parts will 
*always* oscillate just
outside the bandwidth of your test gear” :). A few other possible issues:

1) Something else is oscillating and it is simply interacting with the 
regulator in an odd way.
2) The oscillation / noise is at a very low level and it’s below your test 
gear’s noise floor
3) Testing stops the oscillation

Bob


On Dec 6, 2016, at 4:24 PM, Van Horn, David 
 wrote:

Lots of discussion on here about low noise regulation so someone may know what 
to look for.

I have a receiver which is getting a lot of interference from somewhere.
Antenna disconnected, interference still high.
After much poking around, we found that replacing a voltage regulator with a 
slightly different part cures the problem.
Running that section on external battery is also fine, so it appears the 
original regulator causes some problem.
We tried various batteries over a range of voltages within the chip spec, and 
couldn't make it have a problem.

I looked at the reg input and output with scope and spectrum analyzer, and I 
don't see anything that indicates excessive noise or oscillation.
The PCB layout is as tight as you could ask for. Fat tracks, lots of ground, I 
couldn't lay it out any better.
Replacing the input and output caps didn't change anything.
Replacing the input and output caps with parts that should be "better", like 
Johanson Tancerams or tantalums has no effect.

Just for laughs, we tried a number of different regulator chips, all new from 
the reel.
The parts with the quietest and with the most noisy specs caused problems.
One part, with a noise spec more or less in the middle of the spread is the one 
that works.

So what is it that a monolithic regulator (linear) can do which is not 
observable on a scope or SA, which would cause a receiver to think it's getting 
a signal or significant noise in band?
Everything else in the system is shut down, I am sure the regulator chip is the 
culprit, but so far I don't see how it's causing the problem.
I could just use the quiet chip and move on, but experience tells me that I'd 
just have problems again down the road.  That's voodoo, not science.


Ideas?



--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: 
david.vanh...@backcountryaccess.com

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Re: [time-nuts] Rohde & Schwarz XSD 2.5 MHz crystal gone bad?

[Alexander Pummer]

"that should cause lowering the frequency" and it will lower the Q of 
the crystal too, therefore it will need more drive!


73

KJ6UHN

Alex


On 11/20/2016 5:00 PM, Alan Melia wrote:
Michael a couple of wild thoughts, make sure there is no 500kHz there 
(this is the crystal fundamental and the maintaining circuit should be 
degenerative there. (Is it a Meecham Bridge?)


That sounds like a baseless IO GT valve (tube in US ) enclosure which 
was probably originally evacuatedhas the vacuum gone soft in 50 
years?I dont know how you would check, but I think that would 
cause a lowering of the frequency.


Alan
G3NYK

- Original Message - From: "Michael Ulbrich" 
To: "Time-Nuts" 
Sent: Sunday, November 20, 2016 11:49 PM
Subject: [time-nuts] Rohde & Schwarz XSD 2.5 MHz crystal gone bad?



Hi there,

I'm new to this list and have some interest in quartz crystal and
rubidium oscillators - GPS, NTP, PPS and "clock watching" in general ;-)

I snatched an R XSD frequency standard accompanied by an XKE frequency
controller. Found the manuals on KO4BB's site (Thanks a lot for that!
BTW there's a slight mix-up of pages in that some of the XKE pages have
found their way into the XSD manual).

My initial hope of a quick and easy restoration project faded a bit when
I looked at the XSD output frequency after heating up the oven. It was
off by about -1 * 10-5 and after cranking the fine tuning for some time
and having another look at the specs I realized that the frequency was
too far off to be dialed in by the fine tuning which only covers about
+/- 2 * 10-7.

Next step was to take apart the oven and check series capacitor,
oscillator and the crystal itself. I found that even the coarse
adjustment range of the cylindrical series capacitor (40 - 110 pF) would
not allow to pull the crystal to it's specified frequency. When
replacing the series cap by a ceramic and lowering the value to just
before the oscillation breaks down (about 10 pF) I managed to set the
oscillator frequency offset to  +2.5 * 10-6 at room temperature. But
even this will not suffice when taking into account that the frequency
will drop by a few parts in 10-5 (cf. XSD manual) when the oven heats up
to its operating temperature. I also checked some of the components on
the oscillator PCB which might have an influence on frequency but could
not find any fault.

The crystal itself is a disk of about 30 mm diameter mounted in a sealed
glass cylinder of about 38 mm dia. and 43 mm height. There is no socket
just 2 bare wires.. It does not show any visual signs of damage.
According to a reference given in the R XSD manual the crystal's
construction follows a publication from A.W. Warner "Design and
Performance of Ultraprecise 2.5-mc Quartz Crystal Units" in Vol 39,
Issue 5 of Bell Labs Technical Journal (Sept. 1960). According to that
it is an AT-cut 5th overtone design.

Now my questions:

a) Considering that this gear is about 50 years old, a "crystal gone
bad" situation shouldn't be that much of a surprise, right?  But could
there be any other cause of the "huge" frequency offset besides a bad
crystal? I would very much appreciate any idea that I could try to get
this baby back on spec.

b) if nothing else helps: Could any of you give me a hint about who
might be able to supply a spare crystal? I tried my directly reachable
contacts but unfortunately to no avail so far. Please consider that
similar crystals might also have found their way into other
manufacturer's constructions from that era - Sulzer, Racal, HP ... you
name it ...

Many thanks in advance!

Best regards ... Michael U.
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Re: [time-nuts] I love the smell of tantalum in the morning

[Alexander Pummer]

metcal has a "hot twizer " to remove SMD components it heats the 
component on both end


73

Alex


On 11/5/2016 12:55 PM, Hal Murray wrote:

t...@leapsecond.com said:

Having not done SMT before, how should I do it with minimal risk to the
very precious PCB. Or, what equipment should I use this as a good excuse
to buy?

If you can get at it, 2 soldering irons, one on each end, works reasonably
well.  When both ends are melted, just push the part out of the way.
Small/light things like 0805 resistors will frequently stick to one of the
tops by surface tension of the liquid solder.



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Re: [time-nuts] Prologix USB-GPIB Controller

[Alexander Pummer]

Once upon the time I designed some power-supplies, used parts from a 
sound name US company, they asked for $12.-- each  --it was long time 
ego -- the equipment supposed to built in Asia, the manager -- I was one 
outside consultant -- told me that we can not use that expensive parts, 
my Chinese colleague told, that I should not worry that part will not 
cost more than a dollar, at the end we got the parts for 57 cents in 
Hong Kong,  the manager was on the opinion that the cheap parts are 
counterfeit, therefore we opened  one expensive original and one cheap 
one; the silicon was identical, as the performance toowas it a 
perfect copy, or one original?, who cares it worked like the original, 
but much cheaper.


73
KL6UHN
Alex

On 10/10/2016 10:13 AM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote:

On 10 October 2016 at 09:35, Charles Steinmetz 
wrote:


Poul-Henning wrote:

And for voltage references, "pre-owned" is likely to mean "better".
Perhaps, but third-world recyclers are not known for gentle treatment
during the parts removal process.


I had some cheap ($10) GPS receiver boards shipped to me in a plastic
kitchen bag from yikunhk on eBay. 4 boards in the same bag, all scratching
each other. The bag was not anti-static.

There are all number of possible explanations of why boards can be made so
cheaply, when the ICs appear to cost more than the boards.

* The chips are counterfeit
* The chips are similar to what they are supposed to be, but have been
relabeled.
* They are made at the same factory as the real devices, on what I've heard
described as the "ghost shift", where they are not officially made, but are
the same devices.
* They are recycled.
* They are stolen.

It is anyone's guess once you start buying semiconductor devices from eBay.
Maybe you are lucky, maybe you are not.

You dramatically increase the probability a part is good if sourced from a
reputable source (e.g. RS or Farnell in the UK). That is not to say that
the parts are not counterfeits, as even the best suppliers can get caught,
but they are more likely to be ok.

I recently bought a supposedly original Samsung battery for my Samsung
Galazy S3 phone from a local shop. The phone had all sorts of issues with
this battery, so I concluded it was a poor counterfeit.  I thought I'd be
safe buying directory from Amazon (not a 3rd party), but on reading reviews
on Amazon, I was not convinced those were genuine Samsung batteries either,
so I did not buy from Amazon.

Eventually I bought a battery from the Samsung website. The phone now works
ok.  I don't know if  Samsung actually make the batteries themselves, but I
think I have a better chance of buying from the Samsung website than from
anywhere else.

I've had "Duracell" batteries leak. At one time I used to blame Duracell,
but now it has cross my mind whether they might have been bought on eBay
and were counterfeits. I can't recall where they were purchased, but now I
will only purchase batteries from sources I consider reputable.

Dave.
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Re: [time-nuts] TimeLab

[Alexander Pummer]

Hello Magnus,

I am a totally unerducated time nut better, to say; not time nut, just 
an old RF ingenieur,  and so I have trouble to understand how could a 
counter stop to count before it started to count. I case you would have 
a circuit, which would tell you which pulse came at first and start the 
counter regardless of which of the two pulse came first and the same way 
stop the counter regardless pulse came last, you could count out the 
time difference with the interval counter independently from the 
sequence the pulses,


Or you could use two counters and reverse the inputs at the second 
counter, thus one counter would show the positive error and the other 
the negative error.


73
KJ6UHN
Alex



On 10/9/2016 4:32 AM, Magnus Danielson wrote:

Fellow time-nuts,

I don't know if it is me who is lazy to not figure TimeLab out better 
or if it is room for improvements. I was considering writing this 
directly to John, but I gather that it might be of general concern for 
many, so I thought it be a good topic for the list.


In one setup I have, I need to measure the offset of the PPS as I 
upset the system under test. The counter I'm using is a HP53131A, and 
I use the time-interval measure. I have a reference GPS (several 
actually) which can output PPS, 10 MHz, IRIG-B004 etc. In itself 
nothing strange.


In the ideal world of things, I would hook the DUT PPS to the Start 
(Ch1) and the reference PPS to the Stop (Ch2) channels. This would 
give me the propper Time Error (DUT - Ref) so a positive number tells 
me the DUT is ahead of the reference and a negative number tells me 
that the DUT is behind the reference.


Now, as I do that, depending on their relative timing I might skip 
samples, since the counter expects trigger conditions. While TimeLab 
can correct for the period offset, it can't reproduce missed samples.
I always get suspicious when the time in the program and the time in 
real world does not match up.


I could intentionally shift the PPS output of my DUT to any suitable 
number, which would be one way to solve this, if I would tell TimeLab 
to withdraw say 100 ms. I might want to do that easily afterhand 
rather than in the setup window.


To overcome this, I use the IRIG-B004 output, which is a 100 Hz signal 
with a stable rising edge aligned to the PPS to within about 2 ns. 
Good enough for my purpose. However, for the trigger to only produce 
meaningful results, I will need to swap inputs, so that the PPS from 
DUT is on Start/Ch1 and the IRIG-B is on Stop/Ch2. This way I get my 
triggers right. However, my readings have opposite sign. I might have 
forgotten about the way to correct for it.


However, TimeLab seems unable to unwrap the phase properly, so if I 
have the condition where I would get a negative value of say -100 ns 
then the counter will measure 9,999,900 ns, so I have to force a 
positive value as I start the measurement and then have it trace into 
the negative. I would very much like to see that TimeLab would 
phase-unwrap into +/- period/2 from first sample. That would be much 
more useful.


I would also like to have the ability to set an offset from which the 
current zoom window use as 0, really a form variant of the 0-base but 
letting me either set the value or it be the first value of the zoom. 
I have use for both of these. I often find myself fighting the offset 
issues. In a similar fashion, I have been unable to change the 
vertical zoom, if I don't care about clipping the signal then it 
forces me to zoom in further than I like to. The autoscale fights me 
many times in a fashion I don't like.


OK, so there is a brain-dump of the last couple of weeks on and off 
measurement experiences. While a few things might be fixed in the 
usage, I wonder if there is not room for improvements in the tool. I 
thought it better to describe what I do and why, so that the context 
is given.


Cheers,
Magnus
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Re: [time-nuts] time-nuts Digest, Vol 146, Issue 35

[Alexander Pummer]

Sometimes rectifiers generating very high harmonics particularly if the 
rectifier  is used close to it's current limits. The reverse recovery 
time increases, therefore the current is conducted after the polarity 
change  for a very short time --until the now majority charge carriers 
sweeping out from the junction -- the turn off is very fast [ that 
effect is used by the step-recovery frequency multipliers] an the result 
is very high multiplied harmonics with substantial amplitude since that 
very narrow current pulse is produced by a crowbar across the first 
charge capacitor's voltage. If there is some wire, which have the proper 
length for on "output resonator " the high frequency source is perfect 
and the repetition frequency - which is the double line frequency could 
be heard with the spectrum analyzer's AM The demodulator.  The amplitude 
of the high frequency pulses is much higher as it displayed on the 
spectrum analyzer, but the spectrum analyzer will integrate --due to 
it's limited bandwidth --  and shows the average of the pulses. Why is 
that important? because these high level pulses could modify an 
amplifier biasing, and perhaps cause periodically repeating jitters or 
even kill the input of an amplifier. I run into that problem some forty 
years ego with output rectifiers of switching mode power supplies. If 
you look old circuit diagrams of power supplies you could find some 
small capacitors connected across the rectifiers, these capacitors 
taking care the "buzz" in the old radios.


73
KJ6UHN
Alex

On 9/18/2016 7:39 AM, hardy wrote:

Hello
I see that you are using E4406A for direct phasenoise measurement--your results 
are the same as with my E4406A and thunderbolt-but have no spurs.
I think it must be your powersupply for your thunderbolt that made those spurs.
Hardy

-Oprindelig meddelelse-
Fra: time-nuts [mailto:time-nuts-boun...@febo.com] På vegne af 
time-nuts-requ...@febo.com
Sendt: 18. september 2016 15:29
Til: time-nuts@febo.com
Emne: time-nuts Digest, Vol 146, Issue 35

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When replying, please edit your Subject line so it is more specific
than "Re: Contents of time-nuts digest..."


Today's Topics:

1. Re: Thunderbolt spurs on 10MHz output at 100Hz and   200Hz from
   signal. (Lars Walenius)
2. Re: Thunderbolt spurs on 10MHz output at 100Hz and 200Hz from
   signal. (Bruce Griffiths)
3. Re: Thunderbolt spurs on 10MHz output at 100Hz and 200Hz from
   signal. (Peter Marczinowski)
4. Re: Thunderbolt spurs on 10MHz output at 100Hz and 200Hz from
   signal. (Peter Marczinowski)
5. Re: Thunderbolt spurs on 10MHz output at 100Hz and 200Hz from
   signal. (Dan Rae)


--

Message: 1
Date: Sun, 18 Sep 2016 12:52:21 +
From: Lars Walenius 
To: 'Discussion of precise time and frequency measurement'

Subject: Re: [time-nuts] Thunderbolt spurs on 10MHz output at 100Hz
and 200Hz from signal.
Message-ID:



Content-Type: text/plain; charset="iso-8859-1"

What is the specification for the Spectrum analyzer? They don´t tend to be 
useful for OCXO measurments so is this especially good? Or is it only the 
Analyzer phase noise we see?



Lars



Från: David C. Partridge
Skickat: den 18 september 2016 14:43
Till: 'Bruce Griffiths'; 'Discussion of precise 
time and frequency measurement'
Ämne: Re: [time-nuts] Thunderbolt spurs on 10MHz output at 100Hz and 200Hz from 
signal.



I've just redone the measurement without the external attenuator and with 10dB 
attenuation set internally to the analyser.

The results are attached.

Dave

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bruce Griffiths
Sent: 18 September 2016 12:52
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Thunderbolt spurs on 10MHz output at 100Hz and 200Hz 
from signal.

The signal level is also very low.
Brue

 On Sunday, 18 September 2016 11:47 PM, Magnus Danielson 
 wrote:


  The phase-noise still looks fairly high. How do you measure this?

Cheers,
Magnus

On 09/18/2016 01:27 PM, David C. Partridge wrote:

Now that's interesting I just re-ran the measurement, and got a quite different 
result which is attached.  The spurs have GONE.

My only guess right now is that 

Re: [time-nuts] HP-105B Battery Replacement?

[Alexander Pummer]

if you deep discharge led acid batteries -- which are not made special 
for deep discharge -- you will have to replace them quite often, on the 
other hand Ni-Fe batteries you could short out, overcharge they are 
undisrtuktable that is the reason why they are not produced any more in 
the US, they do not fit into the American business-model, but phone 
companies, railway and aviation still using them, you could still find 
old electrical forklifts with Ni-Fe battery made by Edison Batteries in 
the sixties in the past century the batteries are still fine. Tudor -- a 
led-acid battery producer -- purchased Edison Batteries and closed down 
the formidable competitor


73
KL6UHN
Alex

On 9/15/2016 2:26 PM, Mark Spencer wrote:

Hi I've run my HP105B (with the old style oscillator) from AC power via a 
consumer grade UPS, 24 Vdc from a lead acid battery bank and briefly from the 
internal battery pack with out any notable changes in performance (that being 
said I can't measure phase noise so this observation may or may not be of use.)

I'm not to fussed over the internal Nicad pack and rely on an external battery 
bank in case I loose AC power for an extended time period.

During a two day outage my HP105B and FTS1050 ran nicely from a 100 AH battery 
bank but the batteries needed to be replaced shortly afterwards.

Sent from my iPhone


On Sep 15, 2016, at 11:13 AM, Jeremy Nichols  wrote:

Your point is well made. My question is: what happens to the quality of the 
output sine wave if I use anything other than a true sine-wave (i.e., 
expensive) UPS? Most of them these days produce a semi-sine wave (aka modified 
square wave) that may or may not play well with the 105B. Anyone have 
experience?

A external battery and appropriate chargers and cabling does sound like another good 
alternative. Harder to move around but I don't (yet) have such a need, only that the 105B 
stay "on" regardless of power failures.

Jeremy



On 9/15/2016 10:15 AM, Bob Camp wrote:
Hi

A bigger question becomes:

Do batteries inside equipment make much sense anymore?

These days, a UPS is often a standard part of a rack in an outage prone area. 
Powering
the “whatever” instrument off of the same UPS as the rest of the stuff is one 
obvious
answer.

The other answer is an even older approach. Use a battery bank that is external 
to all
the gear in the rack and tend it independently of each box in the rack. That 
way you have
a few very large cells to worry about rather than a whole bunch scattered 
about. Things like
lead acid that are impractical in a piece of gear are more of an option in an 
independent
battery box. A single charger / line supply makes it easier to invest in 
something with real
smarts in it. The advent of dirt cheap isolated switchers makes the conversion 
to instrument
voltages a lot easier than it once was. Pick a common voltage like 12, 24, or 
48V and run with it.

My answer to the frequency standard battery pack question has become “don’t do 
it”. It makes
them a *lot* lighter weight !!!

Bob

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Re: [time-nuts] HP-105B Battery Replacement?

[Alexander Pummer]

Hi Brooke,

sorry I have to disappoint you; Ni-Cd batteries do not use any acid, 
they have K-OH  kalium hidrioxid  [potassium hydroxide  for anglophone ] 
as electrolyte and they are normally very air-tide, and widely used in 
radios.


73

KJ6UHN

Alex

On 9/14/2016 4:45 PM, Brooke Clarke wrote:

Hi Jeremy:

It's a very bad idea to put any battery with acid in an enclosure that 
has electronics since if it vents the acid will etch the PCBs.
Guess how I learned this.  I got a great price on a Gibbs Frequency 
Standard because the oven no longer worked.

http://prc68.com/I/office_equip.html


Modern Ni-Cad batteries have much more capacity than older ones and no 
longer have a memory effect.  They are also very easy to charge, so 
why not just replace the old cells?




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Re: [time-nuts] Anybody want a Thunderbolt power supply?

[Alexander Pummer]

there are peoples and societies for whom the most important parameter is 
the price of the goods, and there are also some societies for them the 
most important is the proffit


73

Alex


On 8/31/2016 3:13 PM, Bob Stewart wrote:

Charles,
said: "So the answer is to bring crap to market because nobody will pay for 
something that actually does the job?"
I don't mean to cause offense, but is everything you don't like crap?  The 
reality is that whatever the market will bear is what determines what comes to 
market.  If you can find high quality goods on ebay that can be modified to fit 
your needs, then you win.  There is a substantial market that either cannot do 
those mods or would rather spend their time elsewhere.  So, what they're 
willing to pay is going to determine what's available for sale.

As an example, my cost for the Hammond box I use with my GPSDO, with finished 
end panels, is just under $60.  From that viewpoint, I shouldn't bother to make 
it, because a surplus unit can always be found for a cheaper price, as long as 
I'm willing to accept whatever unknown baggage (no schematics, unobtainium 
parts, no software, etc) comes with that surplus unit.
Bob
  -
AE6RV.com

GFS GPSDO list:
groups.yahoo.com/neo/groups/GFS-GPSDOs/info

   From: Charles Steinmetz 
  To: time-nuts@febo.com
  Sent: Wednesday, August 31, 2016 5:02 PM
  Subject: Re: [time-nuts] Anybody want a Thunderbolt power supply?

Bob wrote:



OTOH, how many time-nuts have any interest in paying for a power supply that's 
up to time-nuts standards?  It's really not easy to bring a small product to 
market at a small price.  Even if you completely discount the personal effort 
of design, construction, and marketing, there's the issue of packaging.  
Without a package, it's just an amateur effort not worth considering.  With a 
package, such as a Hammond box, the price moves into new territory and nobody's 
interested.

So the answer is to bring crap to market because nobody will pay for
something that actually does the job?

IMO, the answer is to accept that the small, "little gizmo" providers
simply cannot fulfill this need efficiently.  I provided one solution,
using a surplus device from a large supplier and fifteen minutes of
soldering-iron time.  Even if you buy a box for it, it won't cost much
more than the $25 the OP proposed (and maybe not as much -- the ones
I've made have cost less than $25 each).  (And note that the OP did not
propose a complete, mains-to-Tbolt solution.  The proposed solution
assumed an existing mains-to-12v supply.)

That is part (the essential part, IMO) of the "little gizmo" provider's
business model -- find niche markets where things made at that scale
provide *better* performance than the alternatives.  There are lots of
areas where this can be done, but also very many more where it cannot.
The "little gizmo" provider is well-advised to learn how to tell the one
from the other.

Best regards,

Charles


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Re: [time-nuts] SR620 Problem

[Alexander Pummer]

how fare are you familiar with electronic equipment troubleshooting? 
could you find components, test points if somebody would ask you for 
that? do you have some electronic test equipment e.g. multimeter, 
oscilloscope? --last year I helped somebody to fix one HP high-frequency 
generator just per e-mail back and fort and he was able to fix the 
equipment, if you are interested let me know


Regards
Alex

On 8/29/2016 4:41 PM, Don@True-Cal wrote:

Sure, my original post ask for anyone in the US as I live in Springfield 
Missouri but I will be happy to ship anywhere in the states. I have the 
complete schematics for the unit. Was hoping to find someone specializing in 
SRS equipment or already having repair experience with the SR620.

Regards,
Don

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Tom Miller
Sent: Monday, August 29, 2016 4:37 PM
To: Discussion of precise time and frequency measurement 
Subject: Re: [time-nuts] SR620 Problem

You might say where you are. Maybe someone lives close that can assist you.

Regards,
Tom

- Original Message -
From: "Don@True-Cal" 
To: "'Time Nuts Group'" 
Sent: Monday, August 29, 2016 5:17 PM
Subject: [time-nuts] SR620 Problem



Hello All,



Sorry if this is a repeat but not showing up in my sent mail. Changed the
list address slightly.



I'm looking for someone that has repair experience on the SR620 TIC. I
have
a failed unit that has previously worked perfectly for many years while
running continuously on my lab bench. The failure occurred after a very
dirty mains power failure during a storm. There was no other evidence of a
severe lightning strike so I suspect just a major power line glitch. I
have
a second unit so time to repair is not critical. I have checked and
confirmed all of the power supplies and eliminated all of the easy fix
scenarios already. The major symptom is absolutely no display of
indicators
or readout (unit looks to be off), -DROPOUT form the PS is ok. I believe
the
loss of LED and display is from the processor stopped U131B flop. I don't
have sufficient confidence, let alone spare IC to delve into the processor
chain. Is there someone in the US with this experience that I can send
this
unit to for repair. Being retired and all this just being a major hobby
makes repair cost a big concern.



Regards.

Don J.



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Re: [time-nuts] SR620 Problem

[Alexander Pummer]

Hi Tom, do you have circuit diagram for the unit?

73

Alex


On 8/29/2016 2:37 PM, Tom Miller wrote:
You might say where you are. Maybe someone lives close that can assist 
you.


Regards,
Tom

- Original Message - From: "Don@True-Cal" 


To: "'Time Nuts Group'" 
Sent: Monday, August 29, 2016 5:17 PM
Subject: [time-nuts] SR620 Problem



Hello All,



Sorry if this is a repeat but not showing up in my sent mail. Changed 
the

list address slightly.



I'm looking for someone that has repair experience on the SR620 TIC. 
I have

a failed unit that has previously worked perfectly for many years while
running continuously on my lab bench. The failure occurred after a very
dirty mains power failure during a storm. There was no other evidence 
of a
severe lightning strike so I suspect just a major power line glitch. 
I have

a second unit so time to repair is not critical. I have checked and
confirmed all of the power supplies and eliminated all of the easy fix
scenarios already. The major symptom is absolutely no display of 
indicators
or readout (unit looks to be off), -DROPOUT form the PS is ok. I 
believe the
loss of LED and display is from the processor stopped U131B flop. I 
don't
have sufficient confidence, let alone spare IC to delve into the 
processor
chain. Is there someone in the US with this experience that I can 
send this

unit to for repair. Being retired and all this just being a major hobby
makes repair cost a big concern.



Regards.

Don J.



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Re: [time-nuts] DIY VNA design, directional coupler

[Alexander Pummer]

there is a current mode feedback device [which does not follows the gain 
bandwidth product role ] and has 1000V/usec rise time 92dB THD at 30MHz  
3nV/rtHz noise, see here http://www.ti.com/lit/ds/symlink/ths4271.pdf, I 
used it as a medical color Doppler application


Guanella's choke and Guanellas balun are two different animals, the 
balun has a cross DC path, the choke does not have, it's other name is 
1:1 transmission line transformer,  in conjunction with an A/D converter 
the choke has the function to prevent a current path to the ground via 
one of the the differential inputs, also used in high dynamic range 
medical ultrasound application


73

Alex


On 8/21/2016 1:29 PM, Attila Kinali wrote:

On Sun, 21 Aug 2016 10:04:10 -0700
Alex Pummer  wrote:


directional coupler/circulator could be made with high bandwidth [ up to
1GHz ] operational amplifiers, that circulator will work from DC..

While this is a valid option, it would then become the element in the
system that limits dynamic range. It's better to use a "noiseless"
passive circuit that has very little distortion.

Also keep in mind that even if the opamp has an GBW of 1GHz or more,
the slewrate kicks in quite early and in this case would limit the
maximum signal strength severely. There is a reason why GHz amplifiers
use so much power.


driving A/D converter input asymmetrically; drive trough a
Guanella-choke, but match the output of the choke

The Guanella balun, like all other transformer based baluns,
has the same upper and lower frequency limits: The inductance
sets the lower limit (more inductance -> lower frequency) and
the loss in the ferrite sets the upper limit (non-linear and thus
can be quite abrupt). Another issue here is symmetry of output
over frequency (c.f. [1]). I don't know how good the Guanella
baluns are in reality, but this is definitly something that should
be looked at.


Attila Kinali

[1] 
http://www.markimicrowave.com/blog/2013/07/why-buy-a-high-quality-baluntransformer-for-an-analog-to-digital-converter-adc/


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Re: [time-nuts] Heathkit clock available

[Alexander Pummer]

  before you buy AC line disciplined clock read that


 It hertz when you do that – power grid to stop regulating 60 Hz frequency

https://wattsupwiththat.com/2011/06/25/it-hertz-when-you-do-that-power-grid-to-stop-regulating-60-hz-frequency/

73
KJ6UHN
Alex

On 8/8/2016 2:29 PM, Nick Sayer via time-nuts wrote:

I just got an email announcing this:

https://shop.heathkit.com/shop/product/most-reliable-clock-tm-gc-1006-26

They bill it as a "most reliable" clock. From the description it appears to be 
an AC line disciplined clock with battery backup.

I only mention it here because of the periodic discussion of AC line discipline 
and because I suspect I'm not the only one who remembers the old Heathkit 
fondly.


Sent from my iPhone
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Re: [time-nuts] Looking to find an antenna for a TrueTime XL-DC

[Alexander Pummer]

Meinberg https://www.meinbergglobal.com/ makes complete down and up 
converter for GPS remote antennas


73
KJ6UHN
Alex

On 8/5/2016 3:11 PM, Rick Jones wrote:

On 08/04/2016 06:02 PM, Hal Murray wrote:


rick.jon...@hpe.com said:
HalM was kind enough to come over the other day with some antennae 
which  we

tried without success.


I was going to suggest taking the cover off and looking inside but it 
fell

off my to-do list.

GPS receivers are reasonably specialized.  I doubt it anybody makes one
targeted at the down-converter market.

Is there an up-converter in there feeding a normal receiver?  If so, 
it might

be possible/easy to bypass.

If it looks like a direct connection to a normal receiver, I'd guess 
it has
special firmware.  It might be possible to replace it with one with 
normal

firmware.


My peanut gallery level of knowledge means I wouldn't recognize a 
normal receiver if it reared up and, well, you know :)


I do though have some pictures of the relevant section of the machine 
with the cover off - two of the same shot at:


ftp://ftp.netperf.org/dc-xl

The antenna connection is the silver "square" on the left.  There are, 
as you can see, a number of jumpers everywhere.  The daughter card is 
connected at its "top left" in the picture where those "5s" of posts 
are.  There are some shiny gold (plated?) posts there underneath them, 
and a couple other vertical connections more towards the center.


That entire assembly can slide out of the chassis after removing four 
screws at the back.  I didn't try to remove the daughter card.


rick jones

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Re: [time-nuts] GPS antenna selection — lightning

[Alexander Pummer]

lightening protection:

http://www.ul.com/wp-content/uploads/2014/04/LightningProtectionAG.pdf

73
KJ6UHN
Alex

On 8/5/2016 1:51 PM, Attila Kinali wrote:

Hi Eric,

On Fri, 5 Aug 2016 10:37:28 -0400
Eric Scace  wrote:


A GPS antenna and its coax line that is installed next to a window is no
different from the same antenna/coax installed one meter outside the window…
or 10 meters away outside the window. All three installations are
effectively “outdoors” from an electromagnetic viewpoint, and all three need
effective surge protection from lightning-, cloud-, and precipitation-
induced voltage surges.

Please please please do NOT spread dangerous information like this!

While it is true, that an indoor antenna is suceptible to surges like
an outdoor antenna, it is not true that an outdoor antenna is equivalent
to an indoor antenna when it comes to lightning protection.

Because an outdoor antenna can be _directly_ hit by a lightning.

To protect the house and its inhabitants from the lightning strike,
an external antenna needs to be either lower than any lightning rod
and within its 45m ball or needs its own conductor and grounding
to discharge any lightning energy and thus preventing it from following
the antenna cable into the house.

Please be aware that the grounding of the antenna is not to protect
the equipment from surges, but to prevent conduction of the lightning
into the house that could cause electrocution and fires.

Attila Kinali



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Re: [time-nuts] The home time-lab

[Alexander Pummer]

you could bring the horse to the well.


On 7/24/2016 7:36 PM, Bill Hawkins wrote:

Years ago I knew exactly how Sola regulators worked. That has faded, but
what remains is that the regulation was done by varying the saturation
of the core. That's why there is a slot in the laminations. I find it
hard to believe that a partially saturated core can produce zero
harmonics.

In any event, the LC circuit does not filter anything. Possibly the
circuit counteracts the change in saturation as the line voltage
changes. I wouldn't expect it to effect the high frequency components of
spikes.

Any power supply that has a diode bridge and capacitor to create DC only
draws power from the line at the voltage peaks, when the diodes become
forward biased. I don't know of any choke input supplies, as were used
to reduce the peak current of vacuum tube rectifiers.

I know nothing about power factor correction for a bridge and capacitor,
whether or not it is followed by a switching regulator.

Make of it what you will.

Bill Hawkins


-Original Message-
From: Alex Pummer
Sent: Sunday, July 24, 2016 7:29 PM

That is interesting, since the Sola device has a to the line frequency
tuned tank circuit in it, thus the output should not have to many higher
harmonics and should look reasonable close to sinusoidal see here:
http://www.rdrelectronics.com/russ/jun16/vs2.PDF

73, KJ6UHN Alex


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Re: [time-nuts] HP5370 power supply measurements

[Alexander Pummer]

PABST KG in the Black Forest (Germany) made very quite high efficient 
fans, HP used to use these fans for awhile, but the company was sold and 
the quite fans disappeared, the new fans from the new owner   
http://www.ebmpapst.us/en/   are cheaper but not so good


73
KJ6UHN
 Alex

On 7/15/2016 1:25 PM, Tommy Phone wrote:

Some thirty years ago fans for automotive radiator cooling were designed with 7 
unevenly spaced blades to reduce the siren effect yet yield comparable air 
flow. Careful layout and blade sweep back along with an annular ring made it 
entirely feasible to have a statically and dynamically balanced fan as it came 
out of the mold. I always wondered why the folks who make these little fans 
can't figure out how to do that. Maybe getting comparable CFM from a much 
smaller fan violates some Reynolds number requirement for turbulence control.

 From Tom Holmes, N8ZM


On Jul 15, 2016, at 3:52 PM, William H. Fite  wrote:

That is, in fact, precisely how you do it.



On Friday, July 15, 2016, Orin Eman  wrote:

On Fri, Jul 15, 2016 at 10:55 AM, Poul-Henning Kamp >
wrote:



In message <
cany2ixq6onvridofgnfkebqjdkntp7t8kue7boupxjwlcux...@mail.gmail.com

>

, "William H. Fite" writes:

David Kirkby scripsit:

I often here of people replacing fans with quiter ones, but I suspect

that

all they really do is reduce the airflow.

Not necessarily, Dave. The Austrian company, Noctua, for one, makes
extremely quiet fans with excellent airflow.

... at zero pressure differential, which is easy to do (Think: ceiling
fan).



Right.

You have to look at the curves on the data sheet that shows air flow vs.
static pressure (and be careful about the static pressure scale).  I found
that a 'quiet' fan would often be flowing one tenth as much air as the
original fan at the static pressure at which the original fan was rated.

In a given instrument, you may get away with the quieter fan, but how would
you tell other than putting a thermometer inside and making a before/after
comparison?

Orin.
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Re: [time-nuts] The home time-lab

[Alexander Pummer]

if yo limit the Q you limit the effect also... by the way the Q is 
already limited by the ohmic resistance of your transformer coils.


73
KJ6UHN
Alex

On 7/8/2016 10:08 PM, David wrote:

And I will add a high voltage power resistor to limit the Q.

On Fri, 8 Jul 2016 22:12:53 -0400, you wrote:


Hi

If you try this, be very careful with the voltage at the junction of the L and 
the C.

Bob


On Jul 8, 2016, at 9:52 PM, David  wrote:

I wonder how well a pair of high voltage transformers wired back to
back with a 60 Hz series resonate LC circuit between them would work
for removing power line glitches.  They wouldn't do anything for
voltage regulation unlike a constant voltage transformer though.  Time
to break out a couple of plate transformers and try it I guess.

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

[Alexander Pummer]

KVG Neckarbischofshofen used to have a crystal in a glass envelope, 
which was made just for that purpose it was third overtone crystal ask 
Bernd if that is still available, of course you would need a low noise 
power amplifier to get that 1W


73
KJ6UHN
Alex



On 5/30/2016 4:06 AM, Dr. David Kirkby (Kirkby Microwave Ltd) 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] Rpair of an 8662 HP Generator

[Alexander Pummer]

the service manual is available here: 
http://elektrotanya.com/hp_8662a_sm.pdf/download.html,

special parts are here:  http://www.sphere.bc.ca/test/hpparts.html
possible repair: http://www.naptech.com/

73
KJ6UHN
Alex

On 4/15/2016 6:25 PM, KA2WEU--- via time-nuts wrote:

Thanks, I do not have a repair manual and I hate to abandon the signal
generator after man years of positive use... Ulrich
  
  
In a message dated 4/15/2016 9:14:21 P.M. Eastern Daylight Time,

paulsw...@gmail.com writes:

  
Ulrich

To  your first question I am unaware of anyone that repairs them. Though
there are  many places that might, typical cal and repair shops. I have a sick
8662 also  (age) and need to dig in. At least I know the board and the most
likely issue.  The yahoo user group has a lot of useful details.
Regards
Paul
WB8TSL









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Re: [time-nuts] Fast risetime pulse generator

[Alexander Pummer]

Hi Bill
check out the classical fast rise time pulse generator the mercury 
whetted relay, with a good lay-out you could get easily 50psec rise 
time, but rather use an SMA than BNC.

You could look for an old Tektronix pulse generator used that principle
73
KJ6UHN
Alex

On 4/12/2016 1:30 PM, BIll Ezell wrote:

(cross-posted to volt-nuts)
After paying only limited attention to this topic, I suddenly have a 
need for a pulse generator that has <150 ps risetime and a pulse width 
of at least 2 ns. 100mv amplitude or more is fine. I've looked at the 
classic Jim Williams avalanche generator, but I don't want to have to 
deal with the (relatively) high voltage source needed.


I've done microwave design using Gunn diodes, so I'm drawn to using a 
step-recovery diode. The topology seems very straightforward, and I 
can build it right onto a BNC connector, no PCB.


I'm thinking using an SMD835 diode, biased at ~1ma. The (sketchy) 
datasheet claims a T of 20 nsecs and a Tr of 85 ps, Cj of 0.4 to 0.8 pf.


Questions:

The obvious, is it reasonable?

Is the bias current reasonable? I'm assuming the bias current is 
actually dependent on the repetition rate, you need enough current to 
replenish the charge within one pulse cycle. I suppose I could compute 
it from the stated junction capacitance, but I'm not sure that's the 
only factor.


Will the stored charge actually give me the desired transition rate 
into 50 ohms? Hmm, again I should be able to compute this, but any 
other factors ignoring the non-diode ones like cap inductance?


How should I compute the coupling cap from the diode to the load? Use 
the impedance at the pulse rep rate? Seems reasonable. BTW, I don't 
care about droop in the  pulse, just the risetime. (measuring 
overshoot in an HF amp). Again, just want to verify that the obvious 
answer is the correct one. I clearly need to be very careful about the 
inductance.


Thanks, Bill



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Re: [time-nuts] Building a mains frequency monitor

[Alexander Pummer]

just look what is happening in one amplifier which happened to be a bit 
to slow for for the passing trough signal. The part of the spectrum -- 
which  can't make it -- although will not show up at the output, will 
not disappear, but --if the amplitude is large enough --  overdrive 
parts of the amplifier, causing recovery effects and delays. the delay 
will influence the propagation of the desired signals too. That is 
particularly important if the desired signals  position on the time 
range is important.
Also, by comparing the structure of a comparator and an amplifier it is 
very good visible, that a comparator, has much less stages which have 
all relative high bandwidth and lower gain, and the dominant pole -- 
which at the mentioned amplifier [LM358 ] is not much higher than 5 
[five] Hz, yes you could see it here: 
http://www.onsemi.com/pub_link/Collateral/LM358-D.PDF
It could happen that the signal coming out from a miss-used amplifier 
look very nice, but it is very likely, that it is not exactly correct, 
and there is a good reason, why the solid-state industry produce not 
just amplifiers but also compactors, which would need pre-filtering, but 
provides the correct output signal

73
KJ6UHN
Alex
who used to be corporate applications engineer at ON Semiconductor, 
Intersil Corporation and Elantec



On 4/12/2016 2:00 PM, Charles Steinmetz wrote:

Nick wrote:

At one point, I did try an LM393 instead of a 358. The result was 
that noise caused excessive false triggering. The 358, so far as I 
can tell, when acting as a comparator lacked sufficient bandwidth 
and/or speed to keep up with the noise.


My results also seemed to be on a par with the published results of 
other similar investigations (particularly those of tvb).


I'm on record as being in favor of pre-filtering to separate true grid 
phase artifacts from local noise, as much as practicable. However, it 
would be serendipitous indeed (more like miraculous, actually) if the 
slew-rate limit of an LM358 just happened to be exactly the right 
degree of filtering.  Close enough for a science-fair project, 
perhaps, but not a time-nuts-level solution.


Tom uses a Schmitt trigger input (which, as I pointed out yesterday, 
guarantees that the "non-zero-cross detector" [or, 
"zero-cross-by-proxy detector"] will have AM to PM conversion), and 
(last I knew) he does not filter the input (other than the incidental 
interaction of the input resistance of his pickup with the input 
capacitance of the gate).  A proper comparator with a 0v threshold and 
a few mV of hysteresis, preceded by carefully designed filtering, can 
generate a ZCD output with substantially lower cycle-to-cycle and 
second-to-second phase errors due to local noise that is a 
significantly more faithful representation of the actual grid phase 
and frequency.  If what we're interested in is measuring the grid 
phase and frequency, rather than the incidental local noise that has 
nothing to do with the grid phase and frequency, this is the clearly 
better approach, IMO.


Best regards,

Charles


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Re: [time-nuts] Advise on building a DIY GPSDO?

[Alexander Pummer]

and it is relative easy to make 10MHz from 8MHz with analog frequency 
manipulation, which generates less jitter

73

On 4/4/2016 4:27 PM, Attila Kinali wrote:

On Mon, 4 Apr 2016 17:56:29 -0400
Bob Camp  wrote:


The variable frequency output on the uBlox (and other) GPS receivers
has come up many times in the past.
If you dig into the archives you can find quite a bit of data on the
(lack of) performance of the high(er) frequency outputs from the various GPS
modules. They all depend on cycle add / drop at the frequency of their free
running TCXO. Regardless of the output frequency, that will put a *lot* of
jitter into the output.

That's why you should put the output frequency of the ublox modules
to an integer divisor of 24MHz. Ie 8MHz works but not 10MHz.

Attila Kinali



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Re: [time-nuts] Advise on building a DIY GPSDO?

[Alexander Pummer]

Building it cost you time and money, most likely much more than to buy,  
but you gain experience and you learn the limits of the different 
techniques, what you would not get to know other way

73
KJ6UHN
Alex

On 4/4/2016 1:15 PM, Dimitri.p wrote:
Regarding "as good a place to start as any",  ublox receivers will do 
10KHz all day long.
I didn't realize ublox receivers have dual output until after I built 
a couple of other GPSDOs, (well, maybe four)


As for a good  OCXO: other than the Morion MV89a, ($20-$50)  for 
anything else, figure about one or two hundred bucks depending on new 
vs used and "luck".


But as it's been said before it all depends on if you are building "to 
use" or "to play/learn/experiment/get your hands dirty"


Building does not save money or time and buying doen't give you an 
excuse to fire up the soldering iron.

Decisions...decisions...


Dimitri.p


At 12:00 PM 4/4/2016, Chris Caudle wrote:

On Mon, April 4, 2016 11:18 am, Tom Holmes wrote:
> The preceding questions always come up when a newbie
> comes up on the list wanting to build their own GPSDO.

It is good to make sure the person actually wants to build a GPSDO.
A few years back I was in a similar position, and my answer was I 
actually

needed a high accuracy reference to check frequency accuracy of some
clocks, and the recommendation was just get a Thunderbolt.  I didn't 
know

about surplus GPSDO's available so that was good advice for me, I didn't
actually >want< to build a GPSDO myself.  It would have been fun, but 
the

end goal was more important to me.

So I think really the first question should be do you want to build a
GPSDO, or do you want a high accuracy time and frequency source for its
own use?  Because if you want to own a GPSDO to use, building one 
yourself

is probably not the way to go.  Get a surplus unit, or save up a little
more and get a new Jackson Labs.
If you just like to build stuff and a GPSDO is the particular stuff you
want to build next, then go ahead and have fun.  Chris Albertson's 
arduino

based design is probably as good a place to start as any, it should be
cheap and I think the pieces are easier to find than that CPLD based
design that relies on having a GPS that can output 10kHz instead of just
PPS.

--
Chris Caudle



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Re: [time-nuts] Phase noise test set reference articles

[Alexander Pummer]

Hello Gerhard
look that: http://cp.literature.agilent.com/litweb/pdf/5989-8999EN.pdf
http://rfic.eecs.berkeley.edu/~niknejad/ee242/pdf/ee242_mixer_noise_design.pdf
and also STEPHEN MAAS has very good book on mixers...  Microwaves101 | 
Mixers

www.microwaves101.com/encyclopedias/mixers
Mixers. Check out our book recommendation page and order Stephen Maas' 
masterpiece on mixers!

73
KJ6UHN
Alex

On 3/29/2016 3:28 PM, Gerhard Hoffmann wrote:

Am 29.03.2016 um 16:53 schrieb Charles Steinmetz:


(10) Phase_detector_with_low_flicker_noise_BARNES_etal_NIST_2011: 
Describes a DIY double-balanced mixer phase detector using 
diode-connected 2N transistors.  [Note that only the flicker 
noise is improved -- the white noise floor is actually significantly 
higher than with DBMs using diodes.  NB: There are much better 
transistors than the 2N for this application.]
.. and they are NOT really used as diodes. They are used as switching 
transistors with most current flow C-E, saturation enforced.

That turns faster on than the diode exp-law.
Somewhere they also say that they use 50 Ohm load.

I really wonder where all that ring mixer noise is to come from. The 
diodes are just switches, the transformers
have close to no loss and behave properly in power dividers, and even 
when the diodes are resistors for a moment,

their noise is only half-thermal.

I find it easy to believe that high power mixers produce more noise. 
In that app note by Watkins-Johnson that everybody copies,
there it is clearly shown that they may use resistors to generate bias 
voltages.


If I use two 1:4 Wilkinsons, 4 low power ring mixers and put the 
outputs in series, will it also turn worse? I don't think so.


Are there anywhere musings about the equivalent noise resistance of a 
ring mixer IF output?
If it is really something like 500 Ohms, even a single AD797 may be 
excessively over-optimized

for voltage, and not current noise.

regards, Gerhard
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Re: [time-nuts] Phase noise test set reference articles

[Alexander Pummer]

and here is with very good literature: 
https://www.google.com/search?q=Haas+Mixer+noise=utf-8=utf-8#q=Maas+Mixer+noise


On 3/29/2016 3:28 PM, Gerhard Hoffmann wrote:

Am 29.03.2016 um 16:53 schrieb Charles Steinmetz:


(10) Phase_detector_with_low_flicker_noise_BARNES_etal_NIST_2011: 
Describes a DIY double-balanced mixer phase detector using 
diode-connected 2N transistors.  [Note that only the flicker 
noise is improved -- the white noise floor is actually significantly 
higher than with DBMs using diodes.  NB: There are much better 
transistors than the 2N for this application.]
.. and they are NOT really used as diodes. They are used as switching 
transistors with most current flow C-E, saturation enforced.

That turns faster on than the diode exp-law.
Somewhere they also say that they use 50 Ohm load.

I really wonder where all that ring mixer noise is to come from. The 
diodes are just switches, the transformers
have close to no loss and behave properly in power dividers, and even 
when the diodes are resistors for a moment,

their noise is only half-thermal.

I find it easy to believe that high power mixers produce more noise. 
In that app note by Watkins-Johnson that everybody copies,
there it is clearly shown that they may use resistors to generate bias 
voltages.


If I use two 1:4 Wilkinsons, 4 low power ring mixers and put the 
outputs in series, will it also turn worse? I don't think so.


Are there anywhere musings about the equivalent noise resistance of a 
ring mixer IF output?
If it is really something like 500 Ohms, even a single AD797 may be 
excessively over-optimized

for voltage, and not current noise.

regards, Gerhard
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Re: [time-nuts] Prescaler

[Alexander Pummer]

there is a very inexpensive one ADF4118 works up to 3GHz
which has a  programmable prescaler
http://www.analog.com/media/en/technical-documentation/data-sheets/ADF4116_4117_4118.pdf

more here: 
http://www.qsl.net/bg1ceo/Tech_topic/rf/7G_prescaler/prescaler.html

or here:  http://www.qsl.net/n9zia/pre/prescaler.pdf

73
KJ6UHN
Alex

On 3/27/2016 1:41 PM, Bob Camp wrote:

Hi

There are a *lot* of chips that will divide down from a couple of GHz. Once you 
have a chip, what do you do with it? There is more to a practical counter front 
end than just the divider. Getting it all to work requires a bit of time and a 
pretty good pc board.

This guy:

http://www.analog.com/en/products/rf-microwave/frequency-dividers-multipliers-detectors/frequency-dividers-prescalers-counters/hmc705.html

Will do a divide by 10 and go higher than your counter will. It’s a bit 
expensive … The eval board is cheaper than a single piece and it will give you 
a pretty good start.

This guy:

http://www.analog.com/en/products/rf-microwave/frequency-dividers-multipliers-detectors/frequency-dividers-prescalers-counters/hmc434.html

Will only divide by 8, it still goes higher than your counter. The eval board is a 
bit over $200. One piece of the Ic is < $12.

Bob



On Mar 27, 2016, at 3:45 PM, Bob Albert via time-nuts  
wrote:

Does anyone know of an inexpensive prescaler for a counter that goes beyond 2 
GHz?  I would actually like to find a kit but everything seems a bit pricy.  I 
currently have capability of 500 MHz and that will stretch to about 700 with 
care.  So a divide by 10 would be ideal.

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Re: [time-nuts] Spectrum Analyzer Specifications --> phase noise test set

[Alexander Pummer]

Use TNC, which is free of the problem and it fits into the same hole...
73
KJ6UHN
Alex

On 3/25/2016 3:46 PM, Bob Camp wrote:

Hi

The sensitivity of BNC connectors goes up quite a bit as they wear out. Both 
sides of
the connection are subject to wear. Replacing both sides is often the only 
solution when
they get noisy. That said, “screw down” connectors are a better way to go.

The “capacitive loading” termination of the mixer is something that a number of 
us
tried to reproduce when the paper came out. Even after fairly extensive 
conversations
with the authors, the effect seems be quite difficult to reproduce. It 
certainly is not a
“general solution” to the problem.

Bob



On Mar 25, 2016, at 5:55 PM, Bruce Griffiths  wrote:

As long as BNC connectors are avoided as their phase shift isnt that stable.. A 
small mechanical disturbance will change it significantly. Actually low noise 
PN measurement systems can be very sensitive to cable movement. Bolting modules 
to a metal baseplate helps a lot as does using intermodule connections 
comprising SMA(m)-SMA(m) barrels rather than cables.
There's also the question of mixer port termination.The nist paper by Walls and 
Stein indicates that capacitive termination of the IF port may be effective in 
reducing noise whilst maintaining a flat response fro dc to around 50KHz.Small 
value resistors in series with the RF and LO ports are then useful in reducing 
the VSWR.
Bruce


On Saturday, 26 March 2016 10:10 AM, Bob Camp  wrote:



Hi


On Mar 25, 2016, at 1:55 PM, jimlux  wrote:

On 3/25/16 5:07 AM, Bob Camp wrote:

Hi

The reverse isolation issue is indeed one of the weaknesses of this setup. For 
testing
OCXO’s isolation is not a big deal. A normal OCOX has very good output buffering
to give it the stability you are after. If you are running (maybe) a VCO with 
no buffering, that
assumption falls apart. The VCO will  / can injection lock through the mixer. 
In that
case you *do* need an amp to provide enough isolation to prevent the injection 
lock.



But if someone were building a little module for a cheap and cheerful noise 
analyzer, then the buffer amp would be a separate module.

That’s how I have always done it in the past. The need for the bufferer is rare 
enough that including it in the
basic analyzer module is not cost effective. The HP 3048 has the same basic 
issue (isolation) and they made
the same decision there.

Bob



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Re: [time-nuts] HP5370B & HP5345B Front-End IC Redesign Effort

[Alexander Pummer]

there are amplifiers with multiple GHz gain bandwidth product, 
[http://electronicdesign.com/analog/18-27-ghz-chip-set-operates-little-18-v] 
also the high speed  ECL line receivers have available gain 
[http://www.ti.com/lit/ds/symlink/sn65lvds4.pdf]

73
KJ6UHN
Alex

On 1/27/2016 2:22 PM, Bruce Griffiths wrote:

Achieving a bandwidth of 100MHz is easy. To get useful output at 500MHz
inductive peaking of the collector loads of the input stage will be required.
Correctly proportioned Bridged T-coils should work well.
Cascoding the input stage may also help.

Bruce

On Wednesday, January 27, 2016 08:38:15 PM Bruce Griffiths wrote:

Something like the attached schematic should suffice however an extra gain
stage would probably be necessary to achieve the 100mV sensitivity.NB Vcc =
15V, Vee = -15V. Bruce


 On Thursday, 28 January 2016 5:02 AM, paul swed 
wrote:


  Some great comments and like all of you I like my 5370s and 5345s. Real
buttons no mouse. Must be a throw back to the dark ages.
Always knew about the fan issue on the 5370 and have added fans to my main
operating unit.
But it had not occurred to me that the way the front panel is laid out
there may be little actual airflow across those chips. Thats quite a
thought.
So for those with working units that may be a completely seperate thread.
How hot do they get? Then some solution for that.
Essentially fix it before it dies.
Then there is the question I posed.
Skipping all of the details like adjustable slicing polarity and such.. What
is the minimum to get a signal into the counter as a way to return it to
some usable service and certainly verify the bad frontend. Lets call this a
poor but useful answer.
 From that point it returns to this discussion.
But a full new front panel. As Perry says most likely not.
I do have 2 X5345s that I am pretty sure I need to dive into the front end
on. My excuse other projects...
Regards
Paul
WB8TSL

On Wed, Jan 27, 2016 at 7:46 AM, Bob Camp  wrote:

Hi

Ok, well let’s put some dimensions on it.

Say that the new board for the counter costs $400 each. (and that’s
probably low). How many are people likely to buy?

If so how much would you pay for a working 5370?

Bob


On Jan 26, 2016, at 11:08 PM, Perry Sandeen via time-nuts <

time-nuts@febo.com> wrote:

Hi,
Wrote: Since the front end chips are mixed signal ASIC’s, it will take

more than a bit of time to replace them directly. Re-doing the entire
front
panel board is the most likely way to “fix”the problem. The question is -
why do that at all? Just do a PC instrument that does the same thing as
the
counter with way less effort…..


Well, I have two reasons not to.
First I have about $1800 invested in my 3 5370’s including  the new CPU

boards and blowing that off is not in my budget. I’ll kludge the living
daylights out of my units before blowing off my investment.


Second, I haven’t the slightest clue on how to do a PC instrument and I

have to many other projects to finish to learn something new.


Also there was much discussion about A and B cooling in the past and it

seems the only things some did to their units was the addition of fan(s)
on
the cooling fins.  I had an external fan on a B I was running and the
thing
still was too hot.


IMNSHO, I believe the front end chip failure is aggravated by the high

interior heat level.  I’m committed to a number of other projects so it
will be a while before I can work on mine.


I’ll either rip the whole PS out and put it on another chassis, try

better 3 terminal regulators instead of the installed pass transistors,
install switching regulator PS’s in place of the original PS, cut holes in
the top lid and install 10 or 12 computer fans. Or a combination of the
afore mentioned.


I don’t give a rat’s behind how it will look. I’m only interested in it

working properly.  I’ve spent 50 years in the electronics industry and I
will find a way to skin this cat. I’ve done this to other equipment
before.
And when done I’ll tell the list how I did it.


Regards,
Perrier
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Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?

[Alexander Pummer]

and there was also a frequency/phase detector from Analog Devices, which 
took care about that dead zone

73
KJ6UHN
Alex

On 1/10/2016 10:53 AM, Richard (Rick) Karlquist wrote:

Phase frequency detectors (starting with the legendary MC4044)
being made out of flip flops, had metastability and/or race
conditions.  Motorola showed a block diagram made of gates,
as if it were combinatorial logic, but because of the feedback,
it is actually a state machine, as described in the MC4044
data sheet.  It had a dead zone around zero phase that came
to light when Fairchild introduced the competing 11C44 PFD
using Eric Breeze's patent to fix the dead zone.  The
11C44 data sheet showed their dead zone, vs Brand M.
Even that improved chip still had a "funny" zone, it just
never went to zero gain.

Fast forward to today, we are now seeing PFD's made
with samplers.  They too have a bunch of issues with
phase noise floors.  None of them come close to a mixer.

In the 5071A, I used a mixer as a phase detector that
had some flip flops only used for acquisition, so they
were non players in terms of phase noise.  I still think
I would do that even if I had to do over 25 years later.

Rick Karlquist N6RK
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Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?

[Alexander Pummer]

"generate stable high -frequency signals  with d flip-flops as digital 
mixers ans all -IC low frequency phase -locked loop", by R.Treadway and 
L.J. Reed, page 78 Electronic design 1 January 1972

Resistot array denounces D flip-flop  mixer page 184 EDN 12 April 1990
digital frequency subtract or  EDN 1 April 1981
Kamil Kraus: Die Arbeitsweise eines einfachen Digitalmischer, Seite 72 
Elektronik Heft 24, 1980 a very good explanation of the function of the 
digital mixer-- in German
Design ideas; D flip-flop sutracs frequencies by Richard Kochis, 
Hewlett-PackardCo Ft. Collins ,CO, Gerald Flachs , New Mexico State 
University, Las Cruces, END 15 April, 10981 page 149
Robert a Pease National Semiconductor Corp : Four ICs subtract 
frequencies, EDN 1 April 1981
"Digitalis keverofokozat tervezese",  Zombay Frerenc, Radiotechnika, 
Seite 244 # 5 1996,  a complete design of the digital mixer with 
detailed theory and example in three consecutive issue of the magazine 
Radiotechnika -- in Hungarian.
By using that literature I designed many frequency synthesizers 
containing D flip-flops as a digital mixer


73
KJ6 UHN
Alex
[alias Dr.Dipl.Ing. Alexander Pummer, PCS Consultants]
US patents:  many if you are interested I will send you a list


On 1/10/2016 10:56 AM, Attila Kinali wrote:

On Sun, 10 Jan 2016 14:30:41 +0100
Magnus Danielson <mag...@rubidium.dyndns.org> wrote:


SR-flipflop? Are you refering to the JK-FF phase detector or the PFD?

A straight SR-flipflop. I would have written JK-FF or PFD if I meant it.
Also, as I mentioned the PFD directly after, you could have concluded
that was not what I intended.

A SR-flip-flop with no illegal input states is easy to build from a 74HC00.

The illegal input states were my concern, indeed. And a quick google
didn't show up anything to disperse thesenot until I started reading
the 4046 datasheet in detail.

But there is one thing about the arangement of the SR FF in the 4046[1]
that bothers me:
Although S = R = 1 is valid, it does lead to the output oscillating
between 0 and 1.


Attila Kinali


[1] Ti CD74HC4046A Datasheet
http://www.ti.com/lit/ds/symlink/cd54hc4046a.pdf



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Re: [time-nuts] PPS phase between two GPS units.

[Alexander Pummer]

swap the two receivers and see which one is leading, if leading is 
changing the delay difference is with the antenna signal distribution

73
KJ6UHN
Alex
On 12/21/2015 8:03 PM, paul swed wrote:

I think you are doing the right test to see if the splitter delay is the
issue 21 ns is mighty small and a real possibility.
Regards
Paul
WB8TSL

On Mon, Dec 21, 2015 at 8:24 PM,  wrote:


Hi All,

So I've been playing with some timing hardware here, and have noticed
something rather curious. I have two otherwise identical Lea-6T GPS
modules, configured exactly the same. These units are tied to the same
antenna, with a splitter with the same length cables running to each unit.
They were given the same survey coordinates. Initially there was not any
appreciable difference between the PPS outputs. The outputs were on average
within about one nS of each other. However after a day or two they started
to display a difference of about 21nS between the PPS outputs. This is also
evident in the GPSDO output, as the phase of the 10Mhz is also skewed by
21nS or so.

A few days ago I started a 48 hour survey. The came up virtually identical
coordinates at the end of that survey. After the survey the phase is still
21nS different.

At this point, my only thought is the GPS splitter. It's DC coupled to one
unit, and AC coupled to the other. It is possible there are some delays on
one output vs. the other due to the blocking caps and bypass inductor in
the splitter. I've tried swapping the GPSDO units on the splitter, so we'll
see what happens there.
Can anyone offer any insight as to why the two units may have a different
PPS output timing? It's not really a problem, more of a curiosity and
mildly academic exercise.
Thanks,
Dan







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Re: [time-nuts] Mechanical clock sound pickup circuit

[Alexander Pummer]

Once upon the time there was a "Vibrograph", see nice pictures here: 
https://www.google.com/search?q=vibrograph=isch=u=univ=X=0ahUKEwigtcmSn9fJAhUW8GMKHVNyAMcQsAQIHA=1760=888 
,which picked up the sound of watches, clocks, and the watch maker was 
able to set the watch very accurately, these machines did not used any 
fancy DSP despite that they worked very well, I myself used one some 55 
years ego in Switzerland,.
to get a reliable digital signal from a noisy analog signal is the most 
reliable way to use an analog PLL with a linear multiplier type phase 
detector  [ at least one input of the phase detector must be linear e.g. 
a transitional gate [cd4016 and it's derivatives ], the noise could be 
filtered out with a low pass filter or integrator, the price of the 
method is that it also eliminates the phase-noise of the the input signal, .

That was the method which was used by the Vibrograph.
73
LJ6UHN
Alex

On 12/12/2015 7:15 AM, Dave Martindale wrote:

Someone is in the process of writing open-source watch timing software.
You may want to look into it.

It was announced here:
http://forums.watchuseek.com/f6/open-source-timing-software-2542874-post21977314.html#poststop

It contains these links:
First the goodies. Here are Windows binaries
http://ciovil.li/tg.zip
and here is the full source code
https://github.com/vacaboja/tg

Apparently this software is better at dealing with noisy signals from
microphones than Biburo.  Since it's open source, you can see what it's
doing internally.  It expects an analog input, and does its own filtering
to find the interesting edges within the sound of each tick.

The precision with which you can time events is likely to be limited by the
frequency response of your sensor and the amplifier.  If that's limited to
20 kHz, a standard PC sound card is adequate.  For up to 80 kHz or so, you
can buy a relatively inexpensive USB "audio interface" that digitizes at
192 kHz (typically 24 bit resolution).  At somewhat higher cost, you can
get professional audio interfaces that accept an external clock source.

- Dave


On Fri, Dec 11, 2015 at 1:44 PM, Andrea Baldoni 
wrote:


Hello!

I decided to do some experiments with mechanical clocks, so I worked a
little
on picking up escapement ticking sound, with the idea of processing it and
obtaining a "clean" digital pulse to feed a counter.

So far, I have not yet been able to find the best way to obtain a digital
pulse,
but I have already built the preamp for the piezoelectrick pickup, that
I used to feed the mic input of a PC sound card for spectrum analysis.

The timing could eventually be done in software because the whole idea of
measuring watches by picking up their noise almost surely doesn't allow
high
resolution anyway, but I will plan to try hardware solutions as well in the
future. I hope to be able to measure the jitter of the clock, but it will
be
very hard.

In the meantime, with the free software Biburo you can download here

http://tokeiyade.michikusa.jp

you can regulate your wrist watch.

Best regards,
Andrea Baldoni

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Re: [time-nuts] GPSDO and oscillator steering - EFC vs DDS schemes?

[Alexander Pummer]

Bar Giora Goldberg wrote a book on DDS Digital Frequency Synthesis 
Demystified 
see 
here: 
http://www.amazon.com/Frequency-Synthesis-Demystified-Bar-Giora-Goldberg/dp/1878707477
[· In-depth coverage of modern digital implementations of frequency 
synthesis architectures

· Numerous design examples drawn from actual engineering projects
· The accompanying CD includes digital frequency synthesis design tools 
and an electronic version of the book]
Hi was the chef technologist of  Sciteq, that company made the first 
usable DDS devices.

73
KJ6UHN
Alex


On 12/8/2015 4:00 PM, Attila Kinali wrote:

On Tue, 8 Dec 2015 10:09:44 -0800
Jim Lux  wrote:


What puzzled me is, why this has not been used more often to correct
the frequency of OCXOs instead of using some DAC-to-EFC scheme?

Heritage... if you have a design that works, and there's a lot of them
in the field, and the idiosyncracies are well known and understood, then
one tends to stay with the old design.

That might be an explanation.


DDS are "brand new", at least in terms of generating low spurs, etc.
The idiosyncracies are not as well understood.

Well, Rick's paper is already 20 years old. There has been lots of
discussion of DDS in the radio community and I think that community
has a lot of knowledge of the idiosyncracies of DDS. I'm not sure
how it works for the  time and frequency control community, though.


I think also the power consumption might be an issue.  Most good DDS
burn a lot of power, compared to a DAC.

Compared to the 1-5W steady state of an OCXO?
But yes, the circuit would probably need something in the range of 2-3W.
  

There's also systems that depend on smooth sweeps without steps (yes,
one can design a DDS with a digital ramp generator driving the increment
in a phase accumulator to get arbitrarily smooth sweeps, but the "off
the shelf" parts don't do this)

I might be naive, but I would have used an small FPGA with EEPROM cells
(like the Lattice ICE or the Altera MAX) and build an DDS by hand that
is tailored for exactly that purpose (to get minimal spurs), add an
10bit DAC, combine everything with an 60-100MHz VCXO that is PLL-locked to
the 10MHz input. Well, actually the VCXO might not even be necessary,
if the FPGA internal PLL is not too noisy, there is some heavy "damping"
of the noise through the divider stages anyways.



I don't think parts cost is a big driver.


Unless you are a hobbyist.


Attila Kinali



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Re: [time-nuts] GPS down converter question

[Alexander Pummer]

actually the 34MHz filter [Meinberg scheme ]could be made at home, by 
using old 10,7MHz FM-IF filters magnetic material, once upon the time I 
made some 27MHz filters that way, for 70MHz is bit risky, since there is 
no salvageable out there,
perhaps by using some "binocular" cores made for 100MHz from old FM 
radios input or some Amidon parts with trim-cap tuning could work

73
KJ6UHN
Alex
  On 12/2/2015 2:42 PM, Bob Camp wrote:

Hi

Indeed (as I suspected) that 75 MHz filter runs up the total parts cost quite a 
bit.
First thing I’d do is take a look at the board this connects to. Does it 
already have
a narrowband filter (at 75 MHz) on it?

Bob


On Dec 2, 2015, at 10:36 AM, paul swed  wrote:

To Bobs comments your right. That 75 MHz may not be needed because of the
1575 input filter. That would save $29.
By the way I was shocked to see for all of $3 complete 1575 filter and LNA
chips. The only nasty challenge is the chips are extremely small. The cost
is low enough I can purchase several in case I screw it up. Its clearly
going to be at my maximum soldering skills.
Regards
Paul
WB8TSL

On Wed, Dec 2, 2015 at 10:32 AM, paul swed  wrote:


My bad mixing threads here the 1575 filter is in mouser and digikey has
them.
The 75 MHz is straight from mini-circuits.
Regards
Paul
WB8TSL

On Wed, Dec 2, 2015 at 10:31 AM, paul swed  wrote:


Sorry mouser electroncs.

On Wed, Dec 2, 2015 at 8:10 AM, Herbert Poetzl 
wrote:


On Tue, Dec 01, 2015 at 08:33:05PM -0500, paul swed wrote:

Digikey was a strike out with 1 filter for 86 cents but
order was 1000 units.

Sorry, but could you point me to the filter in question
please, I couldn't find anything on digikey, but probably
I was searching for the wrong keywords.

Thanks in advance,
Herbert


Mouser however has a wide assortment very reasonable and
by the single units.
Hardest thing will be soldering them.
Regards
Paul
WB8TSL


On Tue, Dec 1, 2015 at 8:29 PM, paul swed  wrote:


Hello to the group have indeed done the 1575 down to 35.42 to 75.42

and

upconverter trick.
Thats what I used for 2-3 years now and thought it was time to move

beyond

that approach. Especially due to the earlier conversation on old

receivers

and that they should still work just fine if you do not care about

the date.

I actually have 2 versions of the 35 to 75 converter. One using an

odetics

down converter and another using a starlink gps receiver. Both have

35.42

MHz IFs. Old stuff you can get a soldering iron into.

No intention to put this on the tower and mini-circuits makes a good

BPF

for the 75 MHz IF. Since I will believe the actual antenna has a 1571
filter in it I was thinking of skipping it down in the shack.

Will see what digikey and mouser has in the way of filters and if
inexpensive may buy one. I keep thinking I may actually have one

also.

Thanks again everyone.
Paul
WB8TSL

On Tue, Dec 1, 2015 at 7:53 PM, Alex Pummer 

wrote:

for 70MHz it does not hurt to match the cable to the filter at the
antenna unit [down converter]  end  and also match the filter at the
receiver upconverter end, the cable will pick up enough noise to

overdrive

the 70 something receiver's input  [ the "outside" field will drive

a

current in the cable's shield, but not in the center conductor, that
current causes noise voltage between the two end of the cable's

shield

which will end up at the input of the receiver, therefore it need

to be

filtered out before it hits the mixer..also the down

converter's LO's

reference is sensitive to the noise which the cable will pick up [

will

cause phase noise ], therefore it needs to be filtered .
That down up converter system is an interesting project but it is

not

that simple as it looks
73
KJ6UHN
Alex


  On 12/1/2015 2:57 PM, Bob Camp wrote:


Hi

Here’s sort of a backwards look at it:

Do you *need* an IF filter in the downconverter? By that I’m asking
about a
filter better than a simple LC tank. Did they put the filter in the
downconverter
or in the main box? I would think that putting a fancy filter up

by the

antenna
would have been a less likely thing to do than putting it down in

the

main box.

Bob


On Dec 1, 2015, at 9:48 AM, paul swed  wrote:

Thanks everyone. The Meinberg is nice and maybe available from

Ebay by

Alex's link. But its 35.42 much as the Odetics down converter. I

am

looking
to create a 75.42 Mhz IF.
Mini-circuits makes just the right parts. But had several IF

bandwidths

available.
So will go with the 2 or so MHz filter as suggested.

I have the typical GPS better quality high gain antenna 1/2"

Heliax

feed to
a low noise gain block that makes up for the loss of a 8 X

splitter.

I may add a 1575 filter ahead of the 10 db amplifier and then hit

the

mixer. I think I have a filter. I actually question that I need

the

filter
or 10 db amp. May build 

Re: [time-nuts] Low noise quartz crystal oscillator by Bruce Griffiths

[Alexander Pummer]

Hi Rick,
any info on how Wenzel makes that low noise oscillators?
73
KJ6UHN
Alex

On 10/28/2015 3:04 PM, Richard (Rick) Karlquist wrote:

Do you have a specific URL for "hacking oscillators"?  I can't
find it on Rubiola's web site.

Rick

On 10/28/2015 1:32 PM, Gerhard Hoffmann wrote:

Am 28.10.2015 um 19:22 schrieb KA2WEU--- via time-nuts:
This oscillator seems to have been more a frequency standard then a 
noise

standard. Today's 10 MHz oscillators are different/better, such a
crystal is
no  longer available/made.

Yes. Rubiola gives it the credit of being able to be mass-produced, and
it _was_
one successful product. There is a section in "hacking oscillators" 
on it;

my copy of the book is 200 miles away right now.

regards,

Gerhard, DK4XP


(see www.rubiola.org)
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Re: [time-nuts] Digital Phasae Lock Loops

[Alexander Pummer]

Hi Steve,
I will tell you a big secret; a digital PLL is not a low phase noise 
system and a very good introduction to PLLs and the digital PLL could be 
found in Roland Bests:



 Phase Locked Loops 6/e: Design, Simulation, and Applications

73
KJ6UHN
Alex


On 10/16/2015 7:45 AM, Martyn Smith wrote:

Hello,

I want to design a digital phase lock loop.

I intend to lock a 10 MHz ultra low noise oscillator that we make to an 
external frequency standard.

I need a digital PLL as I’m trying to get a loop bandwidth < 0.1 Hz.

Has anyone had any experience of Digital PLL’s or can point me to any documents 
published?

Regards

Steve
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Re: [time-nuts] Digital Phasae Lock Loops

[Alexander Pummer]

actually my old friend Dr. Floyd Gardner -- who is the pope of the phase 
locked loops -- told me some thirty years ego , that the Best book os a 
very good introduction

73
Alex

On 10/16/2015 1:42 PM, Dave Daniel wrote:
Roland Best's text is the best (no pun intended) one I have seen on 
PLLs. I didn't know it was up to a sixth edition.


On 10/16/2015 11:18 AM, Alexander Pummer wrote:

Hi Steve,
I will tell you a big secret; a digital PLL is not a low phase noise 
system and a very good introduction to PLLs and the digital PLL could 
be found in Roland Bests:



 Phase Locked Loops 6/e: Design, Simulation, and Applications

73
KJ6UHN
Alex


On 10/16/2015 7:45 AM, Martyn Smith wrote:

Hello,

I want to design a digital phase lock loop.

I intend to lock a 10 MHz ultra low noise oscillator that we make to 
an external frequency standard.


I need a digital PLL as I’m trying to get a loop bandwidth < 0.1 Hz.

Has anyone had any experience of Digital PLL’s or can point me to 
any documents published?


Regards

Steve
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Re: [time-nuts] Digital Phasae Lock Loops

[Alexander Pummer]

yes as I wrote Dr. Gardner is the pope of the phase locked loops, his 
book is a heavy weight, not for beginner

73
Alex
10/16/2015 4:16 PM, Dave Daniel wrote:

Wasn't Dr. Gardner the author of "the other" PLL book? Or am I confusing
his name with another Gardner?

DaveD

On 10/16/2015 4:33 PM, Alexander Pummer wrote:
actually my old friend Dr. Floyd Gardner -- 
who is the pope of the

phase locked loops -- told me some thirty years ego , that the Best
book os a very good introduction
73
Alex

On 10/16/2015 1:42 PM, Dave Daniel wrote:
Roland Best's text is the best (no pun 
intended) one I have seen on

PLLs. I didn't know it was up to a sixth edition.

On 10/16/2015 11:18 AM, Alexander Pummer wrote:
Hi Steve,
I will tell you a big secret; a digital PLL is not a low phase noise
system and a very good introduction to PLLs and the digital PLL
could be found in Roland Bests:


Phase Locked Loops 6/e: Design, Simulation, and Applications

73
KJ6UHN
Alex


On 10/16/2015 7:45 AM, Martyn Smith wrote:
Hello,

I want to design a digital phase lock loop.

I intend to lock a 10 MHz ultra low noise oscillator that we make
to an external frequency standard.

I need a digital PLL as I’m trying to get a loop bandwidth  
0.1 Hz.


Has anyone had any experience of Digital PLL’s or can point me to
any documents published?

Regards

Steve
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Re: [time-nuts] wtd: WWVB info

[Alexander Pummer]

it looks like somebody already made a decoder for a wwvb like  
transmission, see here:



 Performance Analysis and Receiver Architectures of DCF77
 Radio-Controlled Clocks

 *
   Daniel Engeler
   Daniel Engeler
   researcher/75928367_Daniel_Engeler

Zuhlke Engineering AG, Schlieren, Switzerland.
IEEE transactions on ultrasonics, ferroelectrics, and frequency control 
journal/1525-8955_IEEE_transactions_on_ultrasonics_ferroelectrics_and_frequency_control 
(Impact Factor: 1.5). 05/2012; 59(5):869-84. DOI: 10.1109/TUFFC.2012.2272

Source: PubMed http://www.ncbi.nlm.nih.gov/pubmed/22622972

*ABSTRACT* DCF77 is a long-wave radio transmitter located in Germany. 
Atomic clocks generate a 77.5-kHz carrier which is amplitude- and 
phase-modulated to broadcast the official time. The signal is used by 
industrial and consumer radio-controlled clocks. DCF77 faces competition 
from the Global Positioning System (GPS) which provides higher accuracy 
time. Still, DCF77 and other long-wave time services worldwide remain 
popular because they allow indoor reception at lower cost, lower power, 
and sufficient accuracy. Indoor long-wave reception is challenged by 
signal attenuation and electromagnetic interference from an increasing 
number of devices, particularly switched-mode power supplies. This paper 
introduces new receiver architectures and compares them with existing 
detectors and time decoders. Simulations and analytical calculations 
characterize the performance in terms of bit error rate and decoding 
probability, depending on input noise and narrow-band interference. The 
most promising detector with maximum-likelihood time decoder displays 
the time in less than 60 s after power-up and at a noise level of 
E(b)/N(0) = 2.7 dB, an improvement of 20 dB over previous receivers. A 
field-programmable gate array-based demonstration receiver built for the 
purposes of this paper confirms the capabilities of these new 
algorithms. The findings of this paper enable future high-performance 
DCF77 receivers and further study of indoor long-wave reception.


The DCF77 has very similar modulation scheme as the new wwvb, therefore 
the methode used to decode the DCF77 could be used --perhaps with some 
modifications -- to decode the phase modulation of the wwvb also

74
KJ6UHN
Alex

On 8/9/2015 7:57 PM, John Allen wrote:

Hi Jim -

You wrote:
At some point, multiproject wafers (like MOSIS) might become a hobby
product.  So far, it's in the several kilobuck minimum purchase, and,
as well, the tools aren't easy to come by. Or, more properly, good
design tools are expensive, tedious design tools are free.. you CAN
layout an IC for MOSIS with a ruler and and a quadrille pad.. get your
copy of Carver and Mead and have at it)

I assume that you mean Carver Mead and Lynn Conway, Introduction to VLSI System 
Design 1978.

I am enjoying this thread!

Regards, John Allen K1AE

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Jim Lux
Sent: Sunday, August 09, 2015 9:12 PM
To: time-nuts@febo.com
Subject: Re: [time-nuts] wtd: WWVB info

On 8/9/15 4:33 PM, Bob Camp wrote:

Hi

If you never have tried to keep an IC in production, there are some basic things
that may not be very obvious:

snip

There's always Rochester Electronics.. leaders in the trailing edge
(no kidding, that's their slogan)..

They buy old fabs, masks, etc, and keep producing small runs of older
parts.  For a price.

At some point, multiproject wafers (like MOSIS) might become a hobby
product.  So far, it's in the several kilobuck minimum purchase, and,
as well, the tools aren't easy to come by. Or, more properly, good
design tools are expensive, tedious design tools are free.. you CAN
layout an IC for MOSIS with a ruler and and a quadrille pad.. get your
copy of Carver and Mead and have at it)

For digital stuff, small boards with FPGAs or microcontrollers on them
are probably the sweet spot for small runs.

The same is not true for analog.



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Re: [time-nuts] wtd: WWVB info...

[Alexander Pummer]

a software demodulator for the DCF77 was published last year, the DCF77 
has similar modulation structure as the new wwvb it was developed at a 
Swiss company

73
KJ6UHN
Alex

On 8/6/2015 3:11 PM, Donald wrote:

I have found this old posting from 2014:
https://www.febo.com/pipermail/time-nuts/2014-August/086043.html

Ivan Cousins states:
A WWVB receiver can now be done on an Arduino microprocessor with a 
little help from an antenna. 


Googleing has not found such an article or project.

Has this ever happened ?

Is Ivan still around and can he shed light on this topic.

Thanks
Don

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Re: [time-nuts] 60Hz line data

[Alexander Pummer]

but for a very long time we get --or better to say got in the past -- 
the correct number of periods of the line frequency, I have two clocks 
side by side -- one driven by the power line the other is  an atomic  
clock from Westclox guided by WWVB and the seldom disagree  about the 
time

73
KJ6UHN
Alex

On 8/4/2015 5:17 PM, Hal Murray wrote:

b...@iaxs.net said:

Frankly, I'm puzzled by the graphs that relate to the time offset. All
that's available to the observer is the line frequency. Relative time may be
inferred with a cycle counter. How is that counter set to UTC? How can you
tell the difference between time error from some reference point, and cycles
gained or lost in the counting equipment - due to noise and/or computer
interrupt servicing routines?

The counter isn't set to UTC.  The zero point on the vertical offset is
arbitrary.  All you can measure is the drift relative to some arbitrary
point.  I used the start of the data as zero.  That's the same as setting
your wall clock to UTC when you first took it out of the box and plugged it
in.

If you look in the archives, there is a time-lapse movie make with one frame
each minute when the second hand started straight up.


I'm pretty sure my setup isn't gaining or losing many cycles.  Actually, I'm
pretty sure it is picking up an occasional extra cycle because I see them.
10 seconds at 60 Hz is 600 cycles.  If you get an extra count, the frequency
will be off by 0.1 Hz.  Since the normal range is much less than that, a
sample with an extra cycle stands out.  They are infrequent enough that I
look at each one by hand and make a graph like this:
   http://www.megapathdsl.net/~hmurray/time-nuts/60Hz/60Hz-2012-Jan-26-a-pick.p
ng

I'm using a human filter.  I haven't tried to automate it.






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Re: [time-nuts] HP10811 dual oven

[Alexander Pummer]

Hi Dan,
I would be interested on that document too
Thank you in advance
73
KJ6UHN
Alex

On 8/3/2015 12:40 PM, Dan Kemppainen wrote:

Hi,

If you search the internet, you should come across a design by Warren 
S. It's basically the same type of oven controller that is used in the 
internal oven for that oscillator.


I did a surface mount version of his design a while back. I've been 
running it for quite a while now. IMO it is helping to reduce the 
thermal drift of the oscillator.


Bob has pointed out in the past that the outer oven was not intended 
to be active all of the time. This is probably true. That said it 
seems to help in my setup.


If you are unable to find the documentation, please let me know. I can 
try to dig it up when I get home.


Dan




On 8/3/2015 12:00 PM, time-nuts-requ...@febo.com wrote:


Hi

The “external” heater on the Z3801 OCXO is only needed if you are 
regularly running below -20C in your environment. Other than
the alarm signal, there is no harm in letting it simply shut off 
forever.


Bob


On Aug 2, 2015, at 8:56 AM,tim...@timeok.it  wrote:


Hi,
I have seen, but I do not remember where, someone have rebuilt the 
external oven controller to complete a stand alone OCXO removed from 
an HPZ3801A.

Can you hep me to find the document?

Luciano
timeok

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Re: [time-nuts] Square to sine wave symmetrical conversion (part 2)

[Alexander Pummer]

it is relative easy to make a perfect 50% square wave from almost any 
input wave form


U1 could be any-- fast enough  for the desired frequency--comparator or 
a transistor pair similar to Charles Wenzel's  circuit, R1 C1 is a long 
time integrator,[ RxC  1/f of the incoming frequency] the voltage at 
A is proportional with the duty cycle, U 2 is some high gain low 
noise, low input offset voltage high input impedance amplifier, the 
duty-cycle is set by R4/R5,  fine tuning with R6, C2v removes the noise 
Vr is well stabilized reference voltage,
To set up the circuit the output should be connected -- with DC 
decoupling -- to a spectrum analyzer's input for watching the second 
harmonic [a perfect 50% duty cycle square wave lacks of even harmonics 
..] of the input frequency, which has to be adjusted to minimum with R6, 
using the same stile resistors for ±0,1%, R4 and R5, with value 100 
times of R6 a very good temperature stability could be achieved. for 
better short time stability R2 's top could bealso connected to Vr,
If the drive capability of U1 is not enough for the load non-inverting 
buffers could be inserted to U1's output, of course that circuit wil 
contribute some phase noise/ jitter too.

73
KJ6UHN
Alex


On 7/25/2015 1:34 AM, tim...@timeok.it wrote:



bypassing the inverter you will improve phase noise. Yuo will probably
need a sine buffer at 10MHz to drive 50 ohms.

This separator con be the solution:  
http://www.timeok.it/files/hp5065AoptH10v200.pdf
high input impedance, output 50Ohm, high power handling and low additive phase 
noise.

But before measure using an oscilloscope the output of the GPS OCXO directly on 
the output pin to verify if there is a sine-wave or square

Luciano
timeok
Message sent via Atmail Open - http://atmail.org/
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Re: [time-nuts] LORAN on the air 89700 been a good day so far

[Alexander Pummer]

Hi Bill,
it is very dependent which is closer to the receiver
here in the Bay Area sometimes you can't hear local AM stations either.
73
Alex KJ6UHN

On 7/21/2015 3:15 PM, billriches wrote:

Hi Alex,

100 Khz is not protected however the interference from SMPS is annoying but
will not bother loran transmissions as it is much stronger than that
interference.

73,

Bill, WA2DVU

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Alex Pummer
Sent: Tuesday, July 21, 2015 11:58 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] LORAN on the air 89700 been a good day so far



Hi Bill ,
is the Loran frequency 100kHz protected? because there are may switching
mode power supplies which generate lots of Loran replacementsthe same is
with wwvb 's 60kHz
73
Alex KJ6UHN

On 7/21/2015 4:26 AM, billriches wrote:

Alex - are you referring to the test of eloran in progress from Wildwood

NJ?

That of course is on 100 Khz.  There is no Loran in California at this

time.

73,

Bill, WA2DVU
Cape May

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Alex
Pummer
Sent: Monday, July 20, 2015 9:03 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] LORAN on the air 89700 been a good day so far

Hi Paul
where could I find the frequency of our Loran [the Californian Loran
] I have an old HP3586 radio receiver
73
Alex

llow the instructions there.


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Re: [time-nuts] Electronically Disciplined Mechanical

[Alexander Pummer]

Hi Bert
at the Neu Tecknicumbuchs, /Buchs/, Switzerland somebody made a diplom 
work a quite-few years ego very similar clock, the pendulum was 
synchronized to the 75kHz accurate time transmitter, you may could find 
out more about it at  the Neu Tecknicumbuchs, /Buchs/, Switzerland

73
KJ6UHN
Alex

On 6/9/2015 7:26 AM, Bert, VE2ZAZ wrote:

Hi Tom,
Thanks a lot for your feedback and for having been an inspiration for this 
project.

With a temperature-stabilized setup, it is now concievable to run the system at 
a constant impulse duration. This would not have been possible without 
temperature control, as the pendulum arm length varied too much to maintain an 
oscillation using a constant impulse width. I tried this overnight at a couple 
of occasions with an aluminium arm, only to find the pendulum dead in the 
morning...  :-o

So in order to achieve this, I will add a serial command to keep the last 
impulse duration. That command would be sent once the system is fully 
stabilized.
Thanks,
Bert, VE2ZAZ

Message: 8

Date: Mon, 8 Jun 2015 14:46:50 -0700
From: Tom Van Baak t...@leapsecond.com
To: Discussion of precise time and frequency measurement
 time-nuts@febo.com
Subject: Re: [time-nuts] Electronically Disciplined Mechanical
 Pendulum
Message-ID: ED4D31631FC440A19A71631386F46143@pc52
Content-Type: text/plain;charset=utf-8

Hi Bert,

Thanks for posting that project. What a wonderful combination of electronic and 
mechanical timing, of design and measurement, of hardware and software, of PICs 
and Python.

One side experiment that would be interesting is to collect a couple of days of 
data using a fixed drive and then compare that with the same number of days 
using your adaptive FLL drive. The resulting phase or rate or ADEV plots would 
be amazing.

/tvb

- Original Message -
From: Bert, VE2ZAZ ve2...@yahoo.ca
To: time-nuts@febo.com
Sent: Monday, June 08, 2015 10:11 AM
Subject: [time-nuts] Electronically Disciplined Mechanical Pendulum



Greetings,


I just want to let those who are curious about disciplining a mechanical 
pendulum that I have pretty much wrapped up playing with a 1m-long pendulum, 
which I control with PIC micro firmware and try to mainain at a constant 
temperature. Accuracy for 20-second averaging is typically better than 1 ppm. I 
have documented my work here:

On my website ( http://ve2zaz.net/Pendulum_Ctl/Pendulum_Ctl.htm ),
On Youtube ( https://www.youtube.com/watch?v=7NdGX4A8W88 )

Thanks,

Bert, VE2ZAZ




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Re: [time-nuts] lawnmower robots may be the end of VLF timekeeping

[Alexander Pummer]

Bob Widlar -- yes the designer of the 741 -- of National Semiconductor 
had a better idea, he bought a few sheep

73
KJ6UHN Alex

On 5/9/2015 2:02 PM, Mark Sims wrote:

iRobot (the Roomba vacuum cleaner people) have applied for an exemption to 
allow them to send beacon signals in a 6-7 GHz band to fence in their new 
lawnmower.  The band they want to operate in is apparently for indoor only low 
power applications.

The easy solution is to just buy some goats...  the emit very little in the way 
of EMI...  but do emit other,  u,  signals.

--
Clearly, you need a better nav system for the robot based on precision
time of flight measurements from a network of transmitters around the
property linked to your hydrogen maser. 
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Re: [time-nuts] Tektronix Sample Heads

[Alexander Pummer]

and  be very careful, it does not tolerate more than ±2  volts input! it 
was originally designed for the CSA 803A and requires a relative 
complicated control system, it has a 15  to 18 picoseconds rise time, 50 
ohms input, and at least 30dB return loss at 18GHz. If both inputs are 
used they are differential.

73
KJ6UHN Alex

 On 4/24/2015 12:51 PM, ed breya wrote:
Yes, I think those were from the era when service info became sparse - 
treated as modules or black boxes -  unlike the products from the good 
old days, which had much more info available.  I believe the SD26 is 
to fit in the Tek 11801B or other 11000 series sampling scope setups. 
A quick look in the Tek catalogs circa late 1980s to the 1990s should 
help to ID various models. Check the usual manual sites such as bama 
or ko4bb, or maybe even Tek has some info available. You may be able 
to get some more info if there are manuals available for these scopes


Also, if you plan to use it as an independent sampler, it will not do 
much on its own. Remember it's just the sampling head - a modular 
front-end that determines the performance, but only within the proper 
support environment. The scopes have the circuitry and smarts to 
operate the heads to get useful results. It is extremely far from 
trivial. The simplest way to use it would be to get one of the scopes.


As David suggested, the tekscopes group should be the best resource.

Ed
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Re: [time-nuts] 510 doubler

[Alexander Pummer]

And the narrow notch for the harmonic is not required anyway, since the 
fundamental is fare enough, therefore a high Q  LC trap will work 
better, also with the setting of the biasing af the active devices the 
spures could be reduced to [ just observe the output with a spectrum 
analyzer and set the bias of one site to minimum harmonics, there will 
be no common optimum for all harmonics, but a good compromise could be 
achieved ]

73
Alex KJ6UHN
On 1/29/2015 2:16 PM, Richard (Rick) Karlquist wrote:



On 1/28/2015 11:28 AM, Charles Steinmetz wrote:

Gerhard wrote:


It is a different game when you want to notch away sub/harmonics.


One problem with using crystals as traps (notch filters) is that the
series resistance of a crystal is several orders of magnitude higher
than that of a good series-resonant LC -- generally in the 50-100 ohm
range.  So, although the notch is very narrow, it will not be very deep
unless it is in a high-impedance circuit.  For example, in a 50 ohm


It is very straightforward to use LC networks to transform the
impedance of the crystal to a much lower value and get around this
problem.

Rick Karlquist N6RK
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Re: [time-nuts] tutorial on phase noise and PLLs?

[Alexander Pummer]

Hi Jim look here: 
http://www.gigatronics.com/uploads/document/AN-GT140A-Introduction-to-Phase-Noise-in-Signal-Generators.pdf
1981, /Dieter Scherer/, Generation of Low /Phase Noise/ Microwave 
Signals ... 1978, /Dieter Scherer/, Design Principles and Test Methods 
for Low /Phase Noise/ ... [http://www.hparchive.com/seminar_notes.htm ]

https://www.febo.com/pages/sevhfs_2010/Oscillator%20Phase%20Noise%20%28SEVHFS%202010%29.pdf
http://www.researchgate.net/publication/237674576_Generation_of_Low_Phase_Noise_Microwave_Signals
73
Alex
On 12/4/2014 11:41 AM, Jim Lux wrote:
I'm looking for a real short (3-4 slides or a website, really) 
description of why the phase noise of a PLL (microwave) looks the way 
it does, explaining (in sort of qualitative terms) how the phase noise 
transitions from the VCO (outside the loop bandwidth) to the reference 
(inside the loop bandwidth)..
And in particular, what the phase noise curve looks like if the loop 
bandwidth is chosen incorrectly, or if the VCO or reference has more 
or less noise than expected.




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Re: [time-nuts] Practical considerations making a lab standard with an LTE lite

[Alexander Pummer]

Schomandl -- the company which made the first indirect synthesizers in 
the sixties in the past century -- used buried crystal oscillators as 
standard frequency source, 12meter deep in the companies yard in the 
Belfort Strasse in Munich, Bavaria Germany, ...Rohde Schwarz also had 
buried oscillators. I have one in California, where, the temperature at 
10m deep is 15,784C° around the year, and measuring the frequency off 
set between wwvb's harmonic and the buried oscillator originally tuned 
to cca 3MHz, to the natural serial resonance of the crystal, by counting 
the beat -- to a harmonic of wwvb, cca 4217Hz , 364 358 801 pulses per 
day, as of Nov 2014, counter resets by wwvb daily, daily changes max ± 8 
pulses, are to see, but a yearly decrement of 15 to 8 pulses per year, 
less per year in the last time is observable the system down thereis 
running since 1991.

73
KJ6UHN
Alex


On 11/23/2014 8:46 AM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote:

On 23 Nov 2014 14:45, Bob Camp kb...@n1k.org wrote:

Hi

If you have a basement in your house / building

I do not.


—and —
it’s dry and reasonably draft free (no garage doors opening up from time

to time)

My lab is a room which is part of the garage! Just about everything is
against me with this method,  BUT you do give me an idea...

You got me thinking about the possibility of actually mounting the TCXO
burried in the ground!   The temperature of that is not going to change
very rapidly.

FWIW, I know a guy that did work as an air conditioning engineer,, but now
works for a company selling geothermal heating.  He installs  ground source
heat pumps for the geothermal energy.  He says that they actually work
quite poorly in many cases. In a couple of years the temperature of the
ground falls as the heat is extracted faster than it replenishes.  So the
efficiency falls off. I don't think that the TCXO would heat the ground
faster than it dissipates away.

Of course there would be some practical issues burying the TCXO, but those
would not be insurmountable ones. I have no idea what depth might be
needed.

My wife thinks thinks I am a nutcase - that would only confirm it to her!

Dave, G8WRB
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Re: [time-nuts] WWVB format

[Alexander Pummer]

Hi Paul,
the phase modulation would interfere with the AM, since during the phase 
change the narrow band crystal filter's output will sink down as the 
filter is following the phase change, and the time needed for the filter 
to swing in  to the new phase it depend on the angle of the phase 
change angle, for 180 degree it is 2 x [1/f] x Q  , [1/f] x Q needed to 
swing on and the same time to swing down from the old phase. 
[[RohdeSchwarz's old Q meter is based on that, it counts the zero 
crossings until the level of the signal sinks to ]]
and that causes an additional AM modulation, if the quartz filter of the 
clock  is not so good, the [1/f] x Q  time is shorter and the filter 
after the demodulator does not let it pass the amplitude change, thus 
the cheaper clock works better, until one switching mode power supply 
takes over the control from the WWVB

73
Alex

On 11/21/2014 7:17 AM, paul swed wrote:

Glenn
I want to say that my simple wwvb clocks are working. However my most
finicky one is not locked as I just noted. But then its always a problemed
child.
The format contains bpsk but that was not supposed to interfere with the
traditional AM modulation these clocks detect.
I might strongley believe that the various electronic lights that are
becoming pervasive is seriously deteriorating the ability to detect the
signal.
I am near Boston so thats fringe.
Regards
Paul
WB8TSL

On Fri, Nov 21, 2014 at 12:06 AM, Glenn Little glennmaill...@bellsouth.net
wrote:


Are there any atomic clocks that do not properly decode the current WWVB
format.
I have two that will not auto update the time and will troubleshoot if
this is not a format issue.

Thanks for any help.
73
Glenn
WB4UIV

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Re: [time-nuts] Mercury Ion Clock

[Alexander Pummer]

what power is need at 40GHz?
73
Alex
On 11/2/2014 4:44 PM, Magnus Danielson wrote:

Dave,

On 11/03/2014 01:29 AM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote:

On 1 Nov 2014 16:50, Jim Lux jim...@earthlink.net wrote:
behind a scintillator)


The 40 GHz stuff these days is not nearly as exotic as it used to 
be. The

challenge might be test equipment when you're debugging your 40 GHz
synthesis chain.

There's a fair amount of test equipment around to 40.0 GHz, but it is 
not

cheap even on the used market. But above 40.0 GHz it gets even more
expensive, as a lot of kit stops there. So a spectrum analyzer that 
works

to 40.1 GHz is going to cost serious money.

I don't know what ones chances of feeding 10.04 MHz into the 10 MHz
reference input to 40 GHz test equipment to make it work to
40*10.04/10=40.16 GHz. I suspect that you could get away with it.


It would not really be needed. Only if you would be using a 40,5 GHz 
oscillator and steer it, that 40 GHz would be exposed. However, I 
would not be surprised if a source in the 100 MHz to 1 GHz range or so 
would be used as an intermediary clock to a big 5 MHz fly-wheel. 
Naturally that intermediary could be synthesized. There are many ways 
to go about it.


Cheers,
Magnus
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Re: [time-nuts] Really fast ADC needed

[Alexander Pummer]

pipeline converter, but it needs as many clock period as the required 
bits, does he has the fast logic to deal with that amount of data?

73
KJ6UHN
Alex
On 10/29/2014 9:46 PM, Mark Sims wrote:

A friend of mine is looking for an ADC that can do 5 bits at 20-40 
gigasamples/second...  there is a timing related component to the project.  Any 
ideas of who makes a decent beastie?  It needs to supply continuous data so 
things like a fancy scope won't do...
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Re: [time-nuts] 10MHz Rubidium reference source for frequency counter

[Alexander Pummer]

Don't give up Karen, the Morion oxcos are relative easy to repair, you 
need one coca-cola can, cut it is pieces until you get a very thin ALU 
foil, get some thicker carton wind around the box of the OXCO's box that 
way you have a heat isolation between the OXCO's box and the vise, which 
you need to hold it, but hold the OXCO that way, that the bottom part 
where the soldering is fare away from the vise, and the can is upside 
down, fire up a relative large  [ min. 100W] solder iron, if it has 
temperature setting set to the maximum  and if it is hot push it hard 
against  the OXCO can, as soon as the solder melted push a piece Alu 
foil into the gap [ there is a gap between the bottom of the can and the 
rst of the can ] and move to the next part to melt the solder. You need 
to push in at least 5mm long the Alu foil into the gap, if you get it 
all around, you could pull out the content of the OXCO can.
That is a double oven oscillator, depend what is the problem , you may 
have to open the internal can also, usually it is visible if something 
is broken, just power up and follow the current paths, with meter and 
scope probe, it is practical to temporarily disconnect the oven heating 
[ the large heater transistor ].
I fixed five of them, you need some patience and luck and you have to be 
very careful.

73
KJ6UHN
Alex



On 10/29/2014 11:09 AM, Karen Tadevosyan wrote:

Charles,
Thanks a lot for the detailed explanation and recipes. Understood and will 
check this weekend.
All my Morion 10MHz MV89A OCXOs are used and from eBay's. That's why the first 
version of broken surplus MV89A looks realistic.
Best regards,
Karen




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Re: [time-nuts] Cheap Frequency chip with serial output

[Alexander Pummer]

Hi Paul,
 do you know about TDRs? I have a CSA803A with SD24 dual TDR head, 
which I did not used for at least five years, now I needed it and found, 
that in high resolution --below10psec --it became very noisy, [both 
channels] any idea? the box is cca 15 years old , power-supply?

73
Alex

On 10/26/2014 11:59 AM, paul swed wrote:

Alex thats quite a good answer to the problem with a wide selection of
solutions that account for the IFs and such,
Marullo looks like you have a solution. Even a choice of displays.
Regards
Paul
WB8TSL




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Re: [time-nuts] Some specs for MTI Millren 260 OXCOs

[Alexander Pummer]

Hi Pete,
 even a member of IEEE has to purchase it:

but don't give up yet
73
KJ6UHN
Alex



On 10/23/2014 2:04 PM, Pete Lancashire wrote:

Anyone have a IEEE account ?

http://ieeexplore.ieee.org/xpl/login.jsp?tp=arnumber=560251url=http%3A%2F%2Fieeexplore.ieee.org%2Fstamp%2Fstamp.jsp%3Ftp%3D%26arnumber%3D560251

-pete

On Thu, Oct 23, 2014 at 1:07 AM, Hal Murray hmur...@megapathdsl.net wrote:


dgmin...@mediacombb.net said:

The model 260 datasheet is on MTI's web site at

http://www.mti-milliren.com

That data sheet covers their standard models.  You can see the part number
in
the far right column of the table on the bottom of the last page of the
double page spread.  They are likely to have a few in stock.

They also make lots of specials.  Tell them the specifications you want and
they will make a new part number, put it into their system so you can
easily
order it, and keep the details private so your competitors have more work
to
do if they want to clone or reverse engineer your designs.

If the part number on a unit you get from eBay isn't on the data sheet,
it's
probably a special.  You can get a general idea from the data sheet but you
will probably have to measure it if you want the fine print.


--
These are my opinions.  I hate spam.



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Re: [time-nuts] Some specs for MTI Millren 260 OXCOs

[Alexander Pummer]

On 10/22/2014 1:57 PM, Scott Newell wrote:

At 03:43 PM 10/22/2014, Dave M wrote:

Content-Transfer-Encoding: 7bit

I contacted one of the MTI Milliren marketing guys a few days ago, 
and got
some specs on the MTI model 260-0624C and 260-0544C OXCOs that are 
currently


Be careful. I bought a couple of those $15 MTI 260-0544-C from a 
surplus dealer out in California. They were new, from the warmup 
performance we agreed that they were SC cut, and it sure looked like a 
double oven.


But...no EFC!



Hi Scott
may I get some copy of that datasheet?
thank you in advance
Alex
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Re: [time-nuts] What sort of oscillator is this?

[Alexander Pummer]

that is most likelly a TXCO, what is in the user's manual about warm up 
time? if they have a special precise reference -- like for spectrum 
analyzer or frequency counter that would have at least one magnitude 
better stability and would have OXCO,a good OXCO like the Milliren 260 
series or the double oven oscillators   from Morion [St Petersburg, 
Russia] ones --if they are always heated and have good power supply-- 
could have 3  x 10^-10 stability

73
Alex

On 9/27/2014 2:36 PM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote:

The 10 MHz high stability oscillator (option 1D5) in my HP 8720D VNA
has the following specs

Stability
0 to 55 deg C, +-/ 0.05 ppm
Aging per year +/- 0.5 ppm

What sort of oscillator is this likely to be -  TCXO or OCXO?


Dr. David Kirkby Ph.D CEng MIET
Kirkby Microwave Ltd
Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, Essex, CM3 6DT, UK.
Registered in England and Wales, company number 08914892.
http://www.kirkbymicrowave.co.uk/
Tel: 07910 441670 / +44 7910 441670 (0900 to 2100 GMT only please)
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Re: [time-nuts] Homemade GPS Receiver

[Alexander Pummer]

it is relative complicated, since you need to look multiple satellites 
almost in the same time

73
Alex

On 9/26/2014 5:12 PM, Hal Murray wrote:

he...@pericynthion.org said:

Since the GPS signals come from all parts of the sky this is pretty much
required, unless you're using fancy beam steering techniques.

How hard is the beam steering relative to everything else?




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Re: [time-nuts] WWVB d-psk-r down conversion method...

[Alexander Pummer]

there is an interesting side effect with that phase modulation: in case 
the crystal filter is narrow enough --to use for the old AM format-- 
the phase change creates an additional AM modulation, if you take in 
consideration that effect by the decoding the modulation, you could 
recover the time information despite of  the presence of the PSK.
Question: as fare as I am informed there is no chip/system available to 
correctly decode the new signal form, what was the purpose of the whole 
modulation format change?
The old AM format was happy with cca 200Hz bandwidth to recover the time 
information, which was utilized in many professional receivers, which 
used a crystal filter for 60kHz, for the PSK format the required 
bandwidth is at least five times wider, so crystal filter would be 
problematic and much more costly, the higher required bandwidth brings 
also more noise actually where is the advantage of the new 
modulation scheme?

73
Alex

On 9/23/2014 9:16 AM, Burt I. Weiner wrote:

Charles,

If I recall correctly, the original point of the d-psk-r was to cause 
the clocks to again read the correct time, not maintain their use as a 
frequency standard.  I have a Symmetricom 8170 that I used to use only 
as a clock to tell the time of day.  Since WWVB's addition of the PSK 
coding, it's only good to watch the pretty blinken lights.


Burt, K6OQK





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Re: [time-nuts] WWVB d-psk-r down conversion method...

[Alexander Pummer]

it could be that the intention was good , but there is no reliable 
atomic clock and the company which promised the chip still no t 
delivered any usable, as I learned from two of my clients which are in 
the were business of making atomic clocks

73
Alex

On 9/23/2014 11:06 AM, Charles Steinmetz wrote:

Alex wrote:

The old AM format was happy with cca 200Hz bandwidth to recover the 
time information, which was utilized in many professional receivers, 
which used a crystal filter for 60kHz, for the PSK format the 
required bandwidth is at least five times wider, so crystal filter 
would be problematic and much more costly, the higher required 
bandwidth brings also more noise actually where is the advantage 
of the new modulation scheme?


The changes were made to make today's consumer atomic clocks more 
robust, not to help any kind of professional receivers (whether time 
or frequency).


Best regards,

Charles



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Re: [time-nuts] WWVB d-psk-r down conversion method...

[Alexander Pummer]

Hi Brooke,
I hope that you are right with that chip, and despite the name change of 
the company -- now Xtendwave -- and recovering  they will deliver 
something some times. I can see that with correlation and averaging 
schemes the signal to noise ratio of data, perhaps constant frequency 
could be improved, but I would be very interested to see of the 
mathematical model of improving the signal to noise ratio of timing.

Regards
Alex


On 9/23/2014 1:08 PM, Brooke Clarke wrote:

Hi Alex:

Sometime in the future there will be chips that will decode the new 
signals (note the s on the end of that last word).  There are a 
number of frame times the longest one of which takes 17 minutes and is 
transmitted only once per day.  This format offers 23 dB modulation 
gain compared to the 1 minute time frame transmission that the current 
clocks use.  There are a total of 5 different modulation formats that 
will be transmitted over different time frames.  In the end everyone 
should have a clock with more frequent updates (on the West coast I 
might need to wait overnight for a clock to sync after a battery 
change) and more accuracy.

http://prc68.com/I/Loop.shtml#PhaseMod

Have Fun,



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Re: [time-nuts] Correcting jitter on the 1 PPS signalfrom a GPS receiver.

[Alexander Pummer]

depend how do you terminate the, cable if the cable's impedance is Z, 
use two terminating resistors each R =2Z, one is connected to thee 
ground the other is connected to the supply voltage of the receiving 
chip, that way although the cables input and output termination will 
eat up half of the signal voltage [since the two resistors at the end 
of the cable are for AC parallel and the two 2Z parallel is =Z  ], it 
will be still enough since the left over 2,5V level change will be 
centered at the threshold of the input device...

73
Alex

On 9/15/2014 2:48 PM, Bob Camp wrote:

Hi

These are saturated logic signals. When you terminate both source and load you 
get an interesting issue with compatible logic levels.

For instance: 5V CMOS switches at roughly 2.5V. If you series terminate and 
load terminate, your destination now sees a 0 to 2.5V signal. Either it’s 
running 2.5V CMOS and switching at 1.25V or you have a problem.

Bob

On Sep 15, 2014, at 9:03 AM, Dave Martindale dave.martind...@gmail.com wrote:


Is there any reason (other than cost) not to both series-terminate the source 
and parallel-terminate the sink?

When I was dealing with analog video, the standard distribution method was :

1. Buffer amplifier with high input impedance, very low output impedance, and a 
gain of 2 (so 1 V P-P input becomes 2 V P-P out)

2. A series 75 ohm resistor from the amp output to each individual video 
output.  This formed a 2:1 voltage divider with the 75 ohm coax to give 1 V P-P 
on the cable.  It also isolates the loads from each other.

3. A single video signal could be looped through multiple high impedance loads.

4. 75 ohm parallel termination at the far end of the signal path (usually on 
the last device).

This way, every device along the way saw an undistorted copy of the signal.  
The buffer amplifier sees a simple resistive load.  And any reflections are 
absorbed at both ends of the cable.

- Dave

On 15/09/2014 02:04, Fuqua, Bill L wrote:

A lot of devices have a low output impedance so that the signal can be split 
using a TEE adapter with little loss or need for a distribution amplifier.
However, the cables must be impedance matched at far end, scope input, to 
prevent reflections which are the source of the ringing.
You can match the impedance at the source and you will get a reflection which 
will then be absorbed by the source resistance. One way to do this
is to get a small 15 turn pot about 100 Ohms put it, in series with the input 
source and adjust it until the ringing is gone or you can put it at the far end
,input of the scope, to ground and do the same.  But the best solution is to 
get a good feed thru 50 Ohm terminator and put it on the input of the scope.
Bill



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Re: [time-nuts] Is a crystal likely to change frequency by 3% ?

[Alexander Pummer]

there is only one magnet, which drives the fastest moving arm -- the 
pointer for the seconds -- the other arms are connected via gears, by 
the way that case with the weak periodically recovering battery is an 
observed one, I connected a paper chart recorder to the clock  and 
recorded the battery voltage change and the driver pulses of the magnet 
-- the recorder was not able to follow the individual pulses, but the 
envelope

73
Alex


 On 9/13/2014 5:08 AM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote:

On 13 Sep 2014 01:23, Alexander Pummer alex...@ieee.org wrote:

just open the box, look for the wires which going to the magnet which

drives the minute hand and measure the period time -- not the frequency, it
is to low

yes analog quarz clock slows down as the battery get old,  you will be

surprised, that the driver pulse's period time dos not change, but
sometimes the divider chain or the mechanic skips a pulse, as the battery
voltage drops further suddenly the clock mechanic or the electronic will
stop working, takes less current so the battery recovers a bit, because the
magnet did not used power for a while, and will run again for a while, the
pause between two run time will be larger and larger so the clock looks
like going slower

73
Alex

So if it the mechanics skips a pulse,  one really needs some method of
measuring the position of the hands and recording that.

In any case, the explanation you give is different to Dave McGuire.

Maybe the second hand is more likely to slip if trying to fight gravity
(between 30 and 0 seconds) and less likely when gravity helps (between 0
and 30 seconds)

It would be interesting to see a detailed study of this.

Dave
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Re: [time-nuts] Is a crystal likely to change frequency by 3% ?

[Alexander Pummer]

just open the box, look for the wires which going to the magnet which 
drives the minute hand and measure the period time -- not the frequency, 
it is to low
yes analog quarz clock slows down as the battery get old,  you will be 
surprised, that the driver pulse's period time dos not change, but 
sometimes the divider chain or the mechanic skips a pulse, as the 
battery voltage drops further suddenly the clock mechanic or the 
electronic will stop working, takes less current so the battery recovers 
a bit, because the magnet did not used power for a while, and will run 
again for a while, the pause between two run time will be larger and 
larger so the clock looks like going slower

73
Alex

On 9/12/2014 3:52 PM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote:

Dr David Kirkby
Managing Director
Kirkby Microwave Ltd
Registered office: Stokes Hall Lodge, Burnham Rd, Chelmsford, Essex, CM3
6DT, United Kingdom
Registered in England and Wales as company number 08914892
http://www.kirkbymicrowave.co.uk/
Tel 07910 441670 / +44 7910 441670 (0900-2100 GMT)
On 12 Sep 2014 12:18, Bob Camp kb...@n1k.org wrote:

Hi

Hi,


If this is an RTC, it’s probably running off of a battery when the

machine is powered down. It is far more likely that the oscillator is
dropping out (stopping) rather than shifting frequency.

Good point,  I never thought of that. I have however noticed that analogue
quartz clocks slow as the battery goes flat. But maybe too they stop and
start. It would make an interesting experiment to check it, but one would
need some method of logging the time from the hands.  Conceptually that is
not difficult,  but it needs more work than I want to do. One could do it
with a video camera and a fair bit of work writing the software. Probably
easier is logging battery voltage and current as that should show if it
starts and stops.
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Re: [time-nuts] Eureka, no more Cs, active or passive H-masers or GPSDOs needed

[Alexander Pummer]

and if you look the claims  of the patent, they are very close to the 
Shera design, which was a bit earlier idea

73
KJ6UHN
Alex

On 9/10/2014 10:12 AM, iov...@inwind.it wrote:

On Tue, Sep 9, 2014 at 4:26 AM, Azelio Boriani azelio.bori...@screen.it
wrote:


Take a look at this patent
http://www.google.com/patents/US20130342278 and you will learn how
to build the ultimate time and frequency reference.


The patent's owners don't appear to be very trustful in their idea, as they
sell only a GPSDO as a time reference:

http://www.onetastic.com/en/onetastic-otgps1.php

Antonio I8IOV
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Re: [time-nuts] Oscilloquartz 3210 Cesium Standard

[Alexander Pummer]

yes I got these executable too, and therefore did not continued
73
Alex
On 9/9/2014 5:59 AM, paul swed wrote:

Ohhh that hurts and you were lucky. I always mark connectors for that exact
reason. I was going to download the pictures but it kept trying to download
some executable. So will not be able to look at your pictures.
Regards
Paul.

On Tue, Sep 9, 2014 at 4:35 AM, Adrian Constantinescu 
adrian.valentin.constantine...@gmail.com wrote:


Did a major breakthrough!
Obviously it was my fault, by mistake i swapped two connectors.
  My luck is that the power board has some safety elements.
OK,  now with the connectors in correct position
I have 8.5 and 17 volts on the outputs.

Getting closer

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Re: [time-nuts] Need help with transformer core

[Alexander Pummer]

forward converter [not fly -back]
look for pot-cores material 3C80, 3C81, 3C85 or equivalent, you will 
need  a cca 21 to 28mm dia pot-core if you run it at 80 to 120kHz, 
driver ic TL495 , which is a PWM push pull controller
estimate the efficiency for 60% for the input power, look for very good 
and large 10Megohm resistors you wil nee four of them 3700V/01mA = 37 
Meg ohm, the must be temperature stable and must be able to carry 1000V 
each, you need a high quality resistor for the bottom part of the 
feedback divider same sort as the 10Megohms  value cca 57k use 56k + an 
1k pot.
Philips has fast high voltage rectifiers you need some with very short 
recovery time

how to design a transformer:
http://www.google.com/url?sa=trct=jq=esrc=ssource=webcd=1ved=0CCMQFjAAurl=http%3A%2F%2Fwww.mag-inc.com%2FFile%2520Library%2FProduct%2520Literature%2FFerrite%2520Literature%2FMagneticsFerritePowerDesign2013.pdfei=RTUFVOKzIMn3igLAoYGgBQusg=AFQjCNE63ziQj-MYzYmYzNfLrHThFJu1lgbvm=bv.74115972,d.cGE

a more elegant way is a resonant converter, less noise, less 
complicated  high voltage transformer, and the recovery time is not so 
critical,  but that is for more experienced DIY people

73
Alex

On 9/1/2014 3:54 PM, Chris wrote:

Thanks for the inputs everyone,

One of the direct replies got me the data I needed!

Alex, I'd like to by it that way, but A 24VDC input 3700VDC output at 
4ma

does not seem to be available!

Cheers,

Corby


Hi Corby,

The way I would approach the problem would be not ask where to get a 
given pot core, but how do I generate 3700v @ 4mA, starting from 
scratch. I would limit the secondary winding count and use a voltage 
multiplier, Cockroft-Walton style to bring the volts up to the 
required level. 22w is not an insignificant power level, so I would 
use a switch mode regulator chip, driving a pair of small power 
mosfets, with a switching frequency 100KHz or higher to keep the 
magnetics, winding turns count and the multiplier (Use polypropylene) 
caps small. Lower voltage at the secondary also makes it easier in 
terms of rectifier diode selection. All the info is in the chip 
manufacturers application notes. and suggest Unitrode as a starting 
point. Have done a few of these in the past and they are pretty 
strightforward. Even the magnetics are covered by the core 
manufacturers data books. A pair of small E cores sounds sounds about 
right and will have matching moulded bobbin options with tags. Pot 
cores are a pita in comparison and awkward to wind / terminate using 
foil, which you really need when a primary winding may only have 4 to 
8 turns, yet be carrying amps.


The other point is that I would never use any switcher, however good 
it's claimed to be, to drive sensitive analog electronics. While many 
of the cheap switcher modules are fine with stable line and load, the 
transient response ids often dreadful and they take some time 
(milliseconds) to recover with step function change at either. Such 
instability can damage driven electronics as well. While it's common 
to use a switcher for initial conversion, that would always be 
followed by monolithic linear regulators, which typically have output 
noise levels of mV. For example, say you have an input voltage of 
18-32v and a required output of 12v at 1A, an initial switch mode 
regulator to convert to 15v, then even a 7812 or similar to lose the 
final 3 volts...


Regards,

Chris
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Re: [time-nuts] time-nuts Digest, Vol 121, Issue 65

[Alexander Pummer]

actually if the oscillator is stabil enough, with a very long time 
constant one could kill the phase modulation of the new WWVB format

73
Alex


On 8/23/2014 6:27 PM, Bob Camp wrote:

Hi

If you lock an Rb to GPS, you need / want / should do it with a *very* long 
time constant. Numbers in the one day to several days range are commonly seen. 
If you lock it up with a tighter (shorter time constant) loop, it will just 
wander around as it follows the GPS input. That’s what would happen if you hook 
your Rb to your Trimble and turn on the disciplining on the Rb. It will 
significantly degrade the stability of the Rb.

If you have a temperature stable environment (or create one) you can get some 
very good results with an (good) Rb locked to a (good) GPS via a proper long 
time constant setup. It’s not easy, but it can be done.

Bob


On Aug 23, 2014, at 6:31 PM, Ed Palmer ed_pal...@sasktel.net wrote:


Hi Dave,

On 8/23/2014 3:51 PM, Dave M wrote:

Thanks for that suggestion, Ed.  After a bit of reading in the X72 Reference 
Guide, it appears that the X72 does have a 1PPS input.  That would be 
considerably easier than trying to interface the Rb into the GPSDO.  Still 
trying to understand what the manual is telling me. Next thing is to determine 
if my unit has that option enabled (firmware option).  That will be a chore for 
after the holiday... really busy next week.

What would that (1PPS disciplining) do for me... in terms of maintaining the Rb 
frequency accurately set?  Would it be as accurate as having the Rb disciplined 
via the EFC input?

It's kind of overkill, but by connecting the 1 PPS from the NTBW50AA to the 
X72, the X72 will be disciplined to the 1 PPS so the frequency will be 
accurate.  The question is how well will it be disciplined, i.e. what will the 
Allen Deviation graph look like.  I have a few X72 and SA-22c (X72's cousin), 
but none of them have that option.  I don't know of any published data on it.  
Maybe you can tell us how well it performs.

In general, I just don't see the point of disciplining a Rb standard to GPS.  I 
don't understand what will be gained by doing it.  I have a Z3801A and a Tbolt 
plus a free-running FRK as a house standard.  I occasionally compare the FRK to 
the Z3801A but the drift is so low (~1e-12 per month over 9 months) that I see 
no reason to link them.

One exception that I recently discussed on another forum was a guy who lives in 
a ground floor, north-facing condo.  He might need to have a disciplined Rb 
standard due to poor GPS visibility.

Ed


Thanks,
Dave M



Message: 5
Date: Fri, 22 Aug 2014 16:19:45 -0600
From: Ed Palmer ed_pal...@sasktel.net
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Subject: Re: [time-nuts] EFC info on Trimble 34310-T OXCO
Message-ID: 53f7c201.5070...@sasktel.net
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Have you checked your X72 to see if it has the 1 PPS discipline
option?
That would be a lot easier (and probably better) than your proposed
transplant.

Ed

On 8/22/2014 12:39 PM, Dave M wrote:

Does anyone have any info on the OXCO in the Nortel/Trimble
NTBW50AA-17 GPSTM receiver?  The OXCO is labeled as Trimble 34310-T.
I see some Trimble 34310-T oscillators on Ebay with pinouts labeled,
but no other info.

Specifically, I'd like to know the EFC characteristics for it.  I'm
thinking of the possibility of pulling the OXCO out of the GPSTM and
subbing in a 10 MHz Rubidium, and using the GPSTM to discipline the
Rubidium.  My Rubidium is a Symmetricom X72, recently purchased.  It
seems to be working well.
Does anyone know the differences between the three OXCOs used in the
GPSTM receivers (T, T2 and Oak)?

Thanks for some insight,
Dave M

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Re: [time-nuts] Cutler NAA on 24.0kHz....

[Alexander Pummer]

if you use analog way to divide the 120kHz that will prevent an 
incidentally flip of the phase

73
Alex
On 8/17/2014 2:21 PM, paul swed wrote:

Robert
Yes indeed the lm3900 is a great part. The last opamp is a 100hz BPF.
The RCs perform a phase shift and I will tend to believe that at the
bandpass filter it is a full wave rectified signal. Only a guess.
Here is the part I don't get. How does that remove the msk? Mask is FSK and
you can see the shifts in spectrumlab.
Rick per your comment yes the doubling of the carrier does remove the BPSK
that was the earliest approach studied applied and then rejected as when
teh carrier was returned to 60KHz any method used left an ambiguity that in
fact could flip randomly due to noise. Not pretty on the strip chart.
But back to this its msk. I am missing the secret math or something.
Do I believe this will work if I build it. Absolutely and a 24 Khz rcvr
ain't all that bad to build.
Regards
Paul
WB8TSL/1


On Sun, Aug 17, 2014 at 4:35 PM, Robert LaJeunesse lajeune...@mail.com
wrote:


It's simple, but not obvious. The LM3900 is a Norton amplifier, and while
it has differential inputs they are current driven. (Most older op amps are
voltage driven.) The LM3900 is powered from 10V, so I think of that as just
above the maximimum output voltage. Both the upper amplifier and the second
lower amplifier have 1M feedback resistors, and + inputs fed 10V by 1M bias
resistors. That would bias the output at near the supply rail, turning
these stages into something like half-wave rectifiers. Since the first
lower stage has a 2M bias resistor it idles at about half supply, and
behaves as a simple inverter. If my analysis is correct (and I worked at
National when the LM3900 came out, a friend did apps for this odd new part)
then the combining of the two outputs produces a negative going full wave
rectification of the signal. The fourth LM3900 stage looks like an
inverting bandpass filter, but I'd have to dig out some reference books to
determine its behavior in more detail. As for the 100-200 switch I'm
confused, why would the bandpass frequency be lowered for the higher
modulation rate?

Bob LaJeunesse


Sent: Saturday, August 16, 2014 at 2:56 PM
From: Kenneth G. Gordon kgordon2...@frontier.com
To: paul swed paulsw...@gmail.com
Cc: time-nuts@febo.com
Subject: Re: [time-nuts] Cutler NAA on 24.0kHz
On 16 Aug 2014 at 13:35, paul swed wrote:


Kenneth on the opamps that is correct.
But I put little U's to indicate phase. They actually represent the top

half of

the input cycle.

Yes, I saw those, but unless I am mistaken, you didn't add a U after the
second opamp, which would have returned the phase to the input's.


In the top path it inverts once.

I see twice: once through the first op amp and again through the second
one.
The second one then outputs to the IF.

Anyway, to me, it is a very interesting and simple circuit.

I LIKE simple. I am a great believer in the KISS principle.

Ken W7EKB
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Re: [time-nuts] WWVB for Time Nuts

[Alexander Pummer]

Actually, why was the WWVB modulation format changed, before a  
functioning new transmission system was at least demonstrated? Since the 
new --supposed to be superior --system exist on paper, if  at all only, 
but not available to replace a more or less usable usable one.

73
Alex

On 8/10/2014 8:14 AM, Dale J. Robertson wrote:

Hi,
How does patent infringement litigation get started anyway?
I would think that the infringement claim would have to be specific 
i.e. you are infringing on our patent number blah, claims blah, blah, 
blah  blah. not just you are infringing on our patent. you need to 
halt production immediately and can't resume until you have properly 
guessed how you are infringing and stop, or, pay us a crapload of money.
AFAICT, the patent includes no claims regarding conventional BPSK 
detection and demodulation. The patent seems to be about arranging the 
bits in a 'more efficient' way that, when taken advantage of by the 
receiver described in the patent, makes possible a 20dB process gain 
over a conventional AM envelope receiver.
I am having a difficult time imagining a conventional receiver design 
(even one implemented in DSP) that would infringe on this patent.
In at least one of their papers they even contrasted their receiver 
architecture to a conventional BPSK receiver.
All that being said, I suspect that there is no real market for a WWVB 
based timing product. Even before the modulation change there were no 
commercial WWVB based timing products, and there hadn't been in 
several years.
So, If you want to buck the trend and make such a product, You can 
probably do so without much fear of someone coming after you.
I suspect though that 5 years hence you will be able to hold your 
equipment users group meetings in a room the size of a broom closet. 
And that’s assuming you are still using yours!

Dale

-Original Message- From: Bob Camp
Sent: Sunday, August 10, 2014 8:41 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] WWVB for Time Nuts

Hi

Keep in mind that it’s relatively cheap (big company wise) to get a 
patent. It’s only got major value once the courts uphold it as valid. 
That process costs real money. I’ve seen a variety of estimates on how 
many patents get issued that would never stand up to challenge. None 
of the estimates I’ve seen have been below 50%, some are a lot higher. 
Since the patents for sunscreen that’s only useful on the moon also 
get tossed into some of the estimates, who knows what the real numbers 
are.


Often the protection process becomes a “we have 689 patents on this 
gizmo” sort of thing. Even if 99% of them are bunk, it will cost you a 
lot to prove that. You still would have to pay based on the 1% that 
turn out to be valid. The net result is a system that never challenges 
(and clears out) the junk.


Bob

On Aug 10, 2014, at 4:24 AM, Dr. David Kirkby (Kirkby Microwave Ltd) 
drkir...@kirkbymicrowave.co.uk wrote:



On 10 Aug 2014 05:39, Jim Lux jim...@earthlink.net wrote:


(but, I gotta say that a lot of the patents that get published in the

back of things like IEEE Ant and Prop Magazine seem, to me, to be pretty
obvious..)

I have not looked at patents recently,  but most I have looked in the 
past

are  fairly obvious to someone skilled in that area. Another large group
appears to be useless things.

Perhaps time-nuts should stick on a web site a list of 100 obvious 
things

that they believe someone might just try to patent.  Once an idea is
disclosed like that, it should stop a patent being issued. Perhaps a
braille clock with an internal atomic frequency reference. I don't 
suppose
anyone has made one, as the demand would be low, but it is in my a 
opinion

fairly obvious approach for a skilled person.

I assume there is some time delay (probably in the range 100 us to 10s)
between one observing a clock and one's brain decoding it. So for a 
person
to believe that they know the time, the clock actually has to display 
it a

bit fast.

But more seriously,  one could probably have some impact on time nut
related patents by documenting semi obvious things on a web site in
advance.

I recall being at the patent office in London and see someone had a 
patent
on a screen built into a microwave oven hooked upto a video camera so 
you

could check on the security of your premises while cooking.

I guess with China pretty much ignoring patents, it might become more
attractive to keep something a trade secret rather than patent it.

I believe Samsung and Apple have recently agreed to drop patent
infringement cases against each other outside the USA

http://www.forbes.com/sites/amitchowdhry/2014/08/06/apple-and-samsung-drop-patent-disputes-against-each-other-outside-of-the-u-s/ 



I know BT and Marconi did a similar thing, as I guess that they realised
that they were spending an excessive amount of money fighting each other
over patent infringement.

Dave.

Re: [time-nuts] WWVB BPSK patent status

[Alexander Pummer]

look that also:
48 Ultra-accurate DSP-based
DCF77 Timecode Receiver
To extract the highest possible accuracy from the German DCF 77.5
kHz time
-
code broadcast this project uses DSP algorithms running on a low-cost 
dsPIC33

microcontroller to filter and demodulate both the AM and phase modulated
signals, while also producing a very stable 10
Hz carrier-locked reference clock
output.

http://uploadkon.ir/uploads/4b5782ba531bb58ff30ceeaa383a9212.pdf

On 8/8/2014 5:20 PM, Paul Davis wrote:

How about these Xtendwave patents for a start:

8270465 - Timing and Time Information Extraction from a Phase Modulated Signal 
in a Radio Controlled Clock Receiver
8605778 - Adaptive radio controlled clock employing different modes of 
operation for different applications and scenarios
8774317 - System and Method for Phase Modulation Over a Pulse Width 
Modulated/Amplitude Modulated Signal for Use in a Radio Controlled Clock 
Receiver
Application number: 20130121399 - Timing and Time Information Extraction in a 
Radio Controlled Clock Receiver
And patent 8300687 of the same name but issued Oct 2012?

Or did you mean Heath Co.? The only thing relevant there is 4582434 - Time 
corrected, continuously updated clock but that is for WWV/WWVH not WWVB. And it 
was granted in 1986, so no longer in effect anyway.

Paul

On Aug 8, 2014, at 6:24 PM, Brooke Clarke bro...@pacific.net wrote:

Hi Mike:

Do you have any patent numbers.

Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
http://www.prc68.com/I/DietNutrition.html

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Re: [time-nuts] WWVB BPSK patent status

[Alexander Pummer]

also there is one FPGA based system already available unfortunately the 
description is in German : 
http://www.cadt.de/dieter/dcf/Praezisionsfrequenzmessungen.pdf


 On 8/8/2014 5:33 PM, Alex Pummer wrote:
there was a Swiss ingenieur who designed and published a receiver 
design for the DCF77 which has the same modulation format, also there 
was a Finish design a few years ego also published, therefore, that 
American company, which is promising the chip for a while but instead 
delivering the chip changes it's name... has to be very careful with 
patent writing.

73
Alex

On 8/8/2014 4:44 PM, Richard (Rick) Karlquist wrote:

Without having seen the specific patent, what
worries me is that there is a trend these days
to write blanket patents that say you can't
build any black box that, for example, receives
this format, no matter how it works.
They don't have to prove what is
in your FPGA code.  They then can shut down any
competition with such a weak patent unless the
competition has deep pockets for a lawyer.  If
they can prove you willfully infringed (whatever
that means), they get triple damages.  If you
do any kind of patent search, do not keep any
records or tell anyone about it.

Possibly you could make the FPGA code available
on the internet and have the end user be the
infringer.  Not being a lawyer, I'm not sure
if this would get you off the hook.  Maybe
they can hang their hat on the digital copyright
law (DCMA?) , in which case you become a criminal too.

Rick Karlquist N6RK

On 8/8/2014 3:24 PM, Brooke Clarke wrote:

Hi Mike:

Do you have any patent numbers.

Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
http://www.prc68.com/I/DietNutrition.html

Mike Harpe wrote:

From my reading of the archives and research it appears that the
design for
a BPSK WWVB receiver probably has a patent conflict.

Isn't this a rehash of the old Heathkit patent on radio clocks that 
held

back their adoption for years?

I have begun work on a BPSK receiver for WWVB using an FPGA.

Someone should look into why the NIST did this at all since the 
receiver

design got a patent slapped on it right away.

Mike Harpe, N4PLE
Sellersburg, IN
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Re: [time-nuts] Low noise powersupplies

[Alexander Pummer]

to measure a power supply noise, better to say the noise spectrum,  you 
would need a very large non polarized capacitor and spectrum analyzer, 
The input of the spectrum analyzer does not like DC, and has low 
impedance. Since spectrum analyzer's input impedance is usually 50 ohm, 
for to be able to see the noise at low frequency you need  C = 1/( 2 x 
3.14 x 50 ohm x f Hz ) capacitor, and you would need a DC level limiter 
to prevent blowing the input of the spectrum analyzer during the charge 
up of that capacitor. If you could get a hold of an old HP 1Meg to 50ohm 
buffer amplifier you would need much lover capacitance or if  the buffer 
has AC input capability with low enough corner frequency like  the 
Tektronix P6201 FET probe, you would not need any capacitor. And that 
would make your life much nicer since capacitors could generate noise to..
Charles Wenzel  in his circuit collection files ha very nice good 
working noise reduction circuits.

73
Alex
KJ6UHN

On 8/7/2014 1:41 PM, Chris Albertson wrote:

Just practical question..

How would one measure noise at this level?  If I were evaluate this what
would I need?  My scope lacks a nV/dev setting so is there some way to tell
the difference between this and an LM317?  Seriously, what kind of
instrumentation would I need before I could measure an improvement over my
standard LM317



On Wed, Aug 6, 2014 at 11:38 PM, Ole Petter Ronningen olep...@gmail.com
wrote:


Hello, all

I thought it may be of interest to some of the members of this list that TI
is selling evaluation modules for some ultra low noise regulators for $20
in their estore, shipping world wide included. The specs looks pretty
decent to me, and I've ordered up a couple of boards to use as clean up
boxes for my bench-supplies, to use on noise-sensitive projects.

1.4-30v output TPS7A4701EVM-094
3.5µVRMS (10Hz, 100KHz)
25 nV/√Hz (10Hz, 1MHz)
Maximum Output Current of 1A

+-15v version TPS7A30-49EVM-567:
15v rail:
Noise:
  12.7µVRMS (20Hz to 20kHz)
  15.4µVRMS (10Hz to 100kHz)
Power-Supply Ripple Rejection:
  72dB (120Hz)
  ≥ 52dB (10Hz to 400kHz)
Maximum Output Current: 150mA


-15v rail:
Noise:
  14µVRMS (20Hz to 20kHz)
  15.1µVRMS (10Hz to 100kHz)
Power-Supply Ripple Rejection:
  72dB (120Hz)
  ≥ 55dB (10Hz to 700kHz)
Maximum Output Current: 200mA

Ole
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Re: [time-nuts] Low noise powersupplies

[Alexander Pummer]

people who designing low noise PLLs solved that problem a while ego go 
to Charles Wenzels circuit collections he made a very low noise from DC 
to a few hundred kHz amplifier just to amplify the phase noise, here is:

http://www.techlib.com/files/lowamp.pdf


On 8/7/2014 5:05 PM, Bob Camp wrote:

Hi

A low noise chopper stabilized op amp can make a pretty good pre-amp to put in 
front of a low frequency spectrum analyzer. Something in the 20 to 30 db gain 
is adequate for most analyzers. That will get you down to a level that’s well 
below the noise floor on any OCXO I have ever seen.

Here’s a way to look at it:

The input resistors on the OCXO have KBT noise (they are real resistors). They 
also are in the “many thousands of ohms” range. If you short the EFC (zero 
noise in) you still have resistor voltage noise modulating the EFC. All you 
need to do is to get down to the KTB level in a few thousand ohm resistor.

Yes 1/F noise does get into the mix. That’s why you want the chopper.

Bob
  
On Aug 7, 2014, at 6:32 PM, Alex Pummer a...@pcscons.com wrote:




the PC sound card has limited bandwidth   bellow 20Hz and above 20kHz, is nothing and 
also it is not so noise less like a spectrum analyzer which was made to 
analyze spectrum and the sound card self is in a relative noisy environment in the PC

On 8/7/2014 3:09 PM, Bob Stewart wrote:

What about a PC sound card?




  From: Alexander Pummer alex...@ieee.org
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Thursday, August 7, 2014 5:06 PM
Subject: Re: [time-nuts] Low noise powersupplies
  
to measure a power supply noise, better to say the noise spectrum,  you

would need a very large non polarized capacitor and spectrum analyzer,
The input of the spectrum analyzer does not like DC, and has low
impedance. Since spectrum analyzer's input impedance is usually 50 ohm,
for to be able to see the noise at low frequency you need  C = 1/( 2 x
3.14 x 50 ohm x f Hz ) capacitor, and you would need a DC level limiter
to prevent blowing the input of the spectrum analyzer during the charge
up of that capacitor. If you could get a hold of an old HP 1Meg to 50ohm
buffer amplifier you would need much lover capacitance or if  the buffer
has AC input capability with low enough corner frequency like  the
Tektronix P6201 FET probe, you would not need any capacitor. And that
would make your life much nicer since capacitors could generate noise to..
Charles Wenzel  in his circuit collection files ha very nice good
working noise reduction circuits.
73
Alex
KJ6UHN
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Re: [time-nuts] Tektronix TM500 extender cable kit

[Alexander Pummer]

that is one empty e-mail Robert LaJeunesse did not write anything into it
73
Alex
KJ6UHN

On 8/6/2014 5:17 PM, Robert LaJeunesse wrote:

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Re: [time-nuts] Effects of noise on EFC line?

[Alexander Pummer]

and use not to large capacity, because above the serial resonance 
frequency [trace inductance, own inductance] it will be inductive!

73
Alex
KJ6UHN

On 8/5/2014 12:16 PM, Jim Harman wrote:

I was able to quiet things down a lot by putting a 100 ohm resistor in
series with the 74HC output. If these guys drive more than a few inches of
wire, they ring like crazy. Also make sure you pay close attention to the
bypassing of the 5V supply. Make your bypass cap lead lengths as short as
possible.


On Tue, Aug 5, 2014 at 2:36 PM, Bob Stewart b...@evoria.net wrote:


I've run into a noise problem on the EFC line of my GPSDO engine at the
frequency of the oscillator.  I've traced the source down to the 74HCT365
I'm using to output the 1(or 5)MHz and 10MHz signals.  When I pull it, the
EFC quietens down a lot.  I'm seeing about 50mv of 10MHz noise at the
output of the op-amp that feeds the EFC voltage divider at the OCXO.  The
voltage divider is corrected by the VRef from the OCXO with a simple
circuit using temp-co'ed resistors.  On the 0.1uf cap at the OCXO's EFC
pin, I'm seeing about 5mv of 10MHz signal.


I've considered switching the HCT out for a 74LS365, assuming my drive
levels are compatible.  Unfortunately, I don't have one in stock, and
I'm way out of my pay grade, as they say.  I've also thought about
putting a 100uh inductor in series with the EFC line.  I wonder if I'll
have to isolate the 74xx365 chip's VCC through an inductor?  Any thoughts?


I'm also wondering what the impact of this level of on-frequency noise
will be?  Is the impact somewhat mitigated, since it's at oscillator
frequency?  I don't have anything better than an HP 8558B to look at the
output of the board.

I'm not quite ready to generally share my schematic with the list, but I
can make individual exceptions.


Bob - AE6RV
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Re: [time-nuts] OT Gel Cell question

[Alexander Pummer]

as long as it is not a gals/ceramic seal, there is no way to stop 
sulfuric acid to get out from the cell, just imagine the dilatation 
diffrence between plastic and metal...

73
Alex

On 7/28/2014 10:12 AM, Ed Palmer wrote:
As I understand it, the only time that any sealed lead acid battery 
will vent is in the case of gross overcharging.  The battery is 
designed so that normal charge rates and correct float voltage will 
result in recombination of any hydrogen and oxygen produced. Was there 
a fault in the charging circuit or perhaps, the charging circuit 
didn't have proper temperature compensation of the charge voltage?


Ed

On 7/28/2014 10:56 AM, Brooke Clarke wrote:

Hi:

Using lead acid batteries and a precision frequency standard is not a 
good thing if they are too close together.


A number of decades ago (before the Time Nuts or the internet) I was 
able to purchase a rack mount Gibbs 5 MHz double oven frequency 
standard that used a very nice Bliley glass tube crystal because it 
was not as precise as is was supposed to be. It used GelCell backup 
batteries that were physically in the same rack chassis as the oven.  
The fumes from the batteries when charging etched some traces off the 
PCB inside the oven defeating the temperature control but leaving the 
oscillator. It took a long time to reverse engineer and repair it.  
I've added a photo of the cord wood construction of the cylindrical 
oscillator.  The core of the cylinder holds the glass bottle crystal 
and the glass piston coarse tuning capacitor, surrounded by the first 
heater, circuitry for the oscillator and dual temperature control 
circuits on ring shaped boards.  These fit inside a cylindrical 
cavity which is the outer oven.  I've added a photo of the inner 
assembly at:

http://prc68.com/I/office_equip.html

Have Fun,

Brooke Clarke


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Re: [time-nuts] Synergy-GPS SSR-6tru Problem Resolved

[Alexander Pummer]

Synergy's owner Ulrich Rohde N1UL --DJ2LR/DL1R is a long time ham radio 
operator, and he will go pretty far to help for an other ham,

73
KJ6UHN ex DL...
Alex

On 7/25/2014 5:27 PM, Bob Stewart wrote:

And while this subject is still up, I want to let the group know that Synergy 
*really* went out of their way to help me with this.  I was a bit surprised at 
their level of commitment to some ham radio operator who had bought a single 
unit from them and probably didn't know what the heck he was talking about.  A 
real class act all around!

Bob - AE6RV




  From: Art Sepin a...@synergy-gps.com
To: Bob Stewart b...@evoria.net; Discussion of precise time and frequency 
measurement time-nuts@febo.com
Cc: Tom Van Baak t...@leapsecond.com; Dusty Morris doxielove...@cox.net
Sent: Friday, July 25, 2014 5:17 PM
Subject: RE: [time-nuts] Synergy-GPS SSR-6tru Problem Resolved
  


Bob,

Once in a while a mea culpa is required and we're posting it here so everyone 
understands our commitment to the users of Synergy's products.

The Original Synergy Adaptor Board was designed to allow Motorola's newer 3 
volt 12 channel M12+ to plug into an older 5 volt 8 channel UT+ slot. That 
product worked for hundreds of users over the years until (we found out through 
your personal aggravation and agony) the recent introduction of Synergy's SSR 
series of u-Blox based precision timing boards.

To make sure that the Synergy UT+ Adaptor Board issue is put to bed properly we 
asked for an external, formal technical review of this product that was 
introduced fourteen years ago.

The reviewing engineer's first comments were Ouch! This will not work.  And, no, the SSR 
boards do not work the same as the M12 boards on the Synergy Adaptor Board. The M12+ and M12M 
receivers have separate serial ports for the two functions (Receiver command RxD and DGPS RxD input) so it 
does not matter what you do with the RTCM port, pin 5 on UT+ connector and pin 8 on the M12+/M12M connector, 
if not in use with an M12x receiver.

The SSR boards, however, had to combine the two serial data streams expected by the 
M12x navigation receivers into one because the u-Blox receiver modules only use one 
serial input port for both receiver commands and DGPS correction data. The Synergy 
Adaptor Boards use a simple gate combiner circuit that worked well when using the M12+ or 
M12M but left Synergy open to this problem when using an SSR. Both serial lines on the 
SSR board, pins 2 (Receiver RxD) and 8 (DGPS RxD) are pulled high on the SSR board so 
open pins are OK but they must not be grounded.

The solution is for Synergy to make a UT+ Adaptor Board part number available to 
users who only want to test the features of SSR timing receivers.

That new SSR only Adaptor Board part number, which we'll have available in a 
few days, will remove R3 (4.7K) and R4 (6.8K) from the adapter board and the 
compatibility issue will be resolved. In the interim, other users can pull pin 
5 of the UT+ connector high (+5V) as you did.

We apologize for the confusion and frustration, Bob, and thank you for the 
valuable feedback!

Art Sepin
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Re: [time-nuts] Synergy-GPS SSR-6tru Problem Resolved

[Alexander Pummer]

Ulrich's Father, professor Lothar Rohde was my boss, Ulrich owns a part 
of the company , but never worked for it directly

also
He is President of Communications Consulting Corpor
ation; Chairman of Synergy Microwave
Corp., Paterson, New Jersey; and a partner of Rohde
 Schwarz, Munich, Germany. Previously, he was
the President of Compact Software, Inc.,


On 7/25/2014 6:50 PM, paul swed wrote:

Wow there is a tidbit I did not know Ulrich owns Synergy. I knew he was
part of Rohde  Schwartz and I firmly believe that I actually spoke with
him on 2 meters when I lived in CT on the way to work one day. A 2 meter
opening.

OK the total beg right now. Schematics for the FLL board (Not a typo) of
the SMIQ rf generator.
OK that was very on time-nuts. I apologize to the group.
However it is impressive that they did give you the support. Much as others
had in the past.
Regards
Paul
WB8TSL/1


On Fri, Jul 25, 2014 at 8:51 PM, Alexander Pummer alex...@ieee.org wrote:



Synergy's owner Ulrich Rohde N1UL --DJ2LR/DL1R is a long time ham radio
operator, and he will go pretty far to help for an other ham,
73
KJ6UHN ex DL...
Alex


On 7/25/2014 5:27 PM, Bob Stewart wrote:


And while this subject is still up, I want to let the group know that
Synergy *really* went out of their way to help me with this.  I was a bit
surprised at their level of commitment to some ham radio operator who had
bought a single unit from them and probably didn't know what the heck he
was talking about.  A real class act all around!

Bob - AE6RV




   From: Art Sepin a...@synergy-gps.com
To: Bob Stewart b...@evoria.net; Discussion of precise time and
frequency measurement time-nuts@febo.com
Cc: Tom Van Baak t...@leapsecond.com; Dusty Morris doxielove...@cox.net
Sent: Friday, July 25, 2014 5:17 PM
Subject: RE: [time-nuts] Synergy-GPS SSR-6tru Problem Resolved

Bob,

Once in a while a mea culpa is required and we're posting it here so
everyone understands our commitment to the users of Synergy's products.

The Original Synergy Adaptor Board was designed to allow Motorola's newer
3 volt 12 channel M12+ to plug into an older 5 volt 8 channel UT+ slot.
That product worked for hundreds of users over the years until (we found
out through your personal aggravation and agony) the recent introduction of
Synergy's SSR series of u-Blox based precision timing boards.

To make sure that the Synergy UT+ Adaptor Board issue is put to bed
properly we asked for an external, formal technical review of this product
that was introduced fourteen years ago.

The reviewing engineer's first comments were Ouch! This will not work.
  And, no, the SSR boards do not work the same as the M12 boards on the
Synergy Adaptor Board. The M12+ and M12M receivers have separate serial
ports for the two functions (Receiver command RxD and DGPS RxD input) so it
does not matter what you do with the RTCM port, pin 5 on UT+ connector and
pin 8 on the M12+/M12M connector, if not in use with an M12x receiver.

The SSR boards, however, had to combine the two serial data streams
expected by the M12x navigation receivers into one because the u-Blox
receiver modules only use one serial input port for both receiver commands
and DGPS correction data. The Synergy Adaptor Boards use a simple gate
combiner circuit that worked well when using the M12+ or M12M but left
Synergy open to this problem when using an SSR. Both serial lines on the
SSR board, pins 2 (Receiver RxD) and 8 (DGPS RxD) are pulled high on the
SSR board so open pins are OK but they must not be grounded.

The solution is for Synergy to make a UT+ Adaptor Board part number
available to users who only want to test the features of SSR timing
receivers.

That new SSR only Adaptor Board part number, which we'll have available
in a few days, will remove R3 (4.7K) and R4 (6.8K) from the adapter board
and the compatibility issue will be resolved. In the interim, other users
can pull pin 5 of the UT+ connector high (+5V) as you did.

We apologize for the confusion and frustration, Bob, and thank you for
the valuable feedback!

Art Sepin
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Re: [time-nuts] GPS III

[Alexander Pummer]

I received a little package with a GPS receiver + antenna from Gentleman 
[H6m] and I would like to tel him thank you very much

73
KJ6UHN
Alex


On 7/24/2014 5:57 PM, Bob Camp wrote:

Hi

If you go looking for them on the auction sites, the RYN25DI from Reyax is the 
search item for the RS-232 version. The RYN25AI is the search item for the not 
RS-232 version.

Bob

On Jul 24, 2014, at 7:15 PM, Mark Sims hol...@hotmail.com wrote:


I have purchased about a dozen of these receivers (mostly the RS-232 version 
for $1 more).   Reyax ships very fast.  I get them in about 1 week.
They work well,  and are based upon the Ublox MAX-7C.  They output independent 
GPS and Glonass NMEA messages and don't appear to merge the two systems in 
their navigation solutions.  I have not done any testing of the 1PPS signal 
(which is brought out to the connector).
--
On eBay the RNY25A1 receiver module sells for $15   

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Re: [time-nuts] new clock

[Alexander Pummer]

it does need a different design, but a buried oscillator, 5 to 8 meter 
deep in the garden has the best temperature stabilization, just don't 
turn thee power off, but that could be done using the old Greek 
water-clock principle, the spill over stabilizer. In the Bay Area 
[California] the soil's temperature is around the year approximately 
17C° ±0.01C° if you go further down it will be even more constant, 
without any heating power and control loop

73
KJ6UHN
Alex
On 7/22/2014 6:43 PM, Bob Camp wrote:

Hi

A lot depends on the oscillator. My fine old GR rack mount took most of 9 
months to settle most of the way. It was still dropping in a year after that 
when I stopped watching it. Some of my T-Bolts took a week, some took a couple 
months….

Best thing you can do with any OCXO is just leave it on power.

Bob

On Jul 22, 2014, at 7:53 PM, paul swed paulsw...@gmail.com wrote:


Agree with Marks comments.
Regards
Paul


On Tue, Jul 22, 2014 at 5:25 PM, Mark Sims hol...@hotmail.com wrote:


An oscillator can take many weeks to settle in after being powered off /
shipped / abused / looked at cross-eyed / etc.   It typically takes a
Thunderbolt a month or two to  settle down after being shipped from China.
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Re: [time-nuts] temperature sensor

[Alexander Pummer]

NTC are not that very stable, they are amorphous material winch could 
recrystallize slowly and therefore change it's electrical behavior , 
PT100 style is more reliable since it is pure metal

73
Alex

On 7/21/2014 1:22 AM, Attila Kinali wrote:

On Sun, 20 Jul 2014 23:18:38 -0700
Tom Van Baak t...@leapsecond.com wrote:


To satisfy my curiosity and get actual data I'd like to place 6 or more
tiny analog high-resolution temperature sensors all around the OCXO of a
Trimble Thunderbolt. That's high-resolution both in temperature and in time.
In other words, no fake accuracy averaging allowed. The goal is to observe
thermal gradients in real-time and see how good, or how bad, the correlation
is among crystal temperature, case temperature, and DS1620 temperature
sensor (which is mounted a considerable distance from the OCXO). The same
technique, and maybe even the same conclusions, might apply to Rb.

May i ask what speaks about using PT100/PT1000 or NTCs?

NTCs are dirt cheap, but might need some calibration first, to
get to time-nuts standards. But PT100 aren't that much more expensive
either.

eg:
The NTCALUG03 by Vishay don't look too bad, or if you want PT100
the M310 by Heraeus. The KN1510 by Heraeus look also nice, but are
a tad bit more expensive (about 20USD/pcs)


Attila Kinali



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Re: [time-nuts] Noise and non-linear behaviour of ferrite transformers

[Alexander Pummer]

No, the current passing the outside f the shield  will not induce any 
voltage inside of the coax, but the voltage drop caused by the current 
on the ohmic resistance [!!!] of the shield will show upbetween the two 
ends of the cable -- and that will  show up as  it was added to to the 
voltage which is carried on the center conductor of the coax.

73
Alex

On 7/20/2014 6:10 PM, Chuck Harris wrote:

I'm not sure what you are saying.

skin depth = (2.6/sqrt(fhz))inches for copper.

So, at 60Hz,   skin depth = 0.336 inches.
and at 100KHz, skin depth = 0.008 inches.
and at 1MHz,   skin depth = 0.0026 inches.

Are you saying that at 60Hz, because the
skin depth is deeper than the coax shield is
thick, that current passing through the outside
of the shield will induce voltage inside of
the shield, and that at say, 100KHz where the
skin depth is a little less than the shield
thickness, or at 1 MHz, where the skin depth
is only a small fraction of the thickness of
the shield that it won't?

Or something else?

-Chuck Harris

Bob Camp wrote:

Hi

The “coax is an antenna” problem comes in well before you get to DC. 
Even with no
transformer involved, the skin depth of the coax shield gives up well 
above 60 Hz
(and likely well above 100 KHz). If you want to do full isolation 
over a very wide

range you need some combination of shielding and balanced lines.

Bob

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Re: [time-nuts] quartz oscillator injection locking

[Alexander Pummer]

if you have enough buffering -- look for now noise amplifiers, which 
have low h12 [=  backward gain  ] a quartz oscillator will not lock so 
easy



On 7/19/2014 5:24 PM, Attila Kinali wrote:

On Sat, 19 Jul 2014 16:45:14 -0400
paul swed paulsw...@gmail.com wrote:


Attilla I did look at some of the documents. But none showed practical HF
class injection locking. Say as an example a 6 MHz xtal to a 1 or 2 MHz
reference.
It maybe as easy as a single transistor in the oscillators ground lead.
Always on till a brief pulse from the 1 or 2 MHz ref cuts it off. I think I
just talked myself into an attempt.

Yes, most of the papers in this area are quite theoretic. So far i've
not found anything applicable to time-nuts kind of use. Those papers
that deal with real world injection locking are mostly for integrated
circuits (90° phase shifter, frequency doubler or divider) and thus
are quite specific to the environments there.

I have not gone trough the math in detail and calculated what would
would come out in a injection locked quartz crystal. Maybe i should sit
down and do the math...

Attila Kinali


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Re: [time-nuts] sine to square wave converter

[Alexander Pummer]

look Charles Wenzel's waveform conversion: 
http://www.wenzel.com/documents/waveform.html

73
Alex

On 7/10/2014 11:40 AM, br...@ko4bb.com wrote:

On July 10, 2014 at 10:55 AM ewkeh...@aol.com wrote:


As part of the FE 405 B project a separate output circuit is in the works.
The universal controller and auxiliary board are the same as used in the
FE5680A GPSDO but because of the very low ADEV a separate circuit board that
divides by three and has also two ground isolated transformer outputs is in
the works.The question is what is the best sine to square wave converter
with the lowest ADEV contribution. I am looking at Bruce's circuit using the
ADCMP600. Any other ideas?
Thanks Bert Kehren
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Although  CERN likes that circuit for its ruggedness and versatility its a
little noisier than some alternative circuits.

Currently Linear Technology's sine to square wave devices with selectable
filtering (LTC6957 series) are better in that they are a closer approximation to
the ideal zero crossing detector.
Failing that the next best is perhaps an AC coupled  (both at input and between
emitters) differential pair of 2N3906's or similar.

Bruce
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Re: [time-nuts] Interesting frequency standard project

[Alexander Pummer]

there was an article in the January 2012issue of the elektor DCF77 
locked reference, the DCF77 has very similar modulation format as the 
new modultion format of the WWVB

73
KJ6UHN Alex

On 7/4/2014 2:21 PM, paul swed wrote:

An interesting article much like one Bert sent me circa 1989 quite recently.
The key to these systems is that the transmitters have very good references.
In the US at least we have no requirement for that level of stability on
the MW broadcasts. Though evidently some stations are quite good. I think I
have a list some place have to re-look.
Curious can you see a schematic or must you subscribe...
It is a nicely written article. I used to buy elctor in the book stores
when it was available.
Thanks
Paul
WB8TSL


On Fri, Jul 4, 2014 at 8:11 AM, Collins, Graham coll...@navcanada.ca
wrote:


I am sure there are others on list who follow Elektor Magazine and even
perhaps their forums but there are likely many that do not.

I stumbled across this interesting frequency standard project and thought
others might also be interested:


http://www.elektor-labs.com/project/low-cost-frequency-standard-disciplined-by-france-inter.14000.html

A bit of light reading and nothing really new to the old hands but it
seems that person is well on the way to being a time / frequency nut if not
already there.


Cheers, Graham ve3gtc



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Re: [time-nuts] Interesting frequency standard project

[Alexander Pummer]

for an AM station is strait forward at first use a narrow filter to make 
sure that you have just one station and feed the filter out put into a 
limiter the output of the limiter will be the carrier.

73
KJ6UHN Alex

On 7/4/2014 3:27 PM, Hal Murray wrote:

paulsw...@gmail.com said:

The key to these systems is that the transmitters have very good references.
In the US at least we have no requirement for that level of stability on the
MW broadcasts. Though evidently some stations are quite good. I think I have
a list some place have to re-look.

How stable are they?  Could they provide a good regional reference if
somebody with a good setup would measure several stations and publish the
results?  How often would you have to measure?

How do you measure the frequency of an AM or FM station?  Wait for silence
and process it like CW?

Any suggestions for a receiver (or whatever) that would be appropriate for
that sort of project?  I assume the main requirements are an external freq in
and a serial/USB port to adjust the knobs.

--

Ages ago, I remember seeing a small booklet (20 pages?) from NBS describing
their setup with HP that was using NBC's atomic clock for time distribution.
HP's part was to run the west coast calibration to get the delay over phone
lines from the east coast to the west coast.  Has anybody seen a copy of that
booklet online?




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Re: [time-nuts] DIY FE-5680A lobotomy (disable temp compensation)

[Alexander Pummer]

keep the heat sensing very close to the heating to avoid thermal control 
oscillation ! a thermal time constant is large and no to easy to deal 
with it

73
Alex

On 7/3/2014 6:35 PM, Angus wrote:

Hi Bert,

I am thinking about testing a heat pipe on a fan cooled setup I use.
The first temp controlled chassis I did used a peltier and works very
well, but was a lot more work to do and is much more power hungry.

The main problem I find is not the temp controller itself, but rather
the change in the temperature across the chassis as the ambient
changes. However good the temp controller is, it only controls a
single point, but other points further away from the sensing
thermistor can vary a lot.
I noticed you posted a picture of a heat pipe cooler a couple of weeks
ago - did you happen to compare the temperature across the unit with
direct fan cooling and the heat pipe cooler, or with different heat
pipes?

Angus.



On Sat, 28 Jun 2014 12:37:37 -0400 (EDT), you wrote:


Will someone beside us use heat pipe. Would love to have an impendent
input. What does it take to get a test going. Scott has done a lot of work, how
about some one else step up to the plate. There are a lot of time nuts out
there  with the 5680A,many for the first time will have a very good
reference and some  of our experts with proper equipment can make a big 
difference.
Bert Kehren


In a message dated 6/28/2014 12:20:12 P.M. Eastern Daylight Time,
newell+timen...@n5tnl.com writes:

At 04:32  AM 6/28/2014, wb6bnq wrote:


monitoring process ?  In other  words have you traced out the
connections to see what is driving the  pin you think is the temperature

input ?

No. I've only traced back from  the ADC input to the voltage divider.



The next big question is  have you monitored the frequency and its
stability, externally, to  observe what effects are taking place when
you disable this input to  the A/D ?

I have not.



That sounds complicated and messy  but may be easier than it
appears.  An appropriate container  would be:

It does sound messy. I don't think I'm willing to dunk one of  my units.

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