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

[Alex Pummer]

most likely the cooper is much ticker than the penetration of the lowest 
frequency for which the cable is used, therefore the high frequency 
"does not" see the steel inside of the cooper, that steel could cause 
problem if the coax also used to carry some power -- DC or AC -- because 
at lower frequency or DC the cable's current carried mostly in the 
cooper, and while the cooper constitute just a small fraction of the 
center wire cross section, a cable with "steel core" could carry much 
less current, than a cable with full cooper. But the steel core cable 
has one advantage it is usually stronger than a full cooper cable and 
therefore it is usable for outside installation with larger support 
distance.


73
KJ6UHN,  [a former engineer of a cable manufacturer ]
Alex

On 4/19/2017 11:57 AM, Hal Murray wrote:

kb...@n1k.org said:

I’d want to be pretty sure what the center conductor was made out of. I’ve
seen some stuff in coax that “one would think� should not be there (copper
over steel …).

Does that effect the propagation time?

If I gave you a good scope picture of a pulse after going through chunk of
coax, could you figure out the ratio of copper to steel?  Would you need to
know the length or could you figure that out too?



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Re: [time-nuts] Re. DIY atomic "resonator" 6GHz synthesizer from ADI

[Alex Pummer]

the are 6GHc synthesizer chips from ADI available see here 
http://www.analog.com/en/analog-dialogue/articles/design-a-direct-6-ghz-local-oscillator.html


73

KJ6UHN

Alex


On 4/11/2017 8:29 AM, Attila Kinali wrote:

On Tue, 11 Apr 2017 07:31:01 +
Andre  wrote:


Has anyone else either built an atomic clock around a bare Rb lamp module 
"core" or attempted

to make a hydrogen maser?

Building my own Rb vapor cell standard or H-maser is on my list
of Things-I-have-to-do-before-I-die :-)

If I had to do one of those now, I would go for a Rb vapor cell
with dual-resonance using an external cavity laser diode for pumping.

The electronics for such a thing are relatively easy, if you are not
afraid of Jiga-Hurts and using these pesky QFN packages. But it isn't
cheap either. There was a discussion started by Bert[1] where I ventured
a rough calculation what I think it wold cost. Though I think I have
understimated the cost of an ECLD (it's more like 1k-5k from what I have read)


Attila Kinali

[1] search for "thinking outside the box" in the archives



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Re: [time-nuts] Re. DIY atomic "resonator"-- replacing SDRs

[Alex Pummer]

YES SDRs [step Recovery Diodes] is hard to find today, but there many-- 
PIN -- diodes, which exhibits that effect, even some standard rectifier 
diodes could be used for, despite of that Magnus is right, today are 
better solutions available e.g. PLLs with 10GHz prescalers


73

KJ6UHN

Alex


On 4/11/2017 9:22 AM, Magnus Danielson wrote:



On 04/11/2017 05:54 PM, Richard (Rick) Karlquist wrote:



On 4/11/2017 12:31 AM, Andre wrote:


Has anyone else either built an atomic clock around a bare Rb lamp
module "core" or attempted



Not a DIY project, but I was the RF designer on the HP 10816 rubidium
standard, which never made it to product introduction (a half dozen
working pilot run units were built in 1982).  I would say this task is
probably beyond the scope of a DIY project, at least for most
time-nuts.


Probably right.


The Rb lamp drive circuit (particularly getting the
lamp to light up) is very challenging.


There would be none. It would be replaced by a laser. That has its own 
set of "problems" but different.



The step recovery diode multiplier is very challenging.


Today you would not go the SRD route in synthesis.
Besides, SRDs can be hard to find these days.


The photodetector and loop integrator is non trivial.


I'd expect the loop integrator to be done in digital, which eases up 
on some of the design problems.



The synthesizer is the one thing that is easy in 2017.


Indeed-

> The oven is also no simple thing to get

low tempco.  Unlike a crystal, you have a lot of heat being
generated by the lamp, etc. The lamp needs to be at a different
temperature than the other cells.


Going down the laser-route, the balance of temperature between the 
cells is no longer a relevant problem. Further, the lamp and its heat 
is gone.



You have to keep the tip
off at the lowest temperature to keep the Rb in place and not
"flood" the cell and block the light.  Etc., etc.


You still have this problem, but not as a lamp problem but only for 
the resonance cell part.



This is in the category of projects where if you were qualified
to do it, your time is far too valuable to do it for the amount
of money you would save.


This is the type of project you do not to save any money, but to spend 
and learn.


Even if done in a much more modern fashion, avoiding several of the 
traditional problems, there is plenty of issues to solve and handle.


Cheers,
Magnus
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Re: [time-nuts] Sinlge ADC multi-band receiver

[Alex Pummer]

depend how much in-band loss could you afford it is relative easy to 
make cavity filters if you have a network analyzer available


73

Alex


On 4/10/2017 9:11 AM, Attila Kinali wrote:

On Sun, 9 Apr 2017 18:13:48 -0400
Bob kb8tq  wrote:


The beauty of the system would be that you don't need a SAW filter
at all. If the input stage (LNA + mixer) has a high enough dynamic
range, then the (first) IF filer alone can remove all those out of
band interference.

Why would you substitute an expensive IF filter for a cheap front end filter?

Availability: Although there are L1/L2 filters available, they are not
easy to get unless you buy them in bulk. The standard L1 filters you
can buy are rather narrow band (just 2-4MHz) and don't allow the
reception of the modern signals. L5 filters are very rare and E5 filters
simply do not exist yet.

And keep in mind that the IF filter does not need to be a special
ultra-steep filter. The high sampling rate of the ADC allows to place
the input signal such, that the stop band can be quite far from the
pass band. Also, the filter is only really necessary to filter out
narrow band interference, which is hopefully far from the signal anyways.
Having a bit of noise fold in is, as Jim noted earlier, not a problem at all.

Attila Kinali


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Re: [time-nuts] Car Clock drift - the lowly 32kHz tuning fork crystal specs

[Alex Pummer]

actually it does not compensate for temperature it is just for reduce 
the production cost for the crystal. We --Jean Hoerni [founder of 
intersil, Eurosil and one of the  traitors who started Fairchild 
Semiconductor] and me -- made something very similar at the time of 
begin of the quartz clock era for Lipp a French watch maker in Bezancon 
[a city an France the spelling is most likely not correct]. The company 
exhibited it at the Basler exhibition of Horology, the clock was simple 
good working and not to expensive, Ebachos --OMEGA -- people visited the 
booth, they also had their quartz  clock which was much more expensive 
-- they looked, the Lipp clock and told na there are Rolls-Royce s and 
deux chevaux [that was a simple little ugly but very reliably French car 
] as response Mr. Hoerni told them yes, and there are technologies not 
known in your house, the Omega people recognized him and walked away 
quietly...


73

Alex


On 4/9/2017 1:11 PM, Bill Hawkins wrote:

Nice article in Wikipedia. Didn't see any familiar names in the
reference list, though.

Seems to me inhibition compensation is useful for compensating for the
variation in purchased crystal frequencies, but not for temperature
compensation.

Also seems to me that a watch spends 2/3 of a day at wrist temperature
and 1/3 at bedroom temperature, which varies with the seasons.

Would a ceramic capacitor crafted for a certain temperature coefficient
work? Can the fork have a crafted tempco?

Bill Hawkins


-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Ron
Bean
Sent: Sunday, April 09, 2017 12:05 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Car Clock drift - the lowly 32kHz tuning fork
crystal specs


In your case, the car sits in an environment that matches their test
setup well. In my case ?\200? not so much.

FWIW, mine drifts pretty badly. It's in an aftermarket stereo, and I
don't remember when I bought it (I moved it from my previous car).

I assume that all quartz clocks and watches these days use "inhibition
conpensation".

https://en.wikipedia.org/wiki/Quartz_clock#Inhibition_compensation


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Re: [time-nuts] HP-59309A Clock counts only seconds, HEF4011

[Alex Pummer]

NOt pin-compatible but functional compatible and available is the 74C00 
or74 HC00, which has a long life I am using one in my gate alarm 
since1989, it is on all the time and the chip is available the HEF4011 
is also available -- at Mouser -- it is pin-compatible and function  
with CD4011 ad it is made by Philips [NXP]


73

KJ6UHN

Alex


On 4/3/2017 4:43 PM, Jeremy Nichols wrote:
I have a new-to-me HP-59309A HP-IB Digital Clock. The clock works on 
both the internal crystal oscillator and on an external 10 MHz 
standard (GPSDO). However, it counts only to 60 seconds and then 
repeats without updating the minutes digit. The TIME SET (FAST and 
SLOW) push-buttons work but again, the count will not update minutes 
and hours, only seconds. The DAY SET procedure works correctly for 
days and months. All the other switches and buttons do what they are 
supposed to do. Using my 10526T logic pulser I can force the minutes 
and hours counters to work. The power supply is in good condition 
(after replacement of a few components) and I see no other problems 
(yet).


Tracing the clock signal through the logic circuitry brought me to U3 
on the A4 board. This (U3) is a 4011 quad 2-input NAND gate in a 
14-pin DIP package. It "connects" the seconds counter to the minutes 
counter and appears to have failed. One of the people on the email 
list  commented that the 4000 
series CMOS chips have a known limited lifetime. Since these parts are 
no longer in production, the writer expressed the concern that any 
parts I might find to buy may be DOA.


Before I go hunting for parts, I'd appreciate hearing from anyone in 
the group who has experience with the 59309A Clock and/or the 
4000-series CMOS family. In particular, are there modern equivalents 
to my 4011 chip? If the 4000's really do have a limited lifetime I'd 
rather use a substitute.


Jeremy, N6WFO


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Re: [time-nuts] TAPR TICC boxed

[Alex Pummer]

FJH1100
Ultra Low Leakage Diode

Alex


On 3/31/2017 6:00 PM, Charles Steinmetz wrote:

Mark wrote:

I thought about using the clamp diodes as protection but was a bit 
worried about power supply noise leaking through the diodes and 
adding some jitter to the input signals...


It is a definite worry even with a low-noise, 50 ohm input, and a 
potential disaster with a 1Mohm input.  Common signal diodes (1N4148, 
1N914, 1N916, 1N4448, etc.) are specified for 5-10nA of reverse 
current.  Even a low-leakage signal diode (e.g., 1N3595) typically has 
several hundred pA of leakage.  Note that the concern isn't just power 
supply noise -- the leakage current itself is quite noisy.


For low-picoamp diodes at a decent price, I use either (1) the B-C 
diode of a small-signal BJT, or (2) the gate diode of a small-geometry 
JFET. A 2N5550 makes a good high-voltage, low-leakage diode with 
leakage current of ~30pA.  Small signal HF transistors like the MPSH10 
and 2N5179 (and their SMD and PN variants) are good for ~5pA, while 
the gate diode of a PN4417A JFET (or SMD variant) has reverse leakage 
current of ~1pA (achieving this in practice requires a very clean 
board and good layout).


I posted some actual leakage test results to Didier's site, which can 
be downloaded at 
. 
 This document shows the connections I used to obtain the data.


The TICC doesn't have the resolution for it to matter or justify a 
HP5370 or better quality front end. I'll probably go with a fast 
comparator to implement the variable threshold input.


Properly applied, a fast comparator will have lower jitter than the 
rest of the errors, and is an excellent choice.  Bruce suggested the 
LTC6752, which is a great part if you need high toggle speeds (100s of 
MHz) or ultra-fast edges.  But you don't need high toggle rates and 
may not need ultra-fast edges. Repeatability and stability are more 
important than raw speed in this application.  The LT1719, LT1720, or 
TLV3501 may work just as well for your purpose, and they are 
significantly less fussy to apply.


Note that the LTC6752 series is an improved replacement for the 
ADCMP60x series, which itself is an improved replacement for the 
MAX999.  Of these three, the LTC6752 is the clear winner in my tests.  
If you do choose it (or similar), make sure you look at the 
transitions with something that will honestly show you any chatter at 
frequencies up to at least several GHz.  It only takes a little 
transition chatter to knock the potential timing resolution of the 
ultra-fast comparator way down.  Do make sure to test it with the 
slowest input edges you need it to handle.


Best regards,

Charles


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Re: [time-nuts] PLL Digital Loop Filter

[Alex Pummer]

it is tempting to use digital loop filter for PLL if a very low 
bandwidth is required, but with the large time constant is a problem ; 
the VCO will change it's frequency despite the tuning voltage remains 
constant and that is not so simple to model.


73

KJ6UHN

Alex


On 3/21/2017 4:39 AM, Attila Kinali wrote:

On Mon, 20 Mar 2017 21:32:28 -0700
James Peroulas  wrote:


I'm trying to understand how to design and analyze the loop filters in a
digital PLL. Specifically, because of digital processing delays, the phase
offset measured at time t will only produce a change on the VCXO input at
time t+T, where T is the sampling period of the digital loop.

You have the same delays in analog filters as well. As a rule of thumb
you can assume that the delays are in the same order of magnitude as
with the equivalent analog filters, not accounting for the delays due to
pre- and post-processing of the signal.
  
The analysis of digital PLLs works the same as with analog ones, you

just exchange the Laplace transform with the Z-transform. You can add
arbitrary delays due to pre/post-processing as a simple multiplication
by 1/z for each clock cycle of delay.


I've found plenty of texts describing analog loop filters. Are there any
recommendations for digital loop filter PLL design?

The PLL book by Best contains two chapters on how to design digital PLLs.
I can also recommend "Understanding digital signal processing" by Lyons,
which is a very hands-on description how to do filters and perform other
signal processing tasks.


Attila Kinali



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Re: [time-nuts] Antique precision timing device without, > electronics

[Alex Pummer]

Professor Dr. Rohde of Rohde %Schwarz designed in the 1940-es one tuning 
fork oscillator for 400Hz which was to one crystal phase locked. The 
company built many exemplars from it.  I have seen one working unit in 1967.


73

KJ6UHN


On 3/17/2017 1:14 PM, Dan Kemppainen wrote:

This is all cool stuff, and neat to read about.

What's the best (Most stable, most accurate, best adev, etc.) tuning 
fork oscillator made?


What the lowest frequency tuning fork oscillator ever built? Was 1Hz 
ever achieved commercially?


Fun stuff for Friday!

Dan



On 3/17/2017 12:00 PM, time-nuts-requ...@febo.com wrote:

Message: 8
Date: Fri, 17 Mar 2017 01:34:39 +0100 (CET)
From: "iov...@inwind.it" 
To: Discussion of precise time and frequency measurement

Subject: Re: [time-nuts] Antique precision timing device without
electronics
Message-ID:
<1660573894.5853221489710879161.javamail.ht...@webmail-13.iol.local>
Content-Type: text/plain;charset="UTF-8"

This is mine, used to calibrate some aircraft related equipment:

https://www.flickr.com/photos/103726899@N08/33326340242/in/dateposted-public/ 



and its diagram:

https://www.flickr.com/photos/103726899@N08/33482556075/in/dateposted-public/ 



iov

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Re: [time-nuts] Bye-Bye Crystals

[Alex 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

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

[Alex Pummer]

just be careful, because if you under-heat the cathode you could kill it

73

Alex


On 2/13/2017 7:11 PM, Bob Camp wrote:

Hi



On Feb 13, 2017, at 8:15 PM, Scott Stobbe  wrote:

On Mon, Feb 13, 2017 at 6:41 PM, Bob Camp  wrote:



I think what you would find is that it *is* a fairly normal AT cut and the
data book
that came with the instrument plotted out the data for the specific
crystal in
the device. The usable temperature range was fairly small, so the plot will
be pretty linear.


Attached is a plot of crystal calibrators temperature stability. Span is
roughly 65 degC.

Which eyeballs out to be pretty close to an AT. Without knowing the PPM
scale there isn’t much way to be sure.


One of the other aspects I think is intriguing is the DC PSRR of a vacuum
tube crystal oscillator. In the case of a bjt based oscillator you have the
C-V relation for depletion capacitance and the base-emitter dynamic
capacitance as a function of collector current. I would suspect that for a
one active device oscillator, tube vs bjt, a tube crystal oscillator would
be less sensitive to small power supply variations (+- 10% ).

Except you *do* have miller effect which pretty much messes things up
for a triode. A pentode is a bit less sensitive, but you still have issues.


Which is a
convenient attribute for a poorly/unregulated battery supply in the vacuum
tube case. Unless filament current has an appreciable impact on frequency,
I wouldn't think so…

Umm… e …. check it out :)
Oddly enough, I remember a high school physics lab where they had us plot
the effect of filament voltage on plate current and gain. Seemed like a weird
thing to do to me at the time. Turns out the teacher grew up with microwave 
tubes
that were tuned by varying the filament. Who knew ???  Pretty strange stuff if
you ask me.

The bigger issue is the tubes get hot. The heat varies with supply voltage.
Temperature change is the result. That temperature change messes up
oscillator stability. You pretty much have to wait for things to hit equilibrium
before you do useful stuff ( = let it warm up for an hour or four).

Bob




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Re: [time-nuts] What to do with a 5061A/5061B with dead NiCds

[Alex Pummer]

it is a "ventilated flooded" battery?

73

if it s a flooded battery it is very easy to fix it


On 2/5/2017 3:27 PM, Skip Withrow wrote:

Hello time-nuts,

I have 5061A and 5061B units with the battery option and dead battery
packs.  My question is what makes the most sense when refurbing these units?

1.  Yank the old battery out and just leave it that way.  Running the unit
on a UPS would preserve the functionality.

2. Replace the pack with a rebuilt NiCd pack.  I'm sure Batteries Plus
would be happy to do it, but sounds expensive.

3. Replace the pack with a NiMH pack, and really crank down the float
current of the 5061.

4. Replace the pack with Li-ion battery.  Would be a much smaller battery,
but the charging circuit would have to be pitched.  Building in a Li-ion
charge controller sounds like it could be a project (which I don't
necessarily want).

5. Yank the old battery pack and run the 5061 on two 12V batteries with an
appropriate power supply/charger (basically a version of #1).

Any thoughts on these or other options would be appreciated.  Thanks in
advance.

Regards,
Skip Withrow
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Re: [time-nuts] 10MHz to 25MHz

[Alex Pummer]

once upon the time there was an other crystal material -- NOT quartz ! 
--  the Russian came up with it, perhaps Bernd [Neubig] remembers on 
that, what happened to that story?
that crystal could be run at higher drive level, therefore it would be 
possible to make some better oscillators

73
KJ6UHN
Alex



On 1/20/2017 8:38 AM, Bob Camp wrote:

Hi

If you think about it, current through the crystal is at least as important as
“drive level”. They are related by the crystal resistance. As the overtone
goes up, the resistance (in general) goes up. There are size constrained
designs where other things get in the way of this. There are also tricks
that might be used to degrade the fundamental.

Since the resistance is higher at the 5th than at the fundamental, 1 mw of 
crystal
dissipation (drive level) is going to be less current through the crystal. At 
some
(possibly a bit removed) point that gets you less current into your buffer 
amplifier at
a given impedance level. Less current / same impedance gets you to worse signal
to noise broadband.

Is this really that big a deal? As always … that depends. ADEV usually degrades
as drive goes up. Phase noise gets better. At some point this or that crystal 
explodes
(the electrodes fly off). It is uncommon to get to the damage level on a 
crystal. You
normally massage the design in the tradeoff region.

Bob


On Jan 19, 2017, at 7:31 PM, Scott Stobbe  wrote:

Is there any reason why you wouldn't be able to run the same drive level on
say the fifth overtone versus the fundamental? I would guess at 100 MHz it
may be 3rd or 5th, or are they fundamental?

The comments one drivelevel are simply based on snr, larger signal with
same noise, better snr

On Thu, Jan 19, 2017 at 7:06 PM Bob Camp  wrote:


Hi






On Jan 19, 2017, at 3:03 PM, Scott Stobbe 

wrote:


Wouldn't crystal drive level be one of the important specifications for

far


out phase noise?



It would, but you can get the same floor at 10 MHz as you can get at 100
MHz.



Bob




On Thu, Jan 19, 2017 at 1:33 PM, Bob Camp  wrote:

HI
A lot of your evaluation of the term “better” will depend on your

intended


use. One of the limits on phase noise
is the thermal noise floor. Because of that, starting at a higher
frequency will always give you an edge on broadband
phase noise. ADEV / short term stability is linked to the Q of your
resonator. In a quartz crystal, maximum Q is
roughly proportional to frequency. The other limit on Q is blank

geometry


(size). One other limit is practicality -
is a $250,000 OCXO that is 1 cubic meter in size appropriate for your
application? The answer to that one is
universally - NO :) Somewhere along the line of larger size and cost,
other technologies make more sense.
So, if better = phase noise floor, 100 MHz is better than 10 MHz. If
better = ADEV, 5 MHz in a large package is
likely better than 100 MHz. Indeed these are only two variables. There

are


*many* others you could look at.
Lots of fun
Bob

On Jan 19, 2017, at 7:13 AM, Charles Steinmetz 

wrote:

Chris wrote:

I have always wondered why we build our "standard" with such a low
frequency.   Why not a 100MHz GPSDO?   Why 10MHz

Quartz crystals work better at lower frequencies, predominantly because

they have higher Q.  10MHz was chosen because it is low enough for
excellent performance but high enough to be directly useful (since an
accident of biology gave us ten fingers, we've created a base-10 world

and


powers of 10 are favored in almost everything).

In prior times, 5MHz crystals held this position, and before that,

1MHz.  There is a good argument even today that the best 2.5MHz or 5MHz
crystals are better than the best 10MHz crystals, but not by enough to

make


2.5MHz or 5MHz standards popular any longer.

One lonely data point, which proves nothing:  My best crystal

oscillator


is a Symmetricom clone of the double-oven HP 10811s (it came out of an

HP


GPSDO, so apparently HP at one time used them interchangeably with the
10811).  That OCXO uses a 5MHz crystal and a frequency doubler to

produce


its 10MHz output.

Best Regards,
Charles

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Re: [time-nuts] Brass screws

[Alex Pummer]

Titanium, it is expensive but strong and non magnetic at all

73

KJ6UHN

Alex


On 1/17/2017 9:40 AM, Hal Murray wrote:

jebponso...@gmail.com said:

Though nominally made of copper and zinc, common brass often shows residual
ferro magnetism because it is "recovered" metal and is  contaminated with
iron. That brass must never be used in a magnetic instrument have been known
for a very long time.

What do people use?




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Re: [time-nuts] Nutty time-nuttery with WWVB

[Alex Pummer]

basically one could make a very good 60kHz clock distributor system, by 
running a large loop around the property, -- as long as the loop's 
length is much less than the wave length the current will be constant 
along the loop -- that way  you will have reception inside the loop with 
vertical magnetic, and very weak reception outside of the loop. At the 
clocks you need to turn the antenna from horizontal to vertical, and you 
could use such low power a few mW, that the FCC would not worry about 
it, similar system is used as invisible fence for dogs, but for the 
clock one need much less power, since the clocks have a very sensitive 
receiver unlike the "dogs receiver".


73
KJ6UHN
Alex
alias Dr.Alexander Pummer,
PCS Consultants
Pleasanton

On 11/10/2016 10:45 AM, Van Horn, David wrote:

I have, for many years, wished the FCC would get serious on enforcement.
I've dealt with CEOs who said basically "ok, so it's illegal, who's going to catch 
us?"
I have on occasion had to physically stop shipments from being made.

If we had enforcement with TEETH then it would be easy to make the case to 
management that they stand a good chance of getting spanked in the wallet.
That's the only place a corporation has pain receptors.
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Re: [time-nuts] Nutty time-nuttery with WWVB

[Alex Pummer]

Well, there is such zoo, that nobody could find what coming from where, 
I tried with an R EMI receiver and antennas, but on the other hand one 
could use the high level of energy to supply the power for small 
circuits


73
KJ6UHN
Alex

On 11/10/2016 10:15 AM, Clint Jay wrote:

Don't forget power line networking equipment but just because one
interference source is tolerated or in order by the authorities doesn't
mean it's ok to create another.

Those switchers and even the hardware they power (I'm thinking of satellite
receivers which spew all sorts of hash over HF bands)  are terrible sources
of unmonitored QRM.

On 10 Nov 2016 17:46, "Alex Pummer" <a...@pcscons.com> wrote:


And how about that many, many "radiator" which are moving up and down with
their carriers and don't give a damn about FCC Part 15 and radiating
radiating day and night with substantial power, I meant that FFC approved
and not approved switching mode power supplies, of which every household
has a hand full of it?

73
KJ6UHN
Alex

On 11/10/2016 9:22 AM, William H. Fite wrote:


I heartily second Charles' admonition regarding FCC PART 15 unlicensed
transmissions. Part 15 explicitly states that an unlicensed operator may
not cause interference with any licensed transmission. Because of the
specific purpose of WWV/WWVB transmissions, any discernible leakage
detectable by any other user is prima facie evidence of unlawful
transmission and subject to a heavy fine. I assure you that any licensed
Part 97 user who detects your emissions over the top of WWVB is quite
likely to rat you out to Uncle Charlie. And should, may I say, because you
will be interfering with a public service. "I am just syncing my clocks"
is
not going to impress the guys who appear in your driveway in a white van
with RDF antennas on the roof.

Sobe very damned sure that you are not radiating a discernible signal
outside of the immediate vicinity of your clocks.

Bill
KJ4SLP



On Thursday, November 10, 2016, Charles Steinmetz <csteinm...@yandex.com>
wrote:

Peter wrote:

Could I implement my own personal WWVB transmitter that would


be powerful enough to be picked up by the clocks in my house?
   *   *   *
Has anyone tried this?

Some on the list have, and I'm sure they will provide the details.

Others have mentioned the potential problems with interference to other
WWVB users.  For starters, make sure you study and understand Part 15 of
the FCC rules before you put it on the air, or you could face a nasty
enforcement action.  (Even if you are Part 15-compliant, you may still
screw up other users' reception and get a visit from the FCC when they
complain.  I operate several very sensitive 60kHz receivers -- if you
live
in my neighborhood, I'm almost certain to be unhappy about anything you
deploy.)

Note that the problem with most "atomic" clocks that I've seen is
actually
not insufficient signal (in the wee hours of the morning, when they try
to
synch).  It is either excessive QRM, or orienting the clock so its
antenna
has a null toward Fort Collins.  Make sure the antenna has a major lobe
toward Fort Collins (this may require relocating the entire clock or
bringing the antenna out so you can orient it independently), and that it
is well clear of the AC mains distribution wiring in your house and any
other sources of QRM (wall warts, CFL lamps, LED lamps, etc. (this may
also
require relocating the clock).

The typical clock using a loopstick antenna has lobes to the front and
rear, and nulls to the sides.  Thus, mounting the clock on the western
exterior wall (for users on the east coast) is usually best.  Putting it
directly in front of a west-facing window may help.

Best regards,

Charles


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Re: [time-nuts] Nutty time-nuttery with WWVB

[Alex Pummer]

And how about that many, many "radiator" which are moving up and down 
with their carriers and don't give a damn about FCC Part 15 and 
radiating radiating day and night with substantial power, I meant that 
FFC approved and not approved switching mode power supplies, of which 
every household has a hand full of it?


73
KJ6UHN
Alex

On 11/10/2016 9:22 AM, William H. Fite wrote:

I heartily second Charles' admonition regarding FCC PART 15 unlicensed
transmissions. Part 15 explicitly states that an unlicensed operator may
not cause interference with any licensed transmission. Because of the
specific purpose of WWV/WWVB transmissions, any discernible leakage
detectable by any other user is prima facie evidence of unlawful
transmission and subject to a heavy fine. I assure you that any licensed
Part 97 user who detects your emissions over the top of WWVB is quite
likely to rat you out to Uncle Charlie. And should, may I say, because you
will be interfering with a public service. "I am just syncing my clocks" is
not going to impress the guys who appear in your driveway in a white van
with RDF antennas on the roof.

Sobe very damned sure that you are not radiating a discernible signal
outside of the immediate vicinity of your clocks.

Bill
KJ4SLP



On Thursday, November 10, 2016, Charles Steinmetz 
wrote:


Peter wrote:

Could I implement my own personal WWVB transmitter that would

be powerful enough to be picked up by the clocks in my house?
  *   *   *
Has anyone tried this?


Some on the list have, and I'm sure they will provide the details.

Others have mentioned the potential problems with interference to other
WWVB users.  For starters, make sure you study and understand Part 15 of
the FCC rules before you put it on the air, or you could face a nasty
enforcement action.  (Even if you are Part 15-compliant, you may still
screw up other users' reception and get a visit from the FCC when they
complain.  I operate several very sensitive 60kHz receivers -- if you live
in my neighborhood, I'm almost certain to be unhappy about anything you
deploy.)

Note that the problem with most "atomic" clocks that I've seen is actually
not insufficient signal (in the wee hours of the morning, when they try to
synch).  It is either excessive QRM, or orienting the clock so its antenna
has a null toward Fort Collins.  Make sure the antenna has a major lobe
toward Fort Collins (this may require relocating the entire clock or
bringing the antenna out so you can orient it independently), and that it
is well clear of the AC mains distribution wiring in your house and any
other sources of QRM (wall warts, CFL lamps, LED lamps, etc. (this may also
require relocating the clock).

The typical clock using a loopstick antenna has lobes to the front and
rear, and nulls to the sides.  Thus, mounting the clock on the western
exterior wall (for users on the east coast) is usually best.  Putting it
directly in front of a west-facing window may help.

Best regards,

Charles


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Re: [time-nuts] Nutty time-nuttery with WWVB

[Alex Pummer]

see here: 
http://ka7oei.blogspot.com/2013/03/getting-atomic-wwvb-clocks-to-work.html


73
KJ6UHN
Alex

On 11/10/2016 4:18 AM, Peter Reilley wrote:

I have a few of those "atomic" clocks that receive WWVB to set the time.
However since I live on the east coast they may only pick up the signal
once or twice per year.

Could I implement my own personal WWVB transmitter that would
be powerful enough to be picked up by the clocks in my house?
The signal at 60 KHz might be able to be produced directly by some
sound cards.   With that and a ferrite rod antenna I might get
reliable time elsewhere in my house outside of my lab.

Has anyone tried this?

Pete.

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Re: [time-nuts] Sapphire oscillators

[Alex Pummer]

there was another sapphire oscillator company:

Industry News 
/ Test and 
Measurement Channel 




 A Mobile Ultra-low Phase Noise Sapphire Oscillator


   Introduction to a low noise fixed-frequency X-band sapphire
   cavity oscillator

Poseidon Scientific Instruments Pty Ltd.

Fremantle WA  near Perth
January 1, 2002

http://www.microwavejournal.com/articles/3367-a-mobile-ultra-low-phase-noise-sapphire-oscillator

They were acquired, the produced shoe-box size  oscillators ready for 
industrial/military application ...A self-confessed alternative guy from 
Fremantle has sold the world-leading high technology firm he founded 24 
years ago to global defense giant Raytheon.


73

KJ6UHN

Alex


On 11/9/2016 4:48 PM, Attila Kinali wrote:

On Thu, 10 Nov 2016 11:20:37 +1100
Jim Palfreyman  wrote:


Anyone got any comments on this?

http://www.theleadsouthaustralia.com.au/industries/technology/worlds-most-precise-clock-set-for-commercial-countdown/

Cryogenic sapphire or whispering gallery mode oscillators have been around
for quite some time. You basically have a piece of sapphire (aluminium oxide
in crystaline form)[1] in a cavity[2,3], cool everything down to liquid
helium temperatures and use this as an oscillator. There are two popular
configurations, one is to use the sapphire as resonant element like in
an LC or crystal oscillator, or more commonly, to use the sapphire as a
filter element in Pound locking scheme[4].

The short term stability of these oscillators is AFAIK unsurpassed
and flat up to 1000-10'000s, but exhibits drift at longer taus[5].

Their biggest problem is that they need a liquid helium cryo-cooler
which causes vibrations that need to be carefully filtered out.
This also makes them relatively large (fill between one and two 19" racks)


Attila Kinali

[1] http://www.uliss-st.com/uploads/pics/tech2.jpg
[2] http://inspirehep.net/record/1244235/files/cavity.png
[3] http://www.uliss-st.com/uploads/media/imgmedias.jpg
[4] That's the (original) microwave variant of the Pound-Drever-Hall
locking scheme, see 
https://en.wikipedia.org/wiki/Pound%E2%80%93Drever%E2%80%93Hall_technique
[5] http://inspirehep.net/record/1409150/plots


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Re: [time-nuts] Normal operating specs of a Morion MV89?

[Alex Pummer]

Hi Brian

which cap is failing in the MV89 oxco-s?
73

KJ6UHN

Alex

On 9/20/2016 2:41 PM, Bryan _ wrote:

Any tips on resoldering the can, special solder or flux required? Quite often 
they can be found for a good price on Ebay, from what I have read they are a  
good OCXO minus the issue of the one particular cap failing.

-=Bryan=-
  

From: brayn...@gmail.com
Date: Tue, 20 Sep 2016 20:06:59 +
To: time-nuts@febo.com
Subject: Re: [time-nuts] Normal operating specs of a Morion MV89?

Yes. This low output due to capacitor failure is a very common failure.
 From the last set of MV89a I got on the bay, all had this issue.

I had good luck opening mine with a hot air rework station with a small
nozzle to blow the solder seal away. A bit of careful prying with a thin
flat screwdriver while it is still hot to pop the bottom from the case. The
capacitor is easy to get to once the outer can is removed. Hot air to
remove. Then tweezers and a fine point soldering pencil made for an easy
repair.

Obviously, be very careful and be sure to work on an appropriate surface
for the amount of heat involved.
- Brian

On Tue, Sep 20, 2016, 12:57 PM Bryan _  wrote:


May also want to check the output amplitude. If memory serves me correct
it is very common for a capacitor inside this model number to fail. It can
be fixed but requires a torch or a pretty heavy duty soldering iron to get
the can open.
http://www.rbarrios.com/projects/MV89A/

-=Bryan=-


From: lister...@gmail.com
Date: Mon, 19 Sep 2016 14:31:06 -0700
To: time-nuts@febo.com
Subject: [time-nuts] Normal operating specs of a Morion MV89?

I recently ordered and received what claims to be a 2007 vintage
Morion MV89 from ebay (I say claimed as that what the auction item
said, but my unit is missing the identifying label on the top and just
has '2007 MV89A' written on the side in marker). I've powered it up
with a bench power supply at 12V and it's drawing 390mA at steady
state. I measured the case temperature with a ThermaPen Mk4 (not often
I get to combine the hobbies of bbq and timenuts...) which is
calibrated to +/-0.7F to be about 111F, varying somewhat with
position.

This seems pretty hot - Is this normal ? The datasheet says it should
draw <350mA when at steady state but doesn't say what temp it should
be at. Does anyone else have info on their version to see whether this
is normal ?

Cheers,
Tim
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Re: [time-nuts] Optical link connects atomic clocks over 1400 km of fibre

[Alex Pummer]

to shield against DC and low frequency magnetic field usually high 
permeability magnetizable material -- Permalloy, Mu-metal or similar is 
used, the field concentrates in the high permeability material and 
"behind it" is no left over magnetic field


73

Alex


On 8/25/2016 11:10 AM, Magnus Danielson wrote:

Hi,

On 08/25/2016 11:04 AM, Bill Metzenthen wrote:

On 25/08/16 18:25, Poul-Henning Kamp wrote:


In message
<1057836989.2088307.1472104857885.javamail.ya...@mail.yahoo.com>, Br
uce Griffiths writes:


You'd need a rather thick copper jacket to shield effectively
against the 50Hz magnetic field.

As in: A good-sized fraction of the wavelength if I recall :-)

Electric fields are so much easier...

One interesting thing here is that across distances like this,
there would be significant longitudal currents in such a shield.

Not as bad as metal spanning the Mississippi, but getting there.



Skin depth is probably a good place to start with in roughly estimating
the thickness needed.  In copper at 50 Hz, a quick calculation suggests
9.5 mm, but this just the depth at which the E-M field decreases by 1/e
or 8.7 dB.  Thus to get 20 dB attenuation this implies a thickness of
about 22 mm, etc.


While interesting, I think you are going overboard. The easy remedy is 
to move the fiber of the power-cable and put it on some distance, just 
choose a different path for it in the building.


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

[Alex Pummer]

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


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


73

Alex


On 8/21/2016 3:21 AM, Attila Kinali wrote:

On Sun, 21 Aug 2016 04:46:10 + (UTC)
Bob Albert via time-nuts  wrote:


I was interested in this, but my needs are mostly below 100 MHz.
I wonder what could be done similarly for this lower range...

As Orin mentioned, there are some designs for that range out there,
best known are probably the two Orin listed (N2PK and the VNAW by DG8SAQ).
Although these are good designs, they are not as good as the one by
Henrik Forstén. Henrik addresses many issues that the other leave out
for simplicity.

What I would do instead is use Henrik's design and do some adaptions.
There are four parts that limit the frequency at the lower end:
the signal sources, the filters for the sources, the mixer and
the directional couplers.

For the signal source there are two choices: DDS and down-mixing.
The DDS is probably the obvious choice and delivers good results,
but limits the maximum frequency if you have price limit.
The down-mixing approach uses one of the PLL's with VCO as the
original design uses, but only within a limited range, eg around
200MHz. This signal can then be down-mixed using a crystal oscillator
(or another PLL+VCO) and a suitable mixer (eg LTC5512 or a DIY diode mixer).
Advantage of this is, that the spurs of the PLL+VCO can be surpressed
to a large extend, as the frequency range is quite narrow relative to
the output frequency of the PLL+VCO.

For the directional couplers, the approach used with Henriks design
will not work for low frequencies, as this type of coupler needs a length
of approximately lambda/4 to work optimally. I.e. they would become
unweildingly large. The two choices I am aware of for the lower frequency
ranges are transformer based directional couplers or resistive bridges.
Transformer based couplers have the disadvantage of a non-flat frequency
response and an upper and lower frequency limit, given by the characteristics
of the transformer (number of windings/inductance and the used ferrite).
Their advantage is that they have very little loss. Resistive bridges on
the other hand have a loss of 3db (respectively a -6dB signal at each output),
but are totally flat down to DC and up to several hundred MHz or even GHz if
RF resistors are used.


Most of the above mentioned methods have a lower frequency limit somewhere in
the range of 20kHz and ~100kHz. If you want to go below that limit, you will
need to adapt the circuit further:
For the signal source the DDS approach is the only one that will result
in a good SNR at a reasonable price. Easiest way to go is to use a 16bit
DAC at >1MHz and an uC or FPGA to feed it (but use some low jitter oscillator
as clock source for the DAC). The other components in the signal path
that are limiting are the baluns and mixers. I would get rid of those two
all-together and digitize the signal from the directional couplers directly
using an ADC with >1Msps and 16-18bit. If you limit yourself to the range
of 10Hz-20kHz, you can do all this using audio ADC/DACs and get a very
high performing system.

Attila Kinali



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Re: [time-nuts] Heathkit clock available

[Alex Pummer]

Thank you Tom, I have a very primitive frequency comparator built some 
thirty years ego, which compares the line frequency to WWVb 60kHz, since 
the new format for WWVb was introduced it does not work so great any 
more, but it is still good enough to see if the line frequency is to 
fare off. Basically it is just counting the periods of the line 
frequency and the counter's gate time could be set for hour/day/ 
week/month and the reset time is derived from the WWVb datum. I have 
seen also some daily deviations of the 60Hz similar what your picture 
shows, but interestingly the long time average -- one whole year -- up 
to now is correct


73
KJ6UHN
Alex



On 8/12/2016 11:03 AM, Tom Van Baak wrote:

before you buy AC line disciplined clock read that

Alex,

That old article from 2011 is misleading. It correctly describes what was being 
/proposed/, but it turns out NERC chose not to implement what the article 
(fears) talks about. There are lots of time-nuts postings about this in the 
2011 archives if you want to read more. Or google for TEC (time error 
correction).

So your 60 Hz timekeeping is probably fine and still loosely locked to UTC. Several of 
us time nuts continuously monitor mains frequency & phase for fun. It's an 
interesting and low-cost entry into the world of time & frequency measurement, 
long-term data logging, data analysis, Allan deviation, etc.

Here's a quick plot showing the last 2 months (US western grid). Someone else 
(Hal?) can double check it.

http://leapsecond.com/pages/mains/mains-june-july-2016.gif

/tvb

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Re: [time-nuts] GPS antenna selection

[Alex Pummer]

Hi Herbert,

just look the loss of the cable at 1500 MHz, and you will start to cry 
at 1500MHz tha cable will have cca 30dB for a 30meter long 
piecebasically that RG174 looks very nice with that small antenna 
but that is the only positive aspect. Meinberg in Germany has one 
up/down converting system, which makes it possible to go more than 50 meter.
On the other hand if you could stay on the balcony and use the cable 
which came with the antenna, 2m  to 3 meter,  you could have a good 
working system, but with 15m RG174  is asking to much. For 1500 MHz BNC 
is not the best solution,

73
KJ6UHN
Alex
P.S.: wo ist diese "Austrian countryside"

On 8/4/2016 2:29 PM, Herbert Poetzl wrote:

Dear fellow time-nuts!

I'm currently investigating my options regarding
GPS antennae (of course for time related purposes)
and I'm really confused by the variety they come
in ... (my apologies in advance for the long post).


Setting:

I'm living in a three storey house with a sloped
roof, a covered balcony and a larger garden with
huge trees on the Austrian countryside (Europe).

I've walked around with my smartphone (older one)
and I get a GPS position fix within 35s in the
garden (nine satellites shown), within 100s on
the balcony (also nine satellites), and not a
single satellite can be seen indoors.

The obvious choice would be to put the antenna on
top in the middle of the slanted roof for a perfect
sky view, but this brings a number of problems as
the roof is very hard to reach and quite high.

I have my 'lab' at the floor where the balcony is,
so I'm considering putting an antenna there and
run about 5-15m of coax cable to the GPS receiver.
The advantage there is that the antenna would be
somewhat protected (it still gets very hot during
summer and very cold during winter, but no rain
and no snow) and easy to reach for maintenance.

The third alternative would be to put the antenna
somewhere in the garden and have a rather long
cable running to the house and up to my lab.


Antennae:

Looking on eBay and Amazon shows a huge pricerange
for active GPS antennae with and without cable.

It seems to start at about 10 bucks with rather
small black boxes [1] designed for cars, probably
containing a 25x25 ceramic GPS antenna and an
amplifier, progresses over very interesting out-
door constructions for boats and whatnot [2] in
the 20-100 bucks range and finally tops with high
end devices [3] way above 100 bucks.

The information about the cheap devices is usually
very scarce, but typically boils down to:

  1575.42 +/- 5MHz
  24-28dB LNA Gain with 10-25mA at (3-5V)

  7dB f0 +/- 20MHz
  20dB f0 +/- 50MHz
  30dB f0 +/- 100MHz

They seem to use RG174 and come with SMA as well
as BNC connectors (and a number of others as well).

The mid range devices seem to use larger antennae
with smaller tolerances (+/- 1MHz) and larger
voltage ranges for the amplifier (3-13V).


Questions:

  - What are the key specifications which need to
be verified before buying a GPS antenna?

  - How can they be compared based on incomplete
specifications?

  - Is a place on the roof or in the garden worth
the trouble over the covered balcony?

  - Are there any typical pit-falls or general
tips and tricks regarding mounting and cable
connection to the receiver?

Many thanks in advance and my apologies again for
the rather lengthy post. Please feel free to point
me to previous discussion regarding this topic.

All the best,
Herbert


[1] 
http://www.ebay.com/itm/99-Good-GPS-Antenna-SMA-Screw-Needle-10m-Super-Signal-Navigation-DVD-Antenna-/171802461614
 https://www.amazon.com/Waterproof-Active-Antenna-28dB-Gain/dp/B00LXRQY9A

[2] 
http://www.ebay.com/itm/Standard-Horizon-XUCMP0014-GPS-Antenna-f-CP150-CP160-CP170/331364914004
 
https://www.amazon.com/Garmin-010-12017-00-GPS-GLONASS-Antenna/dp/B00EVT2HSE
 
https://www.amazon.com/SUNDELY®-External-Marine-Antenna-connector/dp/B00D8WAVTC

[3] http://www.ebay.com/itm/NEW-FURUNO-GPA018-Gps-dgps-Antenna-/182223355414
 https://www.amazon.com/Garmin-nmea-2000-orders-over/dp/B0089DU96A
 
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Re: [time-nuts] Effect of EFC noise on phase noise

[Alex Pummer]

Ja Gerhard, bitte schicke mir den LTSpice file,

Danke im Voraus und
73
KJ6UHN
Alex

On 8/1/2016 6:34 PM, Gerhard Hoffmann wrote:

Am 02.08.2016 um 02:42 schrieb Bruce Griffiths:

/"I'm working on a new amplifier based on IF3602 or BF862 FETs that can
use 10u foil only."/
/
/
Similar to that published by Groner in Linear Audio?
/
/
I know that Groner exists from some web site, but had no personal 
contact.
Also I don't read Linear Audio other than 2 articles from Scott Wurcer 
that I've bought.
I highly regard Scott, he's the father of the AD797 after all and AD 
fellow.

I also had some conversations with him on that.

The preamp will be classical.  Some JFETs in parallel, no source 
resistors except

half an Ohm for feedback, more would add to the input noise voltage.
Cascode with a Zetex bipolar (or whatever they are called now).
OP37 for loop gain. feedback from OP37 output for 50 or 60 dB gain.
Post amplifier to 80 db or so.
Without the cascode, the 1 MHz is not possible. It does not help that
the feedback limits the voltage excursions on the drain.

I'm not yet sure about the effective input capacitance. I get abt. 1 
or 1.5 MHz

bandwidth from a low impedance source. A few nF on the input capacitance
would be ok, in the end I want it after a ring mixer for phase noise 
measurements
but I get unreasonably more in simulation, depending on if I measure 
it from
upper frequency corner with a larger input resistor or the resonance 
frequency

with an added inductor.

You can get the LTspice file if you like.

regards, Gerhard

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

[Alex Pummer]

the Q factor could be derived from the modulation bandwidth of an 
oscillator [ the "old way" of measuring the Q of resonator of the 
running oscillator's ], therefore if we look the fluctuation spectrum of 
the frequency of an oscillator we could determine the Q. Any circular 
movement could be seen as the source of a harmonic oscillation.


73
KJ6UHN
Alex



On 7/29/2016 9:28 AM, Attila Kinali wrote:

On Fri, 29 Jul 2016 03:29:27 -0500
David  wrote:


Capacitors and inductors have an associated Q while lacking a resonate
frequency except for parasitic elements.  Their Q increases with
frequency up to a point; does that apply to a spinning body?  I guess
it depends on the loss mechanism.

The Q of an inductor (or capacitor) is defined at a specific frequency.
You can see it as the Q factor that would be achieved, if the inductor
(capacitor) would be paired up with an ideal capacitor (inductor) with
a value such, that it would result in the specified frequency.

Hence, if you increase the frequency, the Q factor increases for an inductor. 
Conversly, the Q factor of an capacitor decreases with increasing  frequency.

See also:
https://en.wikipedia.org/wiki/Inductor#Q_factor
https://en.wikipedia.org/wiki/Capacitor#Q_factor


Attila Kinali



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Re: [time-nuts] NCOCXO anyone?

[Alex Pummer]

it is a way to use a carrier fc to make one SSB  signal with fm 
modulation frequency, use just the side-band, , which have a frequency 
of fc + fm = fR,  [fR/fc is a function of the SSB modulator carrier 
suppression capability,]  fm could be from less than 1/2 fc any 
frequency to zero, if it is zero fR =f c. With fm is not zero, the phase 
of fR will advance relative to  fc as long as fm is not zero if fm 
becomes zero the advance will stop.
The generation of a very small frequency offset will need fm = the 
offset frequency
To "clean up" the resulting fR, a PLL could be locked to it, which could 
look to one single frequency only [with very narrow tuning range 
oscillator, perhaps a a tunable crystal and very narrow loop filter 
[just to let pass fm ]
since oscillators are by definition amplifiers with infinite high gain 
that PLL could look  into fc!
Attila I don't know anything about any patent, but I developed that kind 
of system for video colour performance analyzing system in the "past 
century".

73
KJ6UHN
Alex

On 7/29/2016 9:23 AM, Attila Kinali wrote:

On Fri, 29 Jul 2016 00:26:07 + (UTC)
Bruce Griffiths  wrote:


Diophantine Frequency Synthesizer Design for Timekeeping Systems

I quickly went over the papers people have pointed me at. Without
having gone through all the math, the idea for choosing the PLL values
looks neat. The 2-cascaded synthesizer is also the one used by Spectratime
for their FemtoStepper, which bring us back to the question: How do they
achieve phase steps? I see how offset frequencies are generated (with
arbitrary small step sized), but I do not see how this can be turned
in fine resulution phase steps when using PLL's as the controlling elements.


Discusses a diophantine synthesiser.Note Sotiriadis' work on diophantine
numbers and frequency synthesis appears to be a rehash of an old Patent
perhaps due to a lack of competent searching for prior art.This issue was
discussed on the list some time ago,

Which patent are you refering to?

Attila Kinali


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Re: [time-nuts] NCOCXO anyone?

[Alex Pummer]

if you send the circuit to me Attila, I would try to help you

73
KJ6UHN
Alex
by the way aside of that ham license, I have some fifty years of 
experience and also an MSEE


On 7/28/2016 11:03 AM, Attila Kinali wrote:

On Fri, 22 Jul 2016 08:19:43 + (UTC)
Bruce Griffiths  wrote:


No, the first one merely uses a pair of cascaded heterodyne PLLs
as shown on p3 of the manual.

Ok. I tried to understand how this circuit works. While I can see
how a small and precise frequency offset can be produced, I do not
see how a small phase offset with fixed frequency can be produced.
At least not at the 100fs resolution level they are claiming in
the manual. Would someone be so kind and explain the working
of the circuit?


A diophantine setup may be useful here if one wished to construct something 
similar.

What is a diophantine setup?


Attila Kinali



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

[Alex Pummer]

in case the Earth, the circular frequency of the Earth is equal of a 
sinusoidal wave's frequency, which is a projection of the Earth circular 
movement in a plain, which is perpendicular to the axis of the Earth. 
The Q of the Earth in interpreted as the quotient of the phase speed of 
the  Earth's  circular rotation [or the projected wave's] and the 
fluctuation of the phase speed.


73
KJ6UHN
Alex

On 7/27/2016 8:10 PM, Neville Michie wrote:

The discussion of Earth as a system with Q, but which is not resonant,
is a more extreme case than the CONICAL PENDULUM.

The conical pendulum has a simple form of a weight on a string, instead of 
oscillating
in one plane as a conventional pendulum, it swings around in a circular orbit
in the horizontal plane. It has a definite resonant frequency.
Now a simple pendulum oscillates kinetic energy and potential energy, but a 
conical pendulum
has constant potential energy and oscillates its energy from North-South energy 
to East-West
energy.
I believe that a conical pendulum still has the circular error associated with 
amplitude.

But will it be as good a time keeper as the simple pendulum?

A curious fact about the conical pendulum is that whereas the simple pendulum 
has earth
rotation forces that show in the Foucault Pendulum, the conical pendulum has a 
different
period depending whether is swings clockwise or anticlockwise due to the earths 
rotation.

What do you think?

Cheers,
Neville Michie
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Re: [time-nuts] The home time-lab

[Alex Pummer]

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

K6UHN Alex


On 7/24/2016 4:23 PM, David wrote:

On Sun, 24 Jul 2016 14:45:02 -0700, you wrote:


Hi Bob:

The Sola 500 VA transformer is specified to hole up the line voltage for 3 ms.  
(but not a half cycle of the line
frequency).

I've connected the Sola CVS transformer to the output of the APC RS1500 backup 
UPS.  (needed to replace the 2 batteries
in the main unit and probably within a year the 4 batteries in the optional 
battery pack.
http://www.prc68.com/I/Sola_CVS.html
http://www.prc68.com/I/PC.shtml#Backup_UPS

The Sola transformer is connected to the output of the RS1500.  This will clean 
up any spikes or narrow drop outs on the
AC line since when the AC line is active the UPS does nothing.
My hope was that the transformer would clean up the modified square wave output 
of the UPS, but that does not happen.
Video of APC self test showing waveform on scope:https://youtu.be/DLE0mzAt7KY 


Was the Sola transformer under load when you ran the test?  I thought
a minimum load was a requirement for proper operation.  Maybe it is
time to get an online UPS or power conditioner but then you would not
need the constant voltage transformer.

Was the peak voltage still 170 volts?  If so then maybe it does not
matter.  Capacitive input loads and PFC power supplies should not
care.


I think the modified square wave killed my HP 6200 flat bed scanner.  The best 
scanner I've used and no longer made.

Ouch.  That is not suppose to happen but apparently some switching
power supplies have problems with modified sine outputs even though
they should not.

I have been told a couple of times that PFC power supplies are even
more likely to have problems with modified sine inverters but I have
yet to find an in depth discussion of the problem.  The PFC stage
should work with any input wave shape.
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Re: [time-nuts] HP5370 power supply measurements

[Alex 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 quite


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] Divide by 3

[Alex Pummer]

utilizing rising and falling edges makes the circuit output signal duty 
cycle sensitive to the input signal's duty cycle, and therefore the 
harmonic content will vary with the input duty cycle variation.

73
KJ6UHN
Alex

On 6/8/2016 9:47 AM, Richard (Rick) Karlquist wrote:

The URL you cited doesn't have the schematic in any obvious
place.  However, using both edges of the clock to supposedly
result in 50% duty cycle output depends on having 50%
duty cycle at the input.  If you have differential logic
like ECL, this can be realistic.  Single ended logic,
questionable.

The other issue is that the divider can start up in any
one of 3 phases with respect to any other frequency
dividers in your system, unless you do something to
synchronize the various dividers.

This is probably old hat to most readers of time-nuts, but
I just wanted to mention it in case some were unaware
of it.

Rick

On 6/8/2016 6:55 AM, Nick Sayer via time-nuts wrote:
I’m contemplating trying my GPS board with an FE-405B. That’s a 
different kettle of fish, but at the end of that, if I’m successful, 
one of the goals would be to be able to use it for the external 
reference of my 53220A. Unfortunately, 15 MHz isn’t one of the 
options - only 1, 5 and 10.


So I did some googling and found a divide-by-3 circuit using 
flip-flops, and then designed a board for it:


https://oshpark.com/shared_projects/jxXp7wYM

The circuit uses 3 D flip-flops and 3 NOR gates and has a 50% duty 
cycle output that’s 1/3 the frequency of the input. The OSHPark 
project has a pointer to the original blog post that has a schematic. 
The only difference between their schematic and mine is that in 
theirs, the third flip-flop has an inverted clock input. The third 
NOR gate inverts the clock to achieve that in mine (also one 
flip-flop and one NOR gate are unused and have the inputs tied high).


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

[Alex Pummer]

"Could you elaborate on this a little if time permits? I'm more a 
'digital person' but it sounds interesting. Thanks in advance, Herbert "


Yes Herbert
here is;
first divide 24MHz by two you get a very good quality absolute 50% duty 
cycle 12MHz, than you feed that 12MHx into mixer [which could be a 
transitional gate like HC4066 ] the other --LO input of the mixer you 
need to drive with a 10MHz oscillator, the output of the mixer will be 
2MHz, which you filter amplify and using to drive a freq multiplier, you 
have to multiply by 5 to get 10MHz  that is your 10MHz input of the 
mixer's LO port,
That was a very old style but very reliable way to do and since you have 
the LC filters you will not have to much jitter issue.
Also you could go a more modern way; divide the 24MHz by 6, but make it, 
that you have 50% duty-cycle  [you could make it with a CMOS device,  by 
loading during the counting a hex counter ] use one 10MHz better quality 
crystal oscillator, of its output has to be divided by 5 also with 50% 
duty-cycle output! than use one EX-or style phase detector and close the 
loop with proper filter. Depend on the quality of your crystal 
oscillator you will have a very low phase noise 10MHz source.
And you could make a few other variant by mixing the idea of the two 
previous and others .
It is important to use the components at the frequency at which they 
well perform, but keep the phase comparation at as high frequency as you 
could [side bands are easier to filer out if they are fare away from the 
carrier ], also use proper shielding and power-supply filtering

73
KJ6UHN
Alex

On 4/8/2016 3:13 PM, Bob Camp wrote:

Hi

If you start from a 24 MHz TCXO (different modules use different TCXO’s):

On an 8 MHz output, most of the time you divide by three.

On a 10 MHz output, you need to divide by 2.4. The net result is that you
divide by 2 sometimes and 3 other times.

In the 10 MHz case, there is a *lot* of energy at 12 MHz and 8 MHz, along with
the 10 MHz output.

In the 8 MHz case, most of the RF energy is at 8 MHz.



To correct the output by 1 ppm on the 8 MHz output, you need to either drop or
add one pulse out of every million pulses. Effectively you divide the 24 MHz by
2 or by 4 when you do that. You get a bit of 12 MHz or a bit of 6 MHz as a 
result.
That can be filtered out with a RF filter. The same is true with a (somewhat 
more
complex) filter on the 10 MHz output.

In addition to the “big” RF spurs, you get a low frequency component to the 
output
modulation. You are “phase hitting” the output eight times a second. That gives 
you
an 8 Hz sideband along with the further removed stuff. Since it’s not simple / 
clean
phase modulation, there are more sidebands than just the few mentioned above.

What messes things up even more is that you never are quite doing one ppm. You 
are doing
corrections like 0.12356 ppm this second and 0.120201 ppm the next second.
The pattern of pulse drop and add is not as simple as you might hope. The low
frequency part of the jitter (and it will be there) is no different than the 
noise on
a 1 pps output. You still need to do very long time constant (or very narrow 
band)
filtering to take it out.

Bob


On Apr 8, 2016, at 7:06 AM, Herbert Poetzl  wrote:

On Mon, Apr 04, 2016 at 06:07:54PM -0700, Alexander Pummer wrote:

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

Could you elaborate on this a little if time permits?
I'm more a 'digital person' but it sounds interesting.

Thanks in advance,
Herbert


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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[time-nuts] Oleg' s PN test Re: A new member & PN test set

[Alex Pummer]

Hi Oleg,
" If somebody is interested I can share all the information about it. "
Yes I would be very interested to see your phase noise test at least the 
principle

73
KJ6UHN
Alex


On 3/28/2016 6:49 AM, Magnus Danielson wrote:

Hi Oleg,

Welcome. As always, it's a combination of tools, experiments and 
theory which over a number of iterations develops into skills. You 
will notice that there is quite a bit of hams here too, some just 
forget to give their signals.


73 de SA0MAD Magnus

On 03/27/2016 10:25 PM, Oleg Skydan wrote:

Hi list,

I am in a process of making a low noise frequency synthesizer for the
1st LO
for my new DSP HF transceiver (http://neon.skydan.in.ua). This list 
is not
directly related to my project, but I found a lot of useful 
information in

this list - thanks for all contributors!

I see a discussion regarding "$40 phase noise test set". I have built
one and
already use it for several months. It is a great help in design 
process (I
am not "blind" anymore :) ). If somebody is interested I can share 
all the

information about it.

Best wishes!
Oleg
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Re: [time-nuts] Glass Envelope Quartz Crystals

[Alex Pummer]

I am perhaps to late now,I found the e-mail recently:
"

sockets can be an issue. With wire leads, you are asking for trouble.

Functionally, there is little there is little difference between a glass


package crystal


and a metal package. About the only real one is the obvious - one has a metal


shield

you can (but sometimes don’t)  ground.

Bob


"


the glass packed ones will have much better vacuum, therefore higher Q
I still have some KVG glass envelope crystals [116MHz overtone] from the 
60 -ties

73
KJ6UHN
Alex

On 2/2/2016 2:37 PM, Bob Camp wrote:

Hi

I think you will find that the Russian versions were used without ovens for a 
long time. In the US, the only
use for the glass packages past the mid 1960’s was in ovens.

Bob



On Feb 2, 2016, at 1:43 PM, iovane--- via time-nuts  wrote:

I think that these crystals were designed to be placed in an oven, which worked
as a shield too. I have a similar crystal made by Racal in the 60's, and in my
case it is fitted with the classic octal tube-type plug. It was housed (still
is) in a heavy massive shimmering chrome-plated cylindrical brass enclosure, a
beauty to see, It was the timebase of a tube-type synthesizer with lots of
tubes. Themperature control was achieved by means of a mercury thermometer in
which mercury actuated a contact when reaching a wire crossing the capillary
tube.

Antonio I8IOV


Da: Bob Camp 
Data: 02/02/2016 13.15
A: "Discussion of precise time and frequency measurement"
Ogg: Re: [time-nuts] Glass Envelope Quartz Crystals

Hi

Since the 25 MHz crystal has already been soldered into a circuit, putting it

in a

socket is probably not a real good idea. It’s also a leaded part. Even with

fat pins

sockets can be an issue. With wire leads, you are asking for trouble.

Functionally, there is little there is little difference between a glass

package crystal

and a metal package. About the only real one is the obvious - one has a metal

shield

you can (but sometimes don’t)  ground.

Bob



On Feb 1, 2016, at 9:58 PM, Daniel Watson  wrote:

Hi,

I purchased a pair of interesting glass envelope crystals for a project.
Here are some pictures:

http://syncchannel.blogspot.com/2016/02/glass-envelope-quartz-crystals.html

Does anyone have an idea about what mount/socket I should buy for these? I
read a previous thread on the list about Bliley crystals using a B7G mount,
but I'm not sure if that type might work here.

Also, when building up a circuit to make these oscillate, are there any
specific differences about crystals in this package that I should keep in
mind?


Thanks much,

Dan W.


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Re: [time-nuts] 10 MHz to 32.768 kHz converter

[Alex Pummer]

every injection locked oscillator has jitter, since the oscillator 
slowly --depend on the "tank circuit"s Q will return to it's original 
frequency, what will be interrupted by the next injection, therefore the 
oscillator will have a larger phase jump during the interaction with the 
pulse.
"how fare the oscillator could get" is depend on the "tank circuit"-'s 
Q, therefor the jitter in worst case could be a whole period of the 
oscillator, which is   1/100kHz = 10usec
in case the locking pulse does not let the oscillator go to fare away 
the jitter will be less, but the jitter will be always a dependence of 
the Q of the oscillator's "tank circuit  in this case the crystal, also 
the length of the synchronizing pulse -- the energy of the pulse is 
dependon it's length -- will influence the phase of the synchronized 
oscillator.
there was a very good  paper written on injection locking: R. Adler, “A 
study of locking phenomena in oscillators,”Proc. IEEE, vol. 61, no. 10, 
pp. 1380–1385, Oct. 1973


73
KL6UHN
Alex


On 3/21/2016 6:00 AM, Attila Kinali wrote:

On Sun, 20 Mar 2016 18:26:16 -
"Martyn Smith"  wrote:


I  have a real time clock calendar chip that requires a 32.768 kHz crystal.
I want to feed it with 10 MHz signal instead, so it is synchronised to my
main 10 MHz in a frequency standard I am designing.

Currently, all that has been discussed were digital solutions.
But what about using an analog approach?
If you have a 32kHz crystal oscillator, you can injection lock it
to the 10MHz signal, by dividing the 10MHz down to 128Hz, then use this
to form short (as in a couple of ns) pulses, which you then couple
to the crystal using a small (a couple of pF) capacitor.

Given that the crytsal has an accuracy of better than 100ppm, then
even a very weak coupling at 128Hz should be enough to keep it locked.
Upper bound on the jitter is 1/128Hz*100ppm=781ps (very simplified
calculation, but it should be definitly less than 1-2ns)

Attila Kinali



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Re: [time-nuts] Inside a CTS 1960017 OCXO

[Alex Pummer]

sometimes high frequency oscillators could get in certain mode of 
operation the "blocking oscillation" see here: 
https://en.wikipedia.org/wiki/Blocking_oscillator, also it could happen, 
that the high frequency oscillation does not stops entirely, just 
undergoes an amplitude fluctuation, that could cause side bands on both 
side of the carrier. Blocking oscillation could happen because of to 
strong positive feedback -- due to design error or component error. The 
dumping of that product on e-Bay also could be a sign of a to late 
recognized error

73
KJ6UHN

On 2/29/2016 2:04 PM, Gregory Muir wrote:

Not sure if I am missing something here or not but an early mention was made 
regarding synching the test equipment used to the 60 Hz line to see if the 
purported 60 Hz anomaly is actually synchronous or asynchronous.  I haven't 
heard anything regarding this since then.

Greg
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Re: [time-nuts] Inside a CTS 1960017 OCXO

[Alex Pummer]

Hi Dan
 how many of these oscillators have that low freq.hum?
73
KJ6UHN
Alex

On 2/27/2016 6:25 PM, Daniel Watson wrote:

Hi,

Attached is a plot of the output frequency difference from 10MHz during
warm-up. I believe this indicates the crystal is SC cut.

The VREF and EFC pins on the unit do work. The VREF is 4.1V.

I probed around the board of the unit I cracked open and found a low
frequency oscillation. It seems to vary from 40 to 90 Hz depending on where
the unit is in the warm-up cycle, and what I'm doing to it. With the can
cut off, the unit draws almost 50% more power than normal trying to
maintain temperature, so it's possible this is offset from what has been
reported in normal units.

In the photos, you may have noticed two sets of large, unpopulated pads on
the board near the output. I experimented with putting 10uF capacitors
across those. That killed the output, but the low frequency oscillation
could still be detected further back in the circuit.


Dan

On Sat, Feb 27, 2016 at 1:10 PM, Joseph Gray  wrote:


Nice teardown. I was looking at that listing just yesterday. I am tempted,
but don't know what I'd do with 40.

The real question is, how do they perform?

Joe Gray
W5JG
On Feb 27, 2016 9:48 AM, "Daniel Watson"  wrote:


Hi,

I'm sure many of you are tracking the cheap CTS 10MHz OCXOs available on
eBay right now. I purchased a case of them, and decided to crack one

open.

I took pictures along the way, thinking that might be interesting to the
list. Here is the blog post if you are interested:




http://syncchannel.blogspot.com/2016/02/10mhz-ocxo-teardown-cts-1960017.html

Comments on the internal construction of the OCXO are welcome. It seems
pretty straightforward inside though.


Best regards,

Dan W.
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Re: [time-nuts] GPS Outage..

[Alex Pummer]

Hi Burt,
you are more than right, but don't forget the bean counters! they have 
power over everything even logical thinking.

73
KJ6UHN
Alex

On 2/26/2016 8:57 AM, Burt I. Weiner wrote:
Maybe I'm misreading what you're saying, but no matter the cause, it 
points out what can and does happen when you put all the mission 
critical eggs in one basket.  That we don't have as reliable as 
possible a backup system, or why we destroyed the one we had, is mind 
boggling.  This is a perfect example of what happens when you have 
people who don't understand the problem/s making the wrong final 
decisions in spite of having been warned.


It is my belief that if we are to be so reliant on these systems for 
so many things, we need to have a functioning backup system in place.


Burt, K6OQK




Mark Sims wrote:
>> When is some organization going to explain what happened in 
February for almost two hours starting at 00:16 GMT?  That subject 
has gone silent.  Rob, NC0B
> I heard back from NAVCEN.  They said it was a Trimble issue and 
that Trimble would contact me (they didn't).   But that does not jive 
with reports of failures in Motorola, Navman, etc receivers.


I think we need to distinguish here.

The January 26 issue was due to faulty data sent by the satellites,
which caused GPS receivers to apply a wrong UTC correction which caused
the UTC time to be off by 13.7 us.

As explained by Luc Gaudin from http://naelcom.com (who obviously sell
Trimble GPS receivers) the February 13 issue was indeed just a Trimble
firmware problem. See:
https://www.febo.com/pipermail/time-nuts/2016-February/096042.html
https://www.febo.com/pipermail/time-nuts/2016-February/096050.html

Martin


Burt I. Weiner Associates
Broadcast Technical Services
Glendale, California  U.S.A.
b...@att.net
www.biwa.cc
K6OQK
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Re: [time-nuts] MTI 260-0624-D OCXO

[Alex Pummer]

Hi Mike,
Would you be so kindly and post some pictures of the opening process of 
that OCSXO ?

73
KJ6UHN
Alex
On 2/18/2016 7:54 PM, time...@metachaos.net wrote:

Bob,

The vendor has said that they did not want the unit back. So...

I opened it up. Crudely, I admit. I learned a few things. I was concerned
about the outer case heating up too much when I was trying to remove the
solder. Turns out that the outer case doesn't touch anything except the pins,
so it can get pretty hot without any damage. Unfortunately, I used a bit of
brute force to remove the casing after scraping away as much of the solder as
I could and after cracking the solder seal with a hammer and screw driver.
Even using more heat, I'm not sure of the best way to remove the case. Neither
solder wick nor a vacuum desoldering tool is likely to remove all of the
solder between the top case and the bottom.

Even so, I got the case off. Somewhat bent, even bent the bottom circuit board
a bit. I discovered that there is a 2mm hole in the top that allows a variable
resistor to be adjusted. You need a pretty long, small screwdriver / adjusting
tool to do that, but that is probably for setting the center point. I would
try to remove the solder rather than drilling, or drill upside down to prevent
solder flakes from falling inside.

Also, I found that the -D on my part number appears to correspond to the board
revision, which is marked "Rev D". So the -C and -D parts probably have the
same specifications. And, on the inside there is a marking "92.0" which I
believe would be the set point for this specific crystal. So if I took the
crystal out, I would know where to design the set point for a custom unit
(currently beyond my skills, but who knows...).

 From there, I removed the bottom casing. That caused additional damage, some
lifted traces and even one very small part (tiny, SMD, who knows?).

But, I then soldered wires directly to the board, making patches for the
lifted traces.

I plugged it in.

I turned it on.

Success!

I gave it 12v which should supply 2A, but it dropped the voltage down to just
over 9V. Even so, I got a nice sine wave out at around 4.999790Mhz according
to my (uncalibrated) scope and around 800mV (into 50 ohm, DC). That was with
nothing attached to the adjustment pin. After some time, the frequency
stabilized at 5.14Mhz and the voltage came back up to 10v. When I attached
the adjustment pin to ground, there was no change. When I attached the
adjustment pin to Vref (which is at 6.15v), the frequency dropped to
5.10Mhz. So apparently, these units adjust negatively. But also have a
very wide adjustment range of 4Hz (8e-7). I am assuming that the adjustment
range is 0..6v. I attached the adjustment pin to +10v and the frequency
dropped another 3Hz for a 1.4e-6 adjustment range.

I don't expect that this specific unit will be very useful given the damage
that I caused opening it up. But, probably there were just bad connections
internally, so if I were much more careful in the disassembly, I could
probably have fixed it. Something to keep in mind for the next unit.

I may be wrong for what the variable resistor does. Turning it made no
difference in the frequency.

I also suspect, but don't know that the difference from 5Mhz is due to the
frequency counter being uncalibrated. It could also because I damaged the unit
or just because it is very far off from where it should be.

Still, I learned a lot, and well worth the time spent.


Mike



Hi
The one advantage you have in testing a used OCXO is you have a pretty good 
idea of how
you are going to use it. If phase noise does not matter to you … no need to 
test. I’d always check
that it tunes on freq with reasonable EFC range left over. I’d also make sure 
that it warms up
properly (oven works) and that it has a reasonable output. What goes on the 
list past that …
it depends on what you need.
The gear you have will check aging and get it set on frequency fine. It will 
check it for “wander”
as your lab heats up and cools down. With a GPSDO and a simple phase lock, a 
DVM may be
all you really need to do most of that. You will not have a proper ADEV, but 
you will know it works
pretty well (or not ..).
A lightbulb oven / bench / fridge /freezer proces can give you a wide range TC 
if you need it.
If you do get into phase noise, a sound card system will get you going. For 
ADEV, the 10811’s
tune far enough that a single mixer system with your 53131 will give you good 
data. Both
of those will involve some building, but not a lot of money.
There is one thing about the 10811’s: They are not sealed units. They tend to 
soak up humidity
when stored in most parts of the country. You may want to run them for a month 
or three
before doing any fancy testing.
Bob

On Feb 18, 2016, at 7:40 AM, Adrian Godwin  wrote:

I have a small collection of 10811 and similar oscillators here, collected
from hamfests rather than china (and mostly pre-ebay).

What sort of 

Re: [time-nuts] MTI 260-0624-D OCXO

[Alex Pummer]

Hi Mike,
look for any kind of radio-receiver, which would receive around 5MHz the 
old 60 meter broadcast ban, connect to power any kind of wire which 
could serve as antenna turn it on and try to find WWW at 5MHz, after 
that power up your 5MHz oscillator connect piece of wire to the 5 MHz 
output and bring the other end close to the radio receiver's "antenna" 
which you installed before. I you are lucky you will hear a beat from 
the radio's speaker, now you could apply some tuning voltage to your 
oscillator, and if you change that tuning voltage the beat will change 
somewhat but no to much since that OXCO has  very narrow tuning range. I 
t could also happen that you do not hear any beat frequency, but a 
wabling [= very low frequency fluctuation] of the www, because your 
oscillator's and the frequency of the  www are very close to each other, 
frequency of beat is not audible. the frequency of the www will be not 
exact since it's propagation path is not stabile. That is enough to see 
of the OXCO is still "alive" and with a proper PLL it could be tuned to 
the correct frequency

73
KJ6UHN
Alex

On 2/17/2016 6:56 PM, time...@metachaos.net wrote:

Bob,

In this case, I know how it was taken off the board - it wasn't. They just cut
the board around it. I had to remove it myself. Nice thing about that, is that
I got a nice plastic, pre-formed part that fits between the board and the
OCXO, probably as an insulator.

You are also right about the number of things that you need to test to make
sure that one of these is fully functional. However, this is a "starter" OCXO
for me and I don't yet have the equipment to perform the tests. The best that
I can do is to make sure that, when powered up

1. I see something that sort of looks like a sine wave at a reasonable
   magnitude.

2. My 2465B CT frequency counter thinks that it is somewhere near 5Mhz.

3. If I apply gnd, or VRef to the adjustment pin I see the frequency change
   at least a small amount.

Without more equipment, there isn't much more that I can do to test. Unless
you have some suggestions?


Mike



Hi
Best guess is these things get taken off the board with either a big torch or a 
charcoal fire.
You can ask Mr Google to dig up pictures of the process. Depending on just how 
quick
they are, the insides of the OCXO can easily be reflowed. The likelihood of it 
reflowing and
cooling back to a reliable joint … not real good.
Bob

On Feb 17, 2016, at 5:16 AM, Andrea Baldoni  wrote:

On Tue, Feb 16, 2016 at 07:58:21PM -0500, time...@metachaos.net wrote:


I just received a 5Mhz OCXO from eBay (MTI 260-0624-D OCXO). After testing it,
it is clear that it is defective.

   1. It never heats up.
   2. The reference voltage is zero.
   3. Only noise is seen on the output pin.

I had the same issue with some of them. It's very likely that the internal
solder connections from pins to PCB are broken, at least, the one for power.
It happens because the inner oven is heavy and there isn't any thermal
insulator (besides air) to keep it from moving.

Wheter the crystal has been damaged or not, it's unknown. I had one where the
crystal actually fell off from its supports too.

I posted a link to photos of the internals, time ago. The link is dead now
and I don't think to have the photos anymore but perhaps someone downloaded
them.

Best regards,
Andrea Baldoni
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Re: [time-nuts] HP Reliability

[Alex Pummer]

Quite often it works, but sometimes it does not,
not to long time ego I had to investigate one non-linearity case with a 
high mode QAM signal, there was something, what not supposed to be 
there, the only spectrum analyzer which had enough dynamic range was one 
from Rohde,

73
K6UHN
Alex
 On 2/14/2016 11:20 AM, William H. Fite wrote:

They don't wonder; they know very well. But they're stuck. Consider
oscilloscopes. Why pay for a Keysight or Tectronix or LeCroy or, God
forbid, a Rohde & Schwarz when, for the vast majority of applications, a
Rigol will give you everything you need at 1/N the cost?

The hugely expensive, overbuilt gear that we grew up with is yesterday's
news; that's why we can scarf it up so cheap on the 'bay. Lots of labs and
manufacturing facilities now consider basic gear like DSOs, SAs, DMMs,
PSUs, and sig-gens as disposable as cell phones.

I'm not sure that is a bad thing.

Bill



On Sunday, February 14, 2016, Scott McGrath > wrote:


HP's greatest advantage of old was being the largest and best vertically
integrated technology company as innovations in one line of business were
often applicable to others.This was right down to things as prosaic as
packaging and or hybrid  circuit design

Now Keysight is just another mid sized technology company who outsources
much of their production and wonders why Asian vendors can copy their stuff
so rapidly and undersell them.

Content by Scott
Typos by Siri


On Feb 14, 2016, at 8:31 AM, Adrian Godwin  wrote:

HP built their reputation for quality and reliability with test

equipment.

Computers were always considered a bit weird (in a nice way, in the case

of

handheld calculators) but printers have followed the consumer race to the
bottom.

It's sad to hear that the instrument division are no longer focused on
keeping that reputation - perhaps that's why the medical division moved

to

separate the names.

On Sun, Feb 14, 2016 at 11:28 AM, Dr. David Kirkby (Kirkby Microwave

Ltd) <

drkir...@kirkbymicrowave.co.uk> wrote:


   On 14 Feb 2016 09:04, "Perry Sandeen via time-nuts" <

time-nuts@febo.com

wrote:

Hi,
It is rather depressing to me to hear RK and others remark about the

unreliability of HP test equipment.

There is one area where they had outstanding equipment.

I have a friend with a fairly large lab. He must have 50 signal

generators,

15 spectrum analyzers, plus plenty of other stuff. Mainly RF. Most is
HP/Agilent, but he has Rohde & Scwarz and Anritsu too. He finds the HP

the

most reliable.

Also Anritsu seem to charge a lot for calibration.  A recent repair to a
modern 6 GHz Anritsu signal generator resulted in the repair bill plus
£1200 GBP (around $1800) for calibration. That particular sig gen, which
was sold for mobile phone use, has an electronic attenuator that will

blow

up if a mobile phone is transmitted into it.

He used to think he preferred R signal generators to Agilent,  but the
reliability of the R has been poorer so his mind has been changed on
that.

I am sure every company has some products that have been very reliable

and

some less so, but I would dispute that HP is in general less reliable

than

other decent makes.

Support on HP is generally good, with the forums which are answered by
Keysight staff. (An annoying exception seems to be LCR meters and

Impedance

analyzers developed in Japan. The Japanese engineers hardly ever visit

the

forums so questions on LCR meters and impedance analyzers generally get

no

response.)

There are instrument ranges where other manufacturers seem better (e.g.
Keithley for electrometers), but overall HP/Agilent seem the best

choice to

me.

I know someone who is looking for a 20.GHz VNA. He just lost out on a
Windows based R VNA that sold on eBay for a bit over $7000. There's no
way a 20 GHz Windows based Agilent VNA would fetch so little.  This is
reflected in their higher resale values.

At least with the older stuff,, service manuals for HP are useful,

though

modern service manuals are less so.

Just my opinion.

Dave.
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Re: [time-nuts] 10 MHz phase comparison using Bruel & Kjaer type 2971 phase meter

[Alex Pummer]

Hi Luca,
look here:  http://www.clmt.de/service-manuals/
73
KJ6UHN
Alex
On 1/30/2016 12:49 PM, Luca Dal Passo wrote:

Hi All,
 while i was looking for an hp k34-59991A phase comparator on ebay in
order to make some long term measurements of frequency drift of a dut
against a reference (by logging the analog output of the meter) i found and
bought a Bruel & Kjaer type 2971 phase meter instead of the hp.
It is a very nice unit, with digital and analog readout, high resolution
and high precision.
The drawback is that it is a very low frequency device, specified for the
range 2Hz to 200 kHz.
So, to compare two 5 or 10 MHz signals i'm thinking to use two simple
double balanced mixer, some low pass filtering on the IF outs of the
mixers, and a common local oscillator of about 5,1 MHz or 10,1 MHz to
convert signals into the range of the instrument.
The actual frequency of the local oscillator does not metter, because it is
the same for the two input signal, and theoretically i could use even a
simple free oscillator, provided only the frequency falls in the correct
region regardless of phase noise and stability because their effects are
subtracted cancelling themselves. Anyway i think to use a simple ambient
temperature xtal oscillator for that.
What are your opinions? What i'm forghetting to consider? What kind of
drawback i have to expect?
The other question is about the availability of user/service manual (or at
least schematics) of the  Bruel & Kjaer 2971: i'm not able to find anything
on the net.
Many thanks!
Luca
IW2LJE
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Re: [time-nuts] HP Z3801A Internal Power Supply issues

[Alex Pummer]

power supply runs for a while, output current increases, but voltage 
stays correct -> problem is in the load circuit, load circuit working 
for a while load current increases, but it recovers after pause -> look 
for some tantalum capacitor in the load circuit, they recover often  a 
few times before they finally die,

KJ6UHN
Alex

On 1/30/2016 6:21 PM, Artek Manuals wrote:
My Z3801A began to die over the last few days. It would work for an 
hour or two then produce a receiver error and communications problems. 
Turn it off, let it sit awhile, back on and it would start the survey 
and then begin to recover. Tonight it finally went dead with high 
current on the main input . The feed supply has a 2amp current limit 
so I have not blown the two 3amp fuses


I have a schematic of the supply reverse engineered by Stefan 
Hegnauere a few years ago (thank you very much) and a limited theory 
of operation description so I am not totally dead from a 
troubleshooting point of view although if one of the DC-DC converters 
is dead then I will likely have to scrap the supply


Questions
1) Any prior experience as where to look first I checked the 
electrolytics and at first glance they seem fine, no loss of magic 
smoke or any parts obviously hot or bulging. ESR 's look good on those
2) Will this supply function unloaded while I troubleshoot it on the 
bench out of the unit?
3) Anyone tried independent powering the Z3801? looks like two 5V 
supplies and +/- 15V..not hard to to do

4) Anyone with a good supply from a parts unit want to part with same?

Dave
NR1DX
ArtekManuals.com



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Re: [time-nuts] SMD TADD-1 distribution amplifier - seeking comments and suggestions?

[Alex Pummer]

That noise could come also from the environment, even trough ground-loop 
with the cox cable [ if the cable is connected between two grounds and 
the cable is long enough it will pick up noise since the noise-current 
generates voltage drop along the cable's shield, but the same field does 
not drives current trough the internal conductor of the cable thus 
causes noise voltage difference at the end of the cable between the 
shield and the internal connector.
Take a piece of coax cable put a connector[ preferable an N connector] 
to one end of the cable, short the internal connector of the cable to 
the shield at the other end and touch that connected shield/internal 
connector cable end to a larger metal
object, while the N connector end is connected to a spectrum-analyzer 
input, set the spectrum-analyzer to high sensitivity and you will see 
all the local AM and FM stations "coming out" from a perfectly shielded 
coax cable...
Also the power supply of the amplifier needs a good filtering [chokes, 
damping resistors damping ferrites, feed trough capacitors with relative 
large value up to 0,1microFarad range. and any wire loop works as an 
Antenna, therfore twist the power wires and keep close to metal surfaces

The box of the amplifier need to be closed without any small slots
to get good shielding with more than 120dB attenuation is not trivial,
73
KJ6UHN
Alex
On 12/17/2015 7:20 PM, Bruce Griffiths wrote:

Also add

1) BNX002
(attenuates noise in 1MHz to 1GHZ region) between the dc input and the input to:
2) Simple LCR filter - attenuates from 10kHz to 10MHz (see attachment)
Output of which is connected to the regulator input.

3) Like all the so called RF regulators with internal low pass filters your 
regulator is exceptionally noisy at low frequencies.
Try substituting something else - a good one should be at least 20dB quieter at 
low frequencies

4) Change the input amplifier to something like that depicted in 2nd 
attachment. Reduces complexity and effect of residual power supply noise. 
Reduce feedback resistor values.

Bruce
 On Friday, 18 December 2015 12:08 PM, Poul-Henning Kamp 
 wrote:
  


  
In message 
, Anders 
Wallin writes:


My 'ultra-low-noise DC-supply' in the form of a lead-acid battery improves
things somewhat, but some spurs still remain:
http://www.anderswallin.net/wp-content/uploads/2015/12/2015-12-17_fda_spurs_and_comments.png
interpretations and explanations are welcome!
The board was not enclosed in a metal can for these tests.

Isn't that the explanation ?

Any SMPS in the vicinity is going to show up...




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Re: [time-nuts] Phase microstepper designs?

[Alex Pummer]

it is not a hint, for what you asked, but if you add a DC voltage to the 
output of the phase detector in an analog PLL the VCO phase could be 
adjusted, similarly if you add a constants to the  input data of a phase 
accumulator of the NCO you could adjust the phase of the NCO

but be aware, the NCO will have always more jitter than a VCO
get Giora's book -- see my previous e-mail
also QAM demodulators used phase rotators too...
73
KJ6UHN
Alex
On 12/9/2015 2:26 AM, Attila Kinali wrote:

Moin,

I just tried to figure out how phase microsteppers are usually build,
but, beside the time-nuts discussion from 10 years ago and US patents
US4358741 and US4417352 my search turned out empty. I am pretty sure
that I used the wrong search terms and there should be lots of documentation
out there. Can someone give me a hint what to look for?

Attila Kinali



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Re: [time-nuts] RG 6 U couplings

[Alex Pummer]

if you have a good TDR -- you need very short 50 to 20 pico-sec. rise 
time -- you could play with cable to cable, but but not having such TDR 
the connector is a relative bullet prof solution

73
KJ6UHN
Alex
On 12/5/2015 1:36 PM, Bob Camp wrote:

Hi

Don’t worry about it. You will be under 1 db.

Bob




On Dec 5, 2015, at 3:28 PM, Bert Kehren via time-nuts  
wrote:

At my new home the GPS antenna location has turned in to a  challenge.  May
have to splice RG 6U. Has any one done measurements on  couplings and the
loss associated with them. Right now I am considering a  female, female
coupling. Is there a better alternative?
Thanks   Bert Kehren Palm City  Fl.
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Re: [time-nuts] GPS down converter question

[Alex Pummer]

and use low capacitive coupling, for simple adjustment of the bandwidth
the filter could be set up and tested with these HAM, stile network 
analyzers too,
if somebody explains me how to post pictures I could show the whole 
process, since I am doing it often for professional designs also

73
KJ6UHN
Alex

On 12/2/2015 8:44 PM, Charles Steinmetz wrote:

Alex wrote:

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


Mix 67 toroid cores are what you need.  Then it's easy.

Best regards,

Charles


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Re: [time-nuts] GPS down converter question

[Alex Pummer]

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 without it to see what happens. Can easily add it.
The LO will be a mini-circuits dsn-2036 followed by a 10 db amp to drive
the mixer another mini-circuit DBM. The IF drives a bpf-a76+ and then will
follow that with 30 db of gain at 75 MHz.
At least thats my thinking.
Regards
Paul
WB8TSL

On Tue, Dec 1, 2015 at 1:36 AM, Magnus Danielson 

Re: [time-nuts] GPS down converter question

[Alex Pummer]

Meinberg down-converter: IF 34MHz: 
http://digilander.libero.it/maurit0/transito%20ebay/GPS%20R%20Meinberg/gpsant.pdf

73
KJ6UHN
Alex

On 11/30/2015 2:02 PM, Magnus Danielson wrote:

Paul,

Many GPS receivers only use 2,046 MHz bandwidth, but some use the full 
20,46 MHz even if they only do C/A. Guessing that you are working on 
down-conversion for an old box, then 2,046 MHz will be your answer.


Cheers,
Magnus

On 11/30/2015 06:37 PM, paul swed wrote:

I am looking at building a GPS down converter.
LO 1500 Mhz locked to a 10 MHz ref.
The IF will be at 75.42 Mhz how wide should it be?

My question is simple.

What should the IF pass band bandwidth be?
Not sure if it should be 3-4 Mhz, 10 or 15 wide.

Thanks
Paul
WB8TSL
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Re: [time-nuts] Downsizing dilemma, HP 3335A

[Alex Pummer]

no wonder, at that climate, who wanted to there, move to the west coast 
like Fluke did, and you will find people

73
KJ6UNH
alias Dr.Dipl.Ing. Alexander Pummer, who once upon the time worked for 
you father


On 11/11/2015 6:05 PM, KA2WEU--- via time-nuts wrote:

I find it difficult in NJ to find  seasoned RF engineers...Ulrich
  
  
In a message dated 11/11/2015 9:02:03 P.M. Eastern Standard Time,

kb...@n1k.org writes:

Hi

Well, if you sit down with a bunch of these people and  talk to them, you
find out some interesting things:

1) When the job  postings go up, there aren’t many that ask about resistors
and capacitors.  They all ask about
firmware and processors.  The ratio is at least  10:1.

2) If you hold out for that job and go on the interview trip …  surprise …
it’s a sales job *selling* resistors or
capacitors or something  similar.That’s about a 4:1.

3) You hold out and keep on looking for  that job. You land one. You start
out all excited. A year later you  look
around. Everybody else got a bump in pay at the end of the year. You  ask
and the answer is “they work on
important stuff, you just do the easy  stuff”.  I’ve heard that about 100%
of the time (from both
sides of  the divide).

H …. so what choice would *you* make in that  job market?  And yes,
this is a (possibly biased) sample
across  several dozen people a year over the last ten or so years. Some of
them have  kept in touch and I’ve
been able to follow their up’s and downs. Some work  for the biggest of the
big. Some work for the smallest of the
small. All of  them are US based.

Hmmm … so now how do you feel about “guiding” them  to learn more about
hardware …I *know* how I feel.

Bob


On  Nov 11, 2015, at 6:26 PM, Rob Sherwood.  wrote:
  
The EE department at the University of Colorado has an enlightened

professor.

  http://ecee.colorado.edu/faculty/popovic.html

Zoya required  her students to not only get a ham license, but to build a

Norcal 40A.

  http://ecee.colorado.edu/~ecen2420/Files/NorCal40A_Manual.pdf

  
Most of the EE students had no idea what a resistor really was, let

alone have any experience in soldering a resistor or capacitor on a PC board.
One student stuffed the PC board, bent all the leads 90 degrees without
cutting any of them off, and then in effect flow soldered the whole bottom of
the PC board!

One wonders how EE grads today can actually get  a job and be productive

with so little hands-on experience.

  Zoya belongs to the Boulder (Colorado) Amateur Radio Club, and our

monthly  meetings are in the EE department. It is too bad this is likely an
unusual  example of what happens on campuses today.

Rob
  NC0B


-Original Message-
From:  time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Pete

Lancashire

Sent: Wednesday, November 11, 2015 10:01 AM
To:  Discussion of precise time and frequency measurement
Subject: Re:  [time-nuts] Downsizing dilemma, HP 3335A



I  can understand the downsizing, someday it will happen to me. And where

I live  there is pretty much zero interest in anything electronic. The two
local  schools Portland State and Reed both have EE but the students done
seem to  have any interest in anything physical. they believe everything they
need or  have interest in can be simulated on a computer. I helped one of
the PSU EE's  one day, just finished his 2nd year, had an old Kenwood stereo
distorted left  output. He pretty much had no idea what to do, and when 'we'
found the bad  transistor, he didn't really know how to replace it.

BTW I  know a Comp Sci graduate from PSU that can not write a program in

any language  that outputs "Hello World"

-pete Sad

On Thu,  May 23, 2013 at 5:08 AM, paul swed  wrote:
  

Bill
It is unfortunate when the time comes to  downsize. Even worse as time
goes by at least for me each piece  of test equipment from HP seems to
get heavier. Must be dust  building up inside. So as Ed says if you
need that fine grain  resolution you need them.
But you are also running into the age  thing in the gear and that there
are failures that creep in that  are really a big problem to figure out.
Especially if some form of  programmable logics involved.
Lastly sending them to the dumpster  is the worst thing. But then the
ole reality really sets in  selling packing and shipping the stuff.
I guess the good news is  that today there is a lot of replacement gear
that will do  reasonably well thats cheap respectively consumes little
power  and can easily be controlled by usb so you don't have to
actually  stop experimenting.
Regards
Paul
  WB8TSL


On Thu, May 23, 2013 at 2:32 AM,  ed breya  wrote:


You don't  save these kinds of synthesizers for high frequency
coverage,  but for their 10 to 11 digit frequency resolution. If you
  anticipate needing that, then of course they should be kept and
fixed. The long-obsolete telecom standard connectors and  ranges are
pretty much useless - sacrifice 

Re: [time-nuts] Digital Phasae Lock Loops

[Alex Pummer]

actually, that is a ketch 22, if the loop bandwidth is to low, you will 
have low noise , but it may will not lock at all, an other way to try to 
filter out the noise, also you may make the loop filter digital, but 
leave the the PLL analog, that could have  the possibility to have the 
advantage to be able to change the loop bandwidth  increase for locking, 
and reduce after the detected locking

73
Alex


On 10/17/2015 4:57 AM, Tom Van Baak wrote:

Martyn Smith wrote:

All we want to do is lock a 10 MHz ULN OXCO to a rubidium.
So basically a clean up loop.
Then we can provide an ULN output from the ULN OXCO and long term stability 
from the rubidium.
The 10 MHz ULN OXCO has phase noise of –115 to -120 dBc/Hz @ 1 Hz with a –174 
dBc noise floor.
The rubidium’s phase noise at 1 Hz is about –105 dBc.
So for the PLL to remove the poor rubidium phase noise I need a loop BW of less 
than 0.2 Hz.
I have tried digital PLL’s from other companies.  One you can specify the 
bandwidth down to 1 mHz.
But they are very unreliable, subject to flicking out of lock now and then.
At the moment we use an analog PLL with a loop bandwidth around 0.2 Hz.
That works well for my ULN OXCO’s that make about –113 dBc@1 Hz.
But now we are getting even lower phase noise at 1 Hz (-115 dBc and below), I 
need
a smaller loop BW, and we aren’t able to get that with an analog PLL.

Ok, thanks for the clarification. I'll leave it up to those with more 
experience to recommend a solution. I'd be surprised if using a digital PLL 
helps here. Are you sure you've reached the limit of what you can do with 
analog?

BTW, if your existing clean up oscillator is "very unreliable" consider that it 
may be your oscillator and not the PLL. For this you do not want to use ADEV or L(f) 
statistics. A one-time phase jump can cause loss of lock and averaging statistics will 
not tell you this. Instead you may want to look at the raw phase data and quantify the 
jumps. Occasional large jumps may not show up at all in an ADEV plot but can cause 
trouble for a PLL. Magnus, would MTIE be appropriate here?

/tvb

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Re: [time-nuts] UPS for my time rack

[Alex Pummer]

for a very similar application I am using a solar panel to charge the 
battery, but I have a vented NiFe battery, which is not sensitive of 
over charging or deep discharging, and has almost unlimited life time -- 
I have seen some in forklifts which were 60 years old and working...

73
KJ6UHN
Alex



On 10/10/2015 7:14 AM, Poul-Henning Kamp wrote:


In message <183218108.6a07c91c@Nodemailer>, "Chris Waldrup" writes:



Has anyone had bad experience noise wise with the APC brand units
like are available on Amazon and at Staples? I'd like to get one
that doesn't generate lots of RFI. Thank you.

Then don't.

Instead get 12 or 24 Volt sealed lead-acid batteries and a good
float-charger, and run your stuff from that.

You avoid a lot of conversion losses, and you get to decide what
quality batteries you want (As opposed to "the cheapest we can get
away with") and you get to decide how long hold-up time you want.

The important tricks are:

   1. ATO Fuse *RIGHT NEXT TO THE BATTERY*.  Not a meter away, but
  quite literally bolted right onto the terminal.

   2. Don't buy a shit charger, it will cost you battery life.

   3. Suitably sized fuse/polyfuses on all loads.

   4. Either put 0.010 Ohm current shunts in all over the place
  or buy a 1mA resolution clamp meter and prepare the wiring
  for measurement.

And that's it really...

I run all the always-on stuff in my lab from two 12V/105Ah telco-grade
sealed lead-acid batteries, and I'll never look back.

Presenty the load is 6.7A @ 24V, and that powers my ADSL lines,
firewalls (soekris), home server (ITX with mini-box.com PSU),
emergency lights (LED strips), GPS, GPSDO, HP5065 etc. etc.




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Re: [time-nuts] UBLOX LEA-5T Programming?

[Alex Pummer]

Hi Bert,
where could I get more inf on on that project?
73
KJ6UHN
Alex

On 10/10/2015 4:23 AM, Bert Kehren via time-nuts wrote:

We did a GPS PLL using ublox M7 not for time nuts but for Hams no u
processors, simple to build  with readily available parts with performance  of 1
E-10.. Hams still have get to gether and it would make sense to order the
parts. Boards would be less than $ 2 in quantity 10.  5X5 cm board can also
work with other VCXO's.
Data is attached
Bert Kehren
  
  





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Re: [time-nuts] Looking for ECL divide by 3 with symmetry

[Alex Pummer]

symmetry is better to look with spectrum analyzer, at good symmetry you 
should not see  second harmonic

73
KJ6UHN
Alex

 On 10/6/2015 12:28 AM, ed breya wrote:
Problem solved - one missing connection was fixed, and it now runs 
just fine. Symmetry looks good on a scope, and the toggle rate is 
plenty enough. It runs OK to beyond 120 MHz input.


Ed
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Re: [time-nuts] algorithms and hardware for comparing clock pulses

[Alex Pummer]

the role of the diode is just to have a voltage drop?
73
KJ6UHN
Alex

On 9/23/2015 11:31 PM, Bill Hawkins wrote:

Perhaps I can do this in words, as I have no schematic software.

Start with the input to your favorite microprocessor's A/D converter.
Connect it to a suitable (more later) capacitor to analog ground.
Connect a cmos switch across the cap and call it S2. When S2 is on, it
discharges the cap.

Now build or buy a constant current generator connected from a suitable
positive voltage to another cmos switch called S1.
When S1 is on, all of the current generated flows to analog ground.

To make it all work, connect the anode of a diode from the junction of
the current source and S1 to the cap and analog input.

When S1 is on, no current gets to the cap. When S1 is off, all of the
current gets to the cap, if S2 is off. This causes a linear buildup of
voltage across the cap, for a suitable time.

When 1 PPS pulses are compared, suitable means one second to charge to
almost the maximum that the micro A/D supports.
The value of I is chosen to overwhelm diode leakage and A/D input
current. The value of C follows.

All that remains for a working system is a pair of flip-flops to control
S1 and S2.
FF 1 is set by PPS 1 and cleared by PPS 2, and by power on reset. When
FF1 is on, S1 is off.
FF 2 is set by PPS 1 and cleared by an output from the micro when the
A/D conversion is done. When FF2 is on, S2 is off.

And so C will charge from PPS 1 to PPS 2, hold the value while the A/D
conversion occurs, and be reset to zero volts when the micro is done
processing the input.

This gives the micro a linear conversion of pulse difference time rather
than an RC exponential value.

Feedback controllers do better with linear error signals.

But all of this is wasted if the PPS signals are not accurate due to
things that affect pulse rise and fall times.

If the above was not adequately clear, please ask for clarification. Or
do a schematic and ask for corrections.

Bill Hawkins

P.S. This will not work well for small differences between PPS 1 and 2.
It will work if the goal is 50% difference, or 90 degrees phase shift.


-Original Message-
From: Can Altineller
Sent: Wednesday, September 23, 2015 2:56 AM

%< --

4. I think an analog solution like Bill Hawkins described, would be best
suited for this task. But I have not understood it enough to build it.

Best Regards,
C.A.


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Re: [time-nuts] Chinese GPSDO 10 MHz error

[Alex Pummer]

it is a bit more complicated FLL need circuit which is sensitive to 
frequency difference, it looks always,  PLL need a phase detector  and 
has a capture range, which is depend mainly on the bandwidth of the loop 
filter
there are combined phase /frequency detectors, which are sequential 
circuits/logic, usually with some uncertainty --and therefore more phase 
noise-- at zero phase difference

73

Alex


On 8/27/2015 1:50 PM, Attila Kinali wrote:

On Thu, 27 Aug 2015 17:19:34 +0200
Azelio Boriani azelio.bori...@gmail.com wrote:


The simplest form of a frequency locked loop is the XOR gate, when the
driving signals are 50% square waves. To achieve lock, the phase
difference will be proportional to the voltage needed to the VCO to
generate the desired frequency. Start with a 5V digital gate, suppose
your VCO needs 2.5V to be in frequency: the XOR output will be at 50%
duty cycle to generate, out of an RC, 2.5V and the phase difference
(between the reference and the VCO) will be 90 (or 270) degrees. The
difference will be more or less than 90 if the required voltage is
more or less than 2.5V (positive EFC) or will be more or less than 270
if the VCO has a negative EFC.

This is the description of a XOR gate based PLL, not an FLL.

The basic difference between PLL and FLL is very very simple:
A PLL measures phase, a FLL measures frequency.

The control loop then steers the measured value to be as close as
possible to a predetermined constant. As this steering loop is not
perfect, there will be a small error. Depending on what is measured,
it's either a phase or a frequency error.

Attila Kinali



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Re: [time-nuts] looking for SMT oscillator SC cut, with no oven

[Alex Pummer]

But if he needs 100dBc at 10Hz that is Wenzel's stronghold 
[https://twitter.com/ultralownoise]

look that:  http://www.wenzel.com/wp-content/parts/501-04517.pdf
73
KJ6UHN
Alex

On 8/26/2015 2:38 PM, Gerhard Hoffmann wrote:

Am 26.08.2015 um 22:04 schrieb Javier Herrero:


I suppose that one of the alternatives that you've explored are the 
ABLNO from Abracon http://www.abracon.com/Precisiontiming/ABLNO.pdf


looks just like this one from Crystek:

 http://www.digikey.de/product-search/de?keywords=cvhd-950 

but that fails the specs, also. If you have a good quality 5 or 10 MHz 
source in your

system, you can lock the VCXO to it and clean it up close to the carrier.

Last week, I asked for the prices of the 100 MHz Pascalls (not SMD but 
SMA)
but at  € 4K +VAT a piece I better make someone select crystals 
myself. :-(


Maybe Axtal has something.

They say that they are 3rd overtone, but it seems more an AT-cut than 
a SC, and anyway is around 10dB poorer


SC requires high temperature, that does not go together well with SMD 
and low power.



regards, Gerhard

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Re: [time-nuts] wtd: WWVB info

[Alex Pummer]

Thank you very much Tom,
73
Alex

On 8/24/2015 10:34 AM, Tom Van Baak wrote:

Don, Alex,

That IEEE PDF you're looking for has shown up on a .ru site. Google for Performance 
Analysis and Receiver Architectures and you'll see it near the top. I grabbed a 
copy to read and so far my PC isn't infected.

The thread that Daniel Engeler (the author of the paper) started on time-nuts 
is here:
https://www.febo.com/pipermail/time-nuts/2012-June/068021.html

/tvb

- Original Message -
From: Donald donvuko...@gmail.com
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Friday, August 21, 2015 10:03 AM
Subject: Re: [time-nuts] wtd: WWVB info



On 8/20/2015 9:31 PM, Alexander Pummer wrote:

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

Seems that this was covered 3 years ago on this forum:

see above


As noted is this link, getting access to this article is limited to IEEE
subscribers.

Did any one get the pdf as linked by Daniel Engeler 3 years ago ?

Thanks

don

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Re: [time-nuts] wtd: WWVB info

[Alex Pummer]

there is a complete description: 
http://www.worldcat.org/title/ein-digitaler-dcf77-empfanger-mit-hoher-empfindlichkeit/oclc/245812903

unfortunately the closest is in Hamburg, but I am working on it
73
Alex


On 8/24/2015 10:34 AM, Tom Van Baak wrote:

Don, Alex,

That IEEE PDF you're looking for has shown up on a .ru site. Google for Performance 
Analysis and Receiver Architectures and you'll see it near the top. I grabbed a 
copy to read and so far my PC isn't infected.

The thread that Daniel Engeler (the author of the paper) started on time-nuts 
is here:
https://www.febo.com/pipermail/time-nuts/2012-June/068021.html

/tvb

- Original Message -
From: Donald donvuko...@gmail.com
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Friday, August 21, 2015 10:03 AM
Subject: Re: [time-nuts] wtd: WWVB info



On 8/20/2015 9:31 PM, Alexander Pummer wrote:

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

Seems that this was covered 3 years ago on this forum:

see above


As noted is this link, getting access to this article is limited to IEEE
subscribers.

Did any one get the pdf as linked by Daniel Engeler 3 years ago ?

Thanks

don

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Re: [time-nuts] Cavity frequency air filled vs vacuum?

[Alex Pummer]

vacuum's dielectric constant is 1, air dielectric constant  is 1.00059 
at 1 atm, therefore the frequency with vacuum is higher, but with air it 
depend on pressure and humidity also

73
KJ6UHN
Alex
On 8/18/2015 9:49 PM, cdel...@juno.com wrote:

Hi everyone!

I'm trying to figure out what change if any to a cavities resonant
frequency would be when measured with ambient air pressure and then with
a vacuum inside. There will not be any pressure on the cavity when under
vacuum as the outside of the cavity will also be at vacuum. The cavity
frequency under vacuum will be 1420Mhz + (Maser frequency).

Thanks,  Corby

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Re: [time-nuts] A few questions about Tboltmon

[Alex Pummer]

an other way to keep lightening damage away,  to use one 1/4 wave length 
stud, and bank on it, that the lightening will not transmit with full 
power on the GPS frequencies.that trick is widely used on TV 
transmitter antennas, The only issue is that it is not very handy to 
have piece of cable, cca 4cm long, and the length of the cable has to be 
tried out with the available cable, -- with a piece of a semi-rigged 
cable teflon isolated,  the shorting factor is around 0,76.
If there is DC in the line, the end of the 1/4 wave length  cable can 
not be shorted, but connected to a large capacity -- up to 5µF ceramic 
SMD brick-capacitor, that will prevent the short and also a spike to 
travel on the line,
The stud length could be set with a network analyzer; the electrically 
1/4Wave length, and at at the end shorted coax cable looks like open or 
S11=0dB

73
KJ6UHN
Alex

On 8/14/2015 5:31 PM, Bob Camp wrote:

Hi

The GPS RX arrestors are something that come up from time to time.
They often have strange custom part numbers and very limited data.
Sometimes the only practical way to figure out what’s what is to buy one
and see. If it’s the right sort of unit once you check it out, the hope is that
there are still some left. An awful lot of these went into cell towers and
the install kits for them. The “give away” spec listed on the parts is often 
only
that they cover the GPS band and not much else. The crazy thing is that
often the enclosed instructions have a few details (often as cautions like
“do not exceed 25V or 2W RF”) that let you know you have the right gizmo.
I really can’t complain a lot about that. Since they are “nobody knows” sort
of part they go for  $20 and not  $50.

Bob



On Aug 14, 2015, at 7:37 PM, Gregory Beat w...@icloud.com wrote:

If anyone needs some if the Arrestors for outdoor GPS antennas
with F connectors (Trimble Bullet antenna) ... I think ai still have some 
spares
In my installation parts boxes.
Love to trade for an N version (which I ran out of), or postage and offers.

greg
w9gb

Sent from iPad Air

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Re: [time-nuts] wtd: WWVB info

[Alex Pummer]

one DCF77 receiver is described here: 
http://www.compuphase.com/mp3/h0420_timecode.htm
there are two files to download one for implement the MSF60 the other to 
implement the DCF77


 * A script file that implements a simple DCF77 decoder
   http://www.compuphase.com/mp3/dcf77.zip, that you can put on a
   CompactFlash card and run.
 * A script file that implements a simple MSF60 decoder
   http://www.compuphase.com/mp3/msf60.zip, that you can put on a
   CompactFlash card and run.

I don't know the details of the difference of the transmission between 
the wwvb and the MSF60, but they should be similar

73
KJ6UHN
Alex

On 8/11/2015 3:59 PM, Bob Camp wrote:

Hi

It’s *far* more likely that Everest will sell the IP on the receiver to each of 
the
“usual suspects”. Then the watch guys will each incorporate it in their micro
BGA chips that sit inside this or that watch. It will be in the same chip as all
the stepper drivers, display drivers, and other junk. Those are the guys who
have the money to buy the tech first.

Once they have it going (and the first to sign up probably gets a 2 year 
exclusive),
it migrates from the high end watches to the less exciting ones. At some point 
the
IP cost drops far enough for one of the clock guys to drop it onto an all in 
one BGA
for their gear. Might it be a bigger package - maybe. They probably have a 
bunch of
LCD segments to drive so maybe not. I’d expect it in a talking / walking / 
clock / radio/
weather station / phone / popcorn popper combo device first.

Until that part of the world is fully loaded with parts, there is not a lot of 
incentive
to go much further with it as any sort of stand alone receiver on a chip. That 
end of
the market is way smaller than even the clock market. Doubly so unlikely since 
it’s still being
fed quite adequately by chips that went out of production years ago. The only 
slight
chance would be to get some of the short run of demo chips that people will do 
to
validate the IP. You might still have to wire bond them up to use them ….

Thus the desire to get a sub $100 set of boards up and running as a very high 
performance /
modern radio. Even with fancy parts it’s not going to be over $200 for the 
hardware. If you go
with PHK’s basic approach (no FPGA / no fancy ADC / all software)  it *might* 
be $24.00 (single
piece board) plus shipping from Mouser (1,142 in stock) with a QVGA display 
included.

Bob



On Aug 11, 2015, at 8:18 AM, paul swed paulsw...@gmail.com wrote:

If you need time the GPS chips are the way to go.
Heavens for $11 I think you get the complete system with antenna.
The old wwvb chips do still work as well as they ever did. They detect AM
and thats still a part of the format. They are as reliable as they ever
were. (Sort of not if you live on the East coast) due to facts stated
already.
The new wwvb format indeed does improve on all of the issues stated. There
are papers written about it and are good reads.
So it could be worth while to build up a discreet receiver PLL and such to
recover the data. But as a company Everset has to find the market that will
keep them in business. I suspect thats why we do not see any products.
If they are successful I will expect something like the following.
Clocks that can decode time easily 99% of the time per day. I have measured
the am chips and they are sub 30% of the day.That these may be $50 or more
to start. They actually consistently work in any orientation. No more must
face west.
I hope they are succesful. But if you are a builder/programmer everything
you need is available.
Regards
Paul
WB8TSL

On Tue, Aug 11, 2015 at 3:14 AM, Chris Albertson albertson.ch...@gmail.com
wrote:


You might look into GPS devices.  They aren't quite as cheap as the WWVB

chips, but there are lots of them on the market.


Yes GPS receivers can be very cheap and self contained and much easier yo
use than those WWVB chips.  I have two of the chips.  I don't think they
work now that WWVB has changed format and even back in the day they only
worked for a few hours at night.  GPS is better.

But there is another good source for correct time.  Most people today have
WiFi in their house, at school and at work.  If the clock is going into an
area where WiFi  is available then it can connect to NTP.If the clock
connects to WiFi you can save money and parts count by not needing any
physical controls on the clock for setting or to control options as all
that can be done from a smart phone's web browser

--

Chris Albertson
Redondo Beach, California
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[time-nuts] Fwd: Trimble Thunderbolt CPR?

[Alex Pummer]

hi Skipp
please let me know if you find something I am in a similar situation
thank you in advance
73
KJ6UHN
Alex


 Original Message 
Subject:[time-nuts] Trimble Thunderbolt CPR?
Date:   Tue, 28 Jul 2015 12:11:35 -0700
From:   skipp Isaham via time-nuts time-nuts@febo.com
Reply-To: 	skipp Isaham skipp...@yahoo.com, Discussion of precise time 
and frequency measurement time-nuts@febo.com

To: time-nuts@febo.com



Trimble Thunderbolt CPR?

An Ebay purchased Trimble Thunderbolt arrived DOA, it has no rs-232 output
and I should also check the 10 MHz output soon. I'd like to have an initial
look at a diagram to see if there are any user serviceable parts on board.

Initial web searching suggests the schematic is not easily located.

Would anyone have a source (even if I have to pay for it) of a diagram and/or
any initial suggestions to trouble shoot an appearing to be dead Thunderbolt.

I have a working Thunderbolt available for relative comparisons, sitting right 
next
to the DOA unit.

Again, thank you in advance for your replies.

regards,

skipp

skipp025 at yahoo dot com

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

[Alex Pummer]

all of these oscillators, which do not deliver sinusoid output, have 
some threshold, which changes the form of  the original sinusoid wave 
shape -- since the best phase-noise performance could be generated with 
a resonator and resonators inherently generate sinusoid wave form -- and 
that said threshold is always modulated by noises [at least by thermal 
voltage noise]  which causes jitter- phase noise

73
KJ6UHN
Alex

On 7/25/2015 3:47 AM, Charles Steinmetz wrote:

Jerry wrote:


But back there somewhere is a sinewave.


Not necessarily.  Many oscillator circuits do not deliver a good sine 
wave to begin with (in which case you may need as much filtering to 
get a clean sine wave as if you started with an asymmetrical square 
wave), and many packaged oscillators have CMOS logic outputs (in which 
case you would have to break into the sealed package to get at any 
sine or sine-ish signal there may be).


Best regards,

Charles



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Re: [time-nuts] LORAN on the air 89700 been a good day so far

[Alex Pummer]

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.


---
This email has been checked for viruses by Avast antivirus software.
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Re: [time-nuts] LORAN on the air 89700 been a good day so far

[Alex Pummer]

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

73
Alex

On 7/20/2015 1:50 PM, paul swed wrote:

The system came up at 9 am and has been working well the austrons and SRS
fs 700 are doing very well. Some static crashes and such.

This test has however revealed something I did not want to know. The HP
z3801 seems to have a problem of jumping phase. So the trusty box is
finally showing its age. It will be quite a job to dig into.
Regards
Paul.
WB8TSL
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Re: [time-nuts] how to find low noise transistors

[Alex Pummer]

some old but very good papers:
 Roger Muat, “Choosing devices for quiet oscillators”,
Microwave  RF, August 1984, pp. 166-170.
Grant Moulton, “Dig for the roots of oscillator noise”,
Microwave  RF, pp. 65-69, April 1986.
Julio Costa et al, “Extracting 1/f Noise Coefficients for
BJT’s,” IEEE Transactions on Electron Devices, Vol. 41,
No.11, pp. 1992-1999, Nov. 1994
 “Simulating Noise in Nonlinear Circuits Using the HP
Microwave and RF Design Systems,” HP Product note 85180-
4, c 1993.
73
Alex

On 7/19/2015 8:00 AM, Azelio Boriani wrote:

Yes, I'm with Bob Pease: the soldering iron is my best simulation
tool. Nonetheless it is useful to know how to correctly extract the
coefficients to use in the best known among the simulation tools. In
one sci.electronics.design discussion, A. Lakovlev tells to have
determined the KF based on the datasheet's NF by trials and then
adjusted AF to follow the datasheet's NF variation with the collector
current. He ended up with KF= 5E-15 and AF= 1.13 for the 2SC3329, also
in this case the AF is greater than 1.

On Sun, Jul 19, 2015 at 4:41 PM,  ka2...@aol.com wrote:

For HF to uW oscillators  if find these modeling efforts not adequate . Only
a test circuit will show the prove...

Ulrich N1UL

In a message dated 7/19/2015 10:36:10 A.M. Eastern Daylight Time,
azelio.bori...@gmail.com writes:

For a method to extract AF and KF try this:
http://joerg-berkner.de/Fachartikel/pdf/2000_AKB_Berkner_1f_noise.pdf

see also
http://scholarcommons.usf.edu/cgi/viewcontent.cgi?article=2270context=etd
from page 55, on the parameter extraction for the BJTs

usually AF is greater than 1, as you can see in this appnote from CEL:
http://www.cel.com/pdf/appnotes/an1026.pdf

A SILVACO appnote on how to model for SPICE2 for 1/f (from page 45):
http://www.silvaco.com/content/kbase/noise_modeling.pdf

On Sun, Jul 19, 2015 at 4:59 AM, John Miles j...@miles.io wrote:

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of KA2WEU--
- via time-nuts
Sent: Saturday, July 18, 2015 3:40 PM
To: time-nuts@febo.com
Cc: akpod...@synergymwave.com; alexander.r...@rohde-schwarz.com
Subject: Re: [time-nuts] how to find low noise transistors

BFG540



That's what I mean -- both BFG540 and BFG591 have been discontinued by
NXP.  Guess they don't sell enough of them these days.

-- john, KE5FX
Miles Design LLC


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Re: [time-nuts] how to find low noise transistors

[Alex Pummer]

Also a good paper:


 Phase Noise Reduction in Microwave Oscillators

Alexander Chenakin, Phase Matrix Inc., San Jose, CA 
http://www.microwavejournal.com/authors/1981-alexander-chenakin-phase-matrix-inc-san-jose-ca



http://www.microwavejournal.com/articles/8625-phase-noise-reduction-in-microwave-oscillators?v=preview
73
Alex

On 7/19/2015 8:00 AM, Azelio Boriani wrote:

Yes, I'm with Bob Pease: the soldering iron is my best simulation
tool. Nonetheless it is useful to know how to correctly extract the
coefficients to use in the best known among the simulation tools. In
one sci.electronics.design discussion, A. Lakovlev tells to have
determined the KF based on the datasheet's NF by trials and then
adjusted AF to follow the datasheet's NF variation with the collector
current. He ended up with KF= 5E-15 and AF= 1.13 for the 2SC3329, also
in this case the AF is greater than 1.

On Sun, Jul 19, 2015 at 4:41 PM,  ka2...@aol.com wrote:

For HF to uW oscillators  if find these modeling efforts not adequate . Only
a test circuit will show the prove...

Ulrich N1UL

In a message dated 7/19/2015 10:36:10 A.M. Eastern Daylight Time,
azelio.bori...@gmail.com writes:

For a method to extract AF and KF try this:
http://joerg-berkner.de/Fachartikel/pdf/2000_AKB_Berkner_1f_noise.pdf

see also
http://scholarcommons.usf.edu/cgi/viewcontent.cgi?article=2270context=etd
from page 55, on the parameter extraction for the BJTs

usually AF is greater than 1, as you can see in this appnote from CEL:
http://www.cel.com/pdf/appnotes/an1026.pdf

A SILVACO appnote on how to model for SPICE2 for 1/f (from page 45):
http://www.silvaco.com/content/kbase/noise_modeling.pdf

On Sun, Jul 19, 2015 at 4:59 AM, John Miles j...@miles.io wrote:

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of KA2WEU--
- via time-nuts
Sent: Saturday, July 18, 2015 3:40 PM
To: time-nuts@febo.com
Cc: akpod...@synergymwave.com; alexander.r...@rohde-schwarz.com
Subject: Re: [time-nuts] how to find low noise transistors

BFG540



That's what I mean -- both BFG540 and BFG591 have been discontinued by
NXP.  Guess they don't sell enough of them these days.

-- john, KE5FX
Miles Design LLC


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Re: [time-nuts] how to find low noise transistors

[Alex Pummer]

noise figure, noise voltage, noise current: 
http://www.ti.com/lit/an/slyt094/slyt094.pdf



On 7/18/2015 2:16 AM, Attila Kinali wrote:

On Fri, 17 Jul 2015 23:25:10 -0400
Charles Steinmetz csteinm...@yandex.com wrote:


A pair of Zetex (Diodes, Inc.)
ZTX849 or FZT849 actually have significantly lower voltage noise than
either the LM394 or MAT12.

I always wonder how you figure out whether a transistor is low noise
or not. What part of the datasheet hints at which transistors have low
noise and which have not? Even if it's just try and measure, how
do you find good candidates to measure?

Attila Kinali



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Re: [time-nuts] Firmware and antenna for Stanford Research FS700

[Alex Pummer]

generally larger transistors running at much lower current than they 
inteded for have lover noise figure, but much larger input and [Cbe] and 
feedback Ccb] capacitance, the same effect could be achieved putting 
--for AC!-- low noise transistors paralell [ signal voltage adds 
arithmetically, noise voltage adds vectorial -- quadratic like power ] 
most of the case power transistors are also not so fast lower fT.


On 7/18/2015 3:16 AM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote:

On 18 July 2015 at 04:25, Charles Steinmetz csteinm...@yandex.com wrote:


Dave wrote:

  1) Do you have any suggestions for a replacement for the LM394CN, which is

obsolete and unobtainable from any reputable source? There are plenty on
eBay for a few $'s from China, but the probability of them being fakes is
greater than 0.99. The MAT12 seems to be one possible candidate for a
replacement and while not cheap, is available from reputable sources like
Farnell.


The MAT12 should certainly work, but there is *plenty* of DC degeneration
in the circuit (1v at each emitter), so there is no advantage to matched
transistors.  A pair of Zetex (Diodes, Inc.) ZTX849 or FZT849 actually have
significantly lower voltage noise than either the LM394 or MAT12.

Best regards,

Charles


Do you really mean the ZTX849? It is a power transistor (5A continuous
current collector current, 20 A peak collector current), with no
specification for noise on the data sheet. It would on the face of it
hardly seem a wise choice for a low noise amplifier, but perhaps you know
something I don't.

The LM394CN or MAT12 are at least a low-noise devices, even if the matching
between the two transistors in the package is not needed.

Dave
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Re: [time-nuts] how to find low noise transistors

[Alex Pummer]

but be sure that you have a hp4470B --a transistor noise analyzer  [ 
http://www.testequipmenthq.com/datasheets/Agilent-4470B-Datasheet.pdf ]

73
Alex

On 7/18/2015 8:47 AM, Pete Lancashire wrote:

I agree with Bob, find a vendor you can trust and make sure you buy from an
authorized distributor or if just need two or three parts try to get them
as samples.directly from the manufacturer. The reason for this is you may
get a fake or reject part and you will never know.

Trying to do the measurements yourself is pretty much out of the question
today.. Every improvement made it harder in that the equipment had to
itself be lower in noise

If interested

https://scholar.google.com/scholar?q=measuring+transistor+noisehl=enas_sdt=0as_vis=1oi=scholart





.

-pete



On Sat, Jul 18, 2015 at 5:29 AM, Bob Camp kb...@n1k.org wrote:


Hi

You have (and always have had) two basic choices:

1) Buy a very expensive part from somebody who has gone to the trouble
of characterizing the noise performance and will guarantee at least some
of what they show on the data sheet.

2) Buy a bunch of cheap transistors and test them. Lock in on a
specific part and vendor. Keep monitoring what you get in case they
“improve”
their process and the magic goes away.

How do you select candidates? That’s never been easy, there is less and
less data on the sheets every day. Normally the first step is to look at
a vendor that you have had luck with in the past. The next step is to ask
them…

Bob




On Jul 18, 2015, at 5:16 AM, Attila Kinali att...@kinali.ch wrote:

On Fri, 17 Jul 2015 23:25:10 -0400
Charles Steinmetz csteinm...@yandex.com wrote:


A pair of Zetex (Diodes, Inc.)
ZTX849 or FZT849 actually have significantly lower voltage noise than
either the LM394 or MAT12.

I always wonder how you figure out whether a transistor is low noise
or not. What part of the datasheet hints at which transistors have low
noise and which have not? Even if it's just try and measure, how
do you find good candidates to measure?

   Attila Kinali

--
I must not become metastable.
Metastability is the mind-killer.
Metastability is the little-death that brings total obliteration.
I will face my metastability.
I will permit it to pass over me and through me.
And when it has gone past I will turn the inner eye to see its path.
Where the metastability has gone there will be nothing. Only I will

remain.

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Re: [time-nuts] 10MHz Square to Sine Wave Conversion

[Alex Pummer]

Charles Wenzel has very simple but good working solution, here is :
 http://www.wenzel.com/documents/waveform.html


 On 7/17/2015 8:20 AM, Richard Solomon wrote:
I have a Mini-Circuits BLP-10.7 that I picked up at a Flea Market that 
does the job.

And no, I do not want to sell it !!

73, Dick, W1KSZ

On 7/16/2015 10:47 PM, Jason Ball wrote:
A would have thought a simple band pass filter would do the job by 
tuning

out the harmonics.

On Fri, Jul 17, 2015 at 3:49 AM, skipp Isaham via time-nuts 
time-nuts@febo.com wrote:


re: 10MHz Square to Sine Wave Conversion

The GPSDO I recently acquired outputs a 10 MHz square wave. I'd like
to convert it to a sine wave and I am looking for suggestions and 
info re
any reasonable pre-made circuits and/or boards. No sense reinventing 
the

wheel if I can avoid it.

Otherwise I will start from scratch and make a new wheel

Thank you in advance for your replies.

Regards,

skipp

skipp025 at yahoo dot com

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Re: [time-nuts] Firmware and antenna for Stanford Research FS700 Loran C frequency standard

[Alex Pummer]

MAT12 of ADI is good replacement and it is available at Mouser

http://www.mouser.com/Search/Refine.aspx?Keyword=MAT12



On 7/17/2015 1:49 PM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote:

On 16 July 2015 at 08:05, Ole Stender Nielsen ols...@mail.tele.dk wrote:


I use a home-made untuned loop antenna with 4 windings of 2.5 mm2
insulated wire on a 80 x 80 cm wooden frame, and with a grounded base
pre-amplifier mounted on the antenna frame. A schematic is enclosed for you
to copy.
The pre-amplifier is powered through the cable, and loads the FS700 input
as required.
I live about 290 km from the island of Sylt, and get nice noise margin
figures from the FS700, normally about 40 dB, often up to 46 dB.


A couple of questions

1) Do you have any suggestions for a replacement for the LM394CN, which is
obsolete and unobtainable from any reputable source? There are plenty on
eBay for a few $'s from China, but the probability of them being fakes is
greater than 0.99. The MAT12 seems to be one possible candidate for a
replacement and while not cheap, is available from reputable sources like
Farnell.

2) What is the Ca. 3 Ohm to the left of your circuit? Is that what you
estimate the input impedance is? I've got 95 m of 2.5 mm^2 wire. The
resistance of that is about 7.41 mOhm/m so my 95 m would have a DC
resistance of around  7 Ohms if I used it all.

I have built the loop 1.0 x 1.2 m. Hopefully that will be ok to receive at
least one or both of

* Lessay, France, power = 250 kW, distance = 321 km, bearing = 211 degrees.
* Anthorn, England, power =- 250 kW, distance = 419 km, bearing 331 degrees.

I now need to work out how many turns to put on it.

Dave
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Re: [time-nuts] Leap Second results: cheap GPS/1PPS receivers

[Alex Pummer]

I logged NMEA from three cheap ($15-$50) GPS/1PPS receivers, the kind 
popular with hobbyists: parallax(good), reyax(good), adafruit(bad).


what is the problem with the adafruit board?
73
KJ6UHN
Alex

On 7/1/2015 4:34 PM, Kasper Pedersen wrote:

On 07/01/2015 05:23 PM, Tom Van Baak wrote:

I logged NMEA from three cheap ($15-$50) GPS/1PPS receivers, the kind popular 
with hobbyists: parallax(good), reyax(good), adafruit(bad).




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Re: [time-nuts] Casio Watches 13 Year Drift in Seattle

[Alex Pummer]

and that magic timing machine was the vibrograph,  more abot it here: 
https://www.google.com/search?q=vibrographclient=firefox-ahs=Kyhrls=org.mozilla:en-US:officialchannel=nptbm=ischtbo=usource=univsa=Xei=iK6RVeX4FJTUoASf2KeIBQved=0CB4QsAQbiw=1024bih=507 
we had one

73
KJ6UHN

On 6/29/2015 12:16 PM, Chuck Harris wrote:

Back in the day when mechanical escapement pocket watches, and wrist
watches were state of the art, the jeweler would adjust the watch to
run at a normal rate, and give them a daily wind.  Everything looked
nice in the display case.

When a customer bought a watch, the jeweler would set the watch to
his shop clock, and instruct the customer to wear, and wind the watch
normally for two weeks, but do not set it.  At the end of the two
weeks, bring the watch back to the shop for a check up...

When the watch came back, the jeweler would calculate the number of days
the watch had been worn, note the difference from his shop clock, and
calculate the daily rate of the watch.  He would then set his timing
machine for the the inverse of that rate, and set the watch to match.

Now, when the customer wore his watch, the watch would seem to always
be right on because it was adjusted for a rate that compensated for
the customer's patterns of wearing the watch...his personal error.

This trick had an added advantage because the customer got to see
how so-so his brand new watch behaved during those two weeks, and
got to be dazzled by his jeweler's rare ability to make the new
watch perform so much better than the factory could!

If this was normal back at the turn of the 20th century, why wouldn't
Casio, and others at least do as well?  Especially now that all
electronic watches have a microprocessor built in... complete with
temperature sensing diodes, battery monitors, and other nifty gadgets.

-Chuck Harris



Bryan _ wrote:
But wouldn't normal watch wear just balance itself over time, one 
wears their
watch for say 12 hours and the rest it sits on a counter at a much 
colder
temperature. So wonder if Casio would actually go to such lengths to 
compensate.

Maybe, interesting though.

-=Bryan=-

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Re: [time-nuts] Greetings from Australia

[Alex Pummer]

Not exactly Brek, as long as the position of the two stations, which are 
in contact with each other, does not vary in the time, you don't have to 
worry about Doppler effect, also if you are trying to get in touch in 
SSB mode in the 13cm  band, you rather have a precise frequency 
reference and actually the other site should have too to find each other,
and where the Doppler  would effect your communication a special 
combination of hardware-software could provide a compensation.

73
KJ6UHN
Alex


On 6/29/2015 9:33 AM, Brek Martin wrote:

Hi Guys :)
I thought I’d say thanks for the add to the group and introduce myself.

I’m only starting to get compulsive about time and frequency.
My findings so far are that only the timing of the next second matters because 
it’s too late
to worry about the current second by the time you have the information about it.
It’s +10 hours here so I have to add 10 to everything, and that could increment 
the date,
so then a whole calendar program is required to know what the next date will be,
just because you need to know what date it will be on the next seconds tick 
that occurs.

I have a question…
Is the reason most amateur radio people care about accurate frequency mostly 
about
operating at higher radio frequencies?
I imagine if a bunch of radio enthusiasts aligned their HF radios with atomic 
standards for use
on those bands that doppler shift would ruin everything the additional hardware 
put into it.
Cheers, Brek.




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Re: [time-nuts] Close in phase noise of microwave VCOs

[Alex Pummer]

Actually a YIG, even standalone has very good phase noise performance, 
as long as the tuning current is quite, once upon the time HP made some 
cheaper version of the 856x-es spectrum analyzers [ perhaps that was the 
95xx ] they had the first LO just standing alone no PLL,  and drifted 
away, but the phase-noise performance was not so bad. These YIGs are to 
find on e-bay sometimes,

73
KJ6UHN
Alex

On 6/20/2015 6:25 AM, Jim Lux wrote:

On 6/19/15 9:30 PM, Bob Camp wrote:

Hi

One of the most interesting things about the last paper mentioned:
On Jun 19, 2015, at 8:57 PM, Charles Steinmetz 
csteinm...@yandex.com wrote:


Rick wrote:


However, a better tutorial would be the one written by
HP's Dieter Scherer which was published in Microwaves
 RF Magazine (or possibly Microwave Journal).  I believe
the same content was available from HP as an Ap Note or
something.


I suspect the paper you are referring to is:

Design Principles and Test Methods for Low Phase Noise RF and 
Microwave Sources (Scherer, 1978)


It is available on Didier's site at:

http://www.ko4bb.com/manuals/download.php?file=03_App_Notes_-_Proceedings/Scherer_Low_noise_source_design_and_test.pdf 



There are two other Scherer papers there:

Generation of Low Phase Noise Microwave Signals (Scherer, 1981)
http://www.ko4bb.com/manuals/download.php?file=03_App_Notes_-_Proceedings/Scherer_Low_PN_Signal_Generation.pdf 



The Art of Phase Noise Measurement (Scherer, 1985)
http://www.ko4bb.com/manuals/download.php?file=03_App_Notes_-_Proceedings/Scherer_Art_of_PN_measurement.pdf 




^ this one


Best regards,

Charles



is that it has a phase noise plot on an open loop microwave source 
down to 10 Hz. Not quite the VCO Jim

was looking for, but close ….




page 25 shows down to 100 Hz, Typical Free-Running Source at 10 GHz. 
Eyeballing it it looks like 20dB/decade from 10-100k, a bit more from 
1-10k, and almost 30 dB/decade from 100Hz to 1k. I wonder what the 
source was?


The SAW is definitely in the 30dB/decade bucket


This makes a good case for the 30dB/decade very close in



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Re: [time-nuts] Divider circuit for Rubidium Standard

[Alex Pummer]

once upon the time at Gigatronics we compared logic devices noise and 
found that  TTL were the quietest

73
KJ6UHN Alex


On 5/20/2015 3:15 PM, Richard (Rick) Karlquist wrote:



On 5/20/2015 11:22 AM, Magnus Danielson wrote:



The older HP counter manuals explained it very nicely too, as they
illustrated the slew-rate  amplitude noise to time-noise conversion.

What do amazes me is the fact that I've yet to see a counter input
channel which takes care to square up the signal properly, they rather
provide the comparator after the obvious damping and AC-blocking
conditioning. I can't even recall that there where much such shaping as
a side-product.


The counter front ends seem to be modeled after scope front ends
and scope triggering circuits, where you can adjust the triggering
level.  Any jitter in the triggering would normally only affect
the interpolator.  The interpolators in general were no great shakes,
so the triggering wasn't the limiting factor.



Now, remind me why ECL is lousy, I can't recall there being very high
gain in them, but fairly high bandwidth and they stay in the linear
operation region.




Magnus
___


ECL is bad because the voltage swing is low; because as you say,
a lot of the circuitry is in the active region all the time, and
because the current source in the emitters generates a lot of
noise.

In the early 1990's, I thought I had proved that the high ECL
noise was mostly common mode and that you could reduce it
20 dB by using a transformer to couple the output.  Alternately,
a good differential amplifier with high CMRR would do the trick.
I had actual measurements to back up this theory.

Subsequently, other people tried to reproduce this and could not.
By that time, I had moved on and didn't have the bandwidth to
continue to own the problem.

It would make a nice project for some time-nut to prove or disprove
my hypothesis regarding ECL.

ECL line receivers as squarers are not as bad as comparators, but
are much noisier than 74AC.

Rick Karlquist N6RK

Rick Karlquist N6RK
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Re: [time-nuts] EMI and CE certification

[Alex Pummer]

yes for transmitter  antennas, but not for receiver antennas in Austria 
Germany Switzerland France Hungary one could have receiver antenna as 
long as he want, but the height is limited similarly as in the US

73
KJ6UHN
Alex
  On 5/10/2015 7:15 AM, Chuck Harris wrote:

My recollection is that in the US, certain requirements
exist for antenna length on the so called free bands.

I have no idea what the European requirements might be,
but, perhaps they can be foiled by their allowing their
minuscule amounts of power to flow into an over length
antenna?

-Chuck Harris

Magnus Danielson wrote:
...
Depends. If they use approved frequencies and powerlevels it may be 
fine. In this
case it doesn't look like it. There are telemetry frequencies 
allocated, they should

use those.

Cheers,
Magnus
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Re: [time-nuts] TrueTime AL-AK GPS receiver help

[Alex Pummer]

I am not so sure that it is applying to that case, but there are GPS 
antenna cable  extenders which converting down the incoming GPS signal 
to frequencies at which the cable attenuation see here: 
http://www.microsemi.com/products/timing-synchronization-systems/accessories/government/l1-gps-antenna-down-up-conv

http://www.gigatest.net/symmetricom%20TTM/GPS%20%20Time%20Code%20Instrumentation/ds_gps_antenna.pdf
73
KJ6UHN Alex

On 4/30/2015 9:50 AM, Tom Van Baak wrote:

I received this email. Anyone have a good answer?
Thanks,
/tvb

--
Someone on ebay advised me to contact your website in hopes that someone in 
your organization can help me with my TrueTime model AL-AK GPS Receiver. I need 
to send it to someone so that they can check it to see if it works and can 
track Satellites.  This receiver has the onboard up/down convertor board that 
changes the receiver input frequency which is set at 4.092 MHz. I don't have 
the needed down converter at the antenna. I bought this receiver on ebay from 
someone who told me that he doesn't have the down converter as well and can't 
figure out how to get it to work at 1575.42 MHz. He also didn't know if this 
receiver can be setup for a 1575.42 MHz by removing the onboard converter and 
changing some DIP switches. If one of your members can at least check out the 
receiver at 4.092 MHz for satellite tracking That would be a big help ...
--

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[time-nuts] Fwd: Harmonics suppression in ring oscillators

[Alex Pummer]

Hi Attila, just think how all ring/delay line oscillators working: a 
status change is traveling trough a delay, and after its arrival at the 
next active component it will release a new status change, which will 
travel and arrive at the next active component, and after once it will  
get back to the begin of the loop. Basically time which required to 
travel between the active devices will determine the frequiency, and 
--as it now obvious -- the status change can not release new status 
change at the following active component before arriving to that next 
active component , therefore self the oscillator can not run at higher 
frequency that as it determinated by the delays. Of course depending on  
the wave form at the output of the system you could see many other 
spectral components

Alexander, Pummer



 Original Message 
Subject:[time-nuts] Harmonics suppression in ring oscillators
Date:   Tue, 17 Mar 2015 11:28:59 +0100
From:   Attila Kinali att...@kinali.ch
Reply-To: 	Discussion of precise time and frequency measurement 
time-nuts@febo.com

Organization:   Geist
To: 	Discussion of precise time and frequency measurement 
time-nuts@febo.com




Hi,

I stumbled over something that does not seem to be properly documented
anywhere. A ring oscillator (like any delay line oscillator) has an
infinte number of poles (on the complex plane), which are on a straight
line (disregarding the effect that the transistor acts like a first
order low pass filter, as f_t is usually a lot higher than the oscillation
frequency). This means that a ring oscillator will always excite more than
just one mode and oscillate on multiple frequencies.

While for (optical/electrical) delay line oscillators, the way to go
is to add a frequency selective element, this is not done for ring
oscillators.

So, how do people keep ring oscillators from oscillating at higher modes?

So far, my google skills have failed me to turn up any answer.

Attila Kinali

--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in the world is of no
use without that foundation.
 -- Miss Matheson, The Diamond Age, Neil Stephenson
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Re: [time-nuts] Mechanical 1PPS Oscillator Disciplining

[Alex Pummer]

yes, Ulrich's [ Rohde ] Father made  a high precision clock around 1940, 
which had an electronically tuned mechanical oscillator. The vibrating 
400Hz tuning fork is phase locked to a quartz crystal oscillator, that 
was the most precise clock at  that time, and it worked as  I have seen 
it  at the company as I worked there in the sixties of the past century.

73
KJ6UHN
Alex



On 1/9/2015 9:22 AM, Andy Bardagjy wrote:

 From a fascinating (albeit long) article about transatlantic communication 
cables

http://archive.wired.com/wired/archive/4.12/ffglass.html

On the bottom of page 45 to the top of page 46

Each piece of equipment on this tabletop is built around a motor that turns 
over at the same precise frequency. None of it would work - no device could 
communicate with any other device - unless all of those motors were spinning in 
lockstep with one another. The transmitter, regenerator/retransmitter, and printer 
all had to be in sync even though they were thousands of miles apart.

This feat is achieved by means of a collection of extremely precise analog 
machinery. The heart of the system is another polished box that contains a 
vibrating reed, electromagnetically driven, thrumming along at 30 cycles per 
second, generating the clock pulses that keep all the other machines turning 
over at the right pace. The reed is as precise as such a thing can be, but over 
time it is bound to drift and get out of sync with the other vibrating reeds in 
the other stations.

In order to control this tendency, a pair of identical pendulum clocks hang next to 
each other on the wall above. These clocks feed steady, one-second timing pulses 
into the box housing the reed. The reed, in turn, is driving a motor that is geared 
so that it should turn over at one revolution per second, generating a pulse with 
each revolution. If the frequency of the reed's vibration begins to drift, the 
motor's speed will drift along with it, and the pulse will come a bit too early or a 
bit too late. But these pulses are being compared with the steady one-second pulses 
generated by the double pendulum clock, and any difference between them is detected 
by a feedback system that can slightly speed up or slow down the vibration of the 
reed in order to correct the error. The result is a clock so steady that once one of 
them is set up in, say, London, and another is set up in, say, Cape Town, the 
machinery in those two cities will remain synched with each other indefinitely.

Does anyone know any other history about that particular piece of equipment?

Cheers!

Andy ◉ Bardagjy.com ◉ +1-404-964-1641

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Re: [time-nuts] Linear voltage regulator hints...

[Alex Pummer]

just thinking; OXCO is one ovenized crystal oscillator with temperature 
control, better to say temperature stabilizer, thus if the outside 
temperature changes the control loop shall keep the internal temperature 
constant-- by definition,
the function of the temperature control loop could be observed by the 
variation of the supply current of the oven. Also the reference voltage 
supplied from inside of the OCXO is coming from a voltage source which 
has stabilized temperature, therefore it is a relative stabil reference 
voltage source, which could be used to compare the stability of other 
voltages and thus, it could be found which voltage is moving with the 
environment's temperature.

73
Alex
On 12/12/2014 7:53 PM, d...@irtelemetrics.com wrote:

 Hi Bob,
   or 1x10^-8 per volt. If it’s a 10 MHz OCXO.
   That would be 1x10^-14 per uV
   4.7 x 10^-13 for 47 uV
  Good, so I'm not out to lunch here. ;)  Thanks for verifying those
  numbers for me!


What makes you believe that the OCXO’s temperature performance it

  not the issue?
  Because I can blow a hair dryer on it, and make very warm - almost
  hot to the touch and not see the phase or DAC change. Yet 2 degree
  thermal cycles in the room show up in the DAC and phase. I'm pretty
  sure it's not the OCXO, but if you know anything that would suggest
  otherwise, please do share.
   
   I’d guess that the analog stuff is much better than it needs to be.

  At this point I would tend to agree, but don't have hard numbers to
  know for sure yet.
   


Subject: Re: [time-nuts] Linear voltage regulator hints... -- WHY?

   Ok, so why am I harping on the “need” for all this from a system standpoint 
?
  I have no idea.
   
   1) Adding stuff to a design that does not make it measurably better

  is simply a waste of money. That’s ok if it’s your money.
  The stuff added needed to be added. It fixed an understood
  problem/limitation in the current hardware. It did make the system
  'measurably' better.
   
   2) Others read these threads and decide “maybe I need to do

  that..”. Now it’s a waste of somebody else’s money.
  If someone makes the decision to spec their part based on a somewhat
  random email, from some random thread, from an email list, they fully
  deserve the spend the extra $6 on parts. It serves them right for being
  so foolish! (Serously?!?)
   
   3) Still others look at this and decide “If I need to do that,

  I’m not even going to start”. That’s not good either.
  This isn't extremely hard, but it is challenging. Maybe someone
  wanting to build a GPSDO should know what they're getting into. If a
  10e-6/DegC scares them, you'd think coefficients of 1x10^-14 per
  uV would be worse.


4) Analysis *is* part of the design process. It should very much be

  part of this.
  It is. It's how the analog portion got to where it is now. What makes
  you think it isn't?


5) Focusing on a design aspect “because I can” is a very common

  thing. I do it all the time :) Because I fall into the trap often, I
  recognize just how much time gets soaked up on dead ends this way.
  I'm doing this because it's what I can easily contribute to the
  project. I'm spending considerable resources in terms of time and
  expenses studying and improving a piece of hardware to help a guy out,
  and to learn something along the way.


6) There are very real issues when doing this. Sorting out what’s

  real and what isn’t is far from easy. The more “noise” in with
  the signal, the less likely others are to figure out a good approach.
  Huh? Do you mean this particular response to the thread?
   
  Going back to the original post, the reason for the question was to

  look for a lower cost yet suitable replacement for the 'roll your own'
  design. One that could be shotgunned into the prototype to look for the
  thermal drift that is evident, and is not coming from the OCXO. This is
  part of the analysis you so eloquently spoke about above. As it turns
  out there are no parts that good. Moving foreword with the project, the
  COTS parts don't cut it, so at this point I see no other choice than to
  build something.

  You obviously have a lot of experience in this field. I'm glad that
  people like yourself are willing to share with the rest of us. But,
  please don't assume I'm incapable of navigating the cost vs.
  performance curve for a project, or that I'm incapable of determining
  if a part is over specified. It's insulting that you think so.
   
  Thanks,

  Dan
   
   
   
   
   
   
   

   
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Re: [time-nuts] Linear voltage regulator hints...

[Alex Pummer]

Hi, George
look for the book The art of electronics  from Paul Horowitz and 
Winfield Hill, they describe how to design excellent electronic 
circuits, including power supplies

73
Alex
On 12/11/2014 4:37 PM, xaos wrote:

I don't know if this is the right time to ask this but here goes.
I have started a design for a linear power supply for the Beagleboard

5V 5-10A. Over-Voltage, short circuit and temp protection.
Very low ripple and HF noise.

I have been watching this thread and I am still not sure
what device would give me what I want. I am not as good as
some circuit designers here, to design a PS
via discreet transistors. Dr. Bruce Griffiths comes to mind.
He would probably do this with his eyes closed.

So, I need to use a regulator chip.

The TI TPS7A4700 looks great but it can only supply 1A.

Any other candidates ?

I am sorry if I am somehow asking an obvious question.

-George




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Re: [time-nuts] Linear voltage regulator hints...

[Alex Pummer]

about linear regulators: 
http://www.analog.com/static/imported-files/tutorials/MT-087.pdf

73
Alex


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Re: [time-nuts] tcxo

[Alex Pummer]

Thermal control circuits could oscillate at very low frequencies there 
is a tricky time constant -- the heat propagation between theater and 
the temperature sensor!

73
Alex

On 12/7/2014 1:01 PM, Azelio Boriani wrote:

You can go as simple as a PTC glued on the crystal to start with.
Alternatively take a look here:
http://www.w6pql.com/crystal_oven_controller.htm




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Re: [time-nuts] Lucent KS-24361 10 Mhz out success.

[Alex Pummer]

The OCXO in the TBolt beats the Morion parts by a wide margin.

Bob 


in what way dies it?  phase noise ? harmonics? standalone frequency 
stability?

73
Alex


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

[Alex Pummer]

by us  in central California, we get 1kW/h square meter average around 
the year, the south even more, el Cajon will have today +29C° in the 
afternoon  as of 23 of November 2014

73
Alex
On 11/23/2014 9:49 AM, Poul-Henning Kamp wrote:


In message canx10hb0kdrnaayzgvm1gkduj7gklth0acdxczg894hxbus...@mail.gmail.com
, Dr. David Kirkby (Kirkby Microwave Ltd) writes:


He installs  ground source
heat pumps for the geothermal energy.  He says that they actually work
quite poorly in many cases.

There is a BIG difference between geothermal and ground heating.

Geothermal means you drill at least 50m (Iceland) or more likely
half a kilometer down, in order to harvest water at near boiling
point from the Earths geological heat-sources (mostly uranium decay).

Extracting more energy than available just means the temperature
drops temporarily.  It will increase again once you reduce the
pump rate.

Horizontal ground heat means that you are harvesting sunshine
accumulated in the top one meter of the soil.  Much of the energy
is harvested from freezing the water around the pipe thus pulling
out the relatively high melting energy of water.

If you extract more energy than you deposit sunshine, you end
up freezing a larger and larger volume of water/soil around
the pipe and your compressor will eat a lot of electricity.

In practice it looks like this:


http://ing.dk/artikel/varmepumpe-mareridt-jordslange-var-dybfrossen-i-maj-113176

(The two pictures show the same pipe, with and without frozen ground.)

Finally there is vertial ground heat where you drill down only about
40-80 meter, tapping heat mostly from ground water resources.Most
places the ground water doesn't move fast enough to deliver the amounts
of energy extracted, and over time the source returns unusably low
temperature and must be abandonned.  Typically after 25-30 years.



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Re: [time-nuts] HP 5342A (18 GHz) vs 5352B (40 GHz) frequency counters

[Alex Pummer]

I have one of the source locking EIP, which  works up to 90GHz, but 
used only for 60,xx GHz only, they are sometimes relative inexpensive 
available on e-bay, see here: 
http://www.ebay.com/itm/EIP-578-MICROWAVE-FREQUENCY-COUNTER-10Hz-TO-90GHz-INCL-SENSOR-/111503803566?pt=LH_DefaultDomain_0hash=item19f62504ae

73
Alex
On 11/21/2014 2:29 PM, paul swed wrote:

David a free opinion and thats about what its worth.
The 5342 counter was a good counter but very old now.
I used to use the 5342s for satellite work and always wanted one for home.
But given its age circa 1980 I believe, maybe it works or not at all
frequencies.
I would simply go with the 5352b because at least there is some chance to
find parts if needed.
As I say not a great answer.
Regards
Paul
WB8TSL


On Fri, Nov 21, 2014 at 4:51 PM, Dr. David Kirkby (Kirkby Microwave Ltd) 
drkir...@kirkbymicrowave.co.uk wrote:


I am looking for a microwave frequency counter and won an auction for an 18
GHz 5342A with the GPIB option today @ £200 (GBP). I have just paid for
that.

I also have the chance to get a 5352B 40 GHz counter for £500. That has
GPIB as standard.

In the short/medium term I don't see much use for a 40 GHz counter, but I
am giving consideration to buying the 40 GHz and selling the 18 GHz one.

I would be interested to know if anyone has any opinions on the relative
merrits of the two counters.

Neither of these counters have ovens,  but stability is not a major issue
given they take a 10 MHz input. That said, foes anyone know if these take
fairly common 10811A ovens? There is a chance I would use it in places
where it would not practical to feed in 10 MHz.

Dave
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Re: [time-nuts] 10MHz LTE-Lite

[Alex Pummer]

Hi Said,
do you have any information about how that TimePod 5330A works any 
principal description?

73
KJ6UHN
Alex

On 11/20/2014 2:08 PM, S. Jackson via time-nuts wrote:

Hello Mike,
  
attached is a 10MHz DIP-14 TCXO Phase Noise plot from a random  LTE-Lite

unit.
  
I had sent out a 20MHz typical phase noise plot some weeks ago, and

comparing the two they are almost perfectly 6dB apart as would be expected from
the 20log(n/m) relationship. There are variations from unit to unit of
course,  but it does not seem like one version of the board or the other has
advantages  in terms of phase noise.
  
I had also sent out a superimposed plot of the 20MHz and the divide-by-2

10MHz output of the same board at that time, and again the relationship was
almost perfectly 6dB lower at 10MHz versus 20MHz.
  
While phase noise follows theory, it does seem that the DIP14 metal shield

has a beneficial effect on the ADEV stability though. The plots we are
getting  are pretty darn good, and I want to test more boards before I post any
ADEV,  because its quite a bit better than our specification and I want to
make sure  its real.
  
The 10MHz DIP-14 boards do not have an isolating buffer like the 20MHz

boards do, on these the TCXO drives the output directly, so one must be careful
  to set the equipment to 1M Ohms input impedance or use a buffer
externally,  which is what we did to measure the attached PN plot.
  
Bye,

Said
  



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Re: [time-nuts] 10MHz LTE-Lite

[Alex Pummer]

they are affordable and good:


   585C/588C Frequency Counters

CW, pulsed, and other time-varying microwave and millimeter-wave signals 
can be automatically measured by the 585C and 588C frequency counters. 
VCO measurements, chirped radar profiling, and frequency-agile system 
analysis are all made with unparalleled ease. Pulsed signals can be 
fully characterized, including carrier frequency, frequency linearity, 
pulse width, and pulse period. The 585C measures signals up to 20 GHz 
and the 588C's range reaches 26.5 GHz with an option to extend to 170 GHz.


- See more at: 
http://www.phasematrix.net/phasematrix/products/frequency-counters/585c588c-full-rack-frequency-counters#sthash.x7L7VuWM.dpuf 




   585C/588C Frequency Counters

CW, pulsed, and other time-varying microwave and millimeter-wave signals 
can be automatically measured by the 585C and 588C frequency counters. 
VCO measurements, chirped radar profiling, and frequency-agile system 
analysis are all made with unparalleled ease. Pulsed signals can be 
fully characterized, including carrier frequency, frequency linearity, 
pulse width, and pulse period. The 585C measures signals up to 20 GHz 
and the 588C's range reaches 26.5 GHz with an option to extend to 170 GHz.


- See more at: 
http://www.phasematrix.net/phasematrix/products/frequency-counters/585c588c-full-rack-frequency-counters#sthash.x7L7VuWM.dpuf
http://www.phasematrix.net/phasematrix/products/frequency-counters/585c588c-full-rack-frequency-counters 


73
Alex
CW, pulsed, and other time-varying microwave and millimeter-wave signals 
can be automatically measured by the 585C and 588C frequency counters. 
VCO measurements, chirped radar profiling, and frequency-agile system 
analysis are all made with unparalleled ease. Pulsed signals can be 
fully characterized, including carrier frequency, frequency linearity, 
pulse width, and pulse period. The 585C measures signals up to 20 GHz 
and the 588C's range reaches 26.5 GHz with an option to extend to 170 
GHz. - See more at: 
http://www.phasematrix.net/phasematrix/products/frequency-counters/585c588c-full-rack-frequency-counters#sthash.x7L7VuWM.dpuf


On 11/20/2014 1:40 PM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote:

Said,
For a general purpose lab source, to feed things like

* 22 GHz spectrum analyzer
* 4.5 and 20 GHz signal generators
* 3 and 20 GHz VNAs
* 20 or 40 GHz frequency counter (I'm just looking to buy one)




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Re: [time-nuts] KS-24361 10 Mhz mod interesting document - older KS boxes

[Alex Pummer]

but there was a description; how to rejuvenate the rubidium bulb by 
cautiously warning it up, to remelt  the rubidium

73
Alex

On 11/20/2014 7:31 PM, paul swed wrote:

I do agree its subjective. But my gut says bad is 2-3V I know they seem to
run above 3. But whatever. When the blinkOmeter counts I am screwed. :-)
Time to get the heatgun.
Regards
Paul.

On Thu, Nov 20, 2014 at 9:07 PM, Bob Camp kb...@n1k.org wrote:




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Re: [time-nuts] Divide by five

[Alex Pummer]

check if you could get a 74AC161, which could be connected  to divide by 
5 at 125 MHz see here 
http://ecee.colorado.edu/~mcleod/pdfs/IADE/references/74AC161.pdf to be 
sure to work at 125MHz run with 5,5 to 6V...


73
Alex


On 11/7/2014 1:12 PM, Joseph Gray wrote:

I need to divide a 125 Mhz clock by five. I have looked on Mouser and every
chip I find is either obsolete or in SMT. Can anyone recommend a chip that
is fast enough and comes in DIP?

Joe Gray
W5JG
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Re: [time-nuts] Cheap Frequency chip with serial output

[Alex Pummer]

Hi Marullo

look there:   http://www.aade.com/dfd.htm almost plug and play frequency 
display for ham radio


73
KJ6UHN
Alex

Hello,
just wanted to know if there is any very cheap pre programmed pic or
something similar to get frequency of a Yaesu FT-102 radio.
I need it to know its frequency, either the VFO alone (sub 6MHz) or
possibly its real rx and tx frequency (up to 30MHz).
Using the VFO would be easier but then I will have to probe the mechanical
band commutator.
I know Arduino could be a solution, just wanted to know if something
smaller is available, possibly with rs232.
TIA

Giuseppe Marullo
IW2JWW  - JN45RQ



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Re: [time-nuts] Lucent KS-24361/Z3812A GPSDO initial setup

[Alex Pummer]

use nickel-iron battery [Edison Accumulator] which is not sensitive to 
deep discharge, over charge and last for min twenty years - 
unfortunately it does not fit into the American business model --because 
it last to long--so it is not produced in the US any more.

73
Alex
On 10/25/2014 5:30 PM, Bob Camp wrote:

Hi

Assuming the supplies are rated for a (fairy normal) 32V max, there is plenty 
of room to get everything arranged right. You *might* need to dig up a supply 
that is 28V nominal versus 24V nominal. The 10 or 15% adjust range likely will 
not quite get the 24V unit up where you would want it to be. The (say) 29V 
supply goes to one of your voting diodes and runs the unit when it’s off 
battery. The other voting diode goes to the top end of the battery stack. Your 
charger circuit puts what ever it wants on the battery to keep it happy. Yes, 
when you go on battery you loose .7 V (or less) due to the diode. If you want 
to get fancy, put a FET across the diode and eliminate the diode drop once 
everything gets going.

The bigger question is - how do you disconnect the battery after it’s done its 
thing for long enough? Deep discharge of the cells is not good for them either.

Yes this gets more complex by the minute …. where is that guy who was getting 
all preachy about keeping things simple :)…..

Bob




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Re: [time-nuts] If any of your USB devices have stopped working lately...

[Alex Pummer]

just look that:

http://zeptobars.ru/en/read/FTDI-FT232RL-real-vs-fake-supereal

73
Alex


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

[Alex Pummer]

I got two used from China, they are six years old that is the standard 
time when the whole board get replaced in a cell phone base station they 
looking like the drawing in the data sheet except pin # 6 is missing but 
it is not connected anyway they have EFC pin and it is working I tried 
it with multi turn pot and the unit's own reference, the two kept the 
relative phase on the scope in ±10° for two days relative to each other.
Does your unit has the pin -- which is not connected inside -- or the 
whole pin is missing?
I f you want to open the can get some very thin beryllium-cooper foil 
and  push it into the slot after you heated up the solder, that way you 
could separate the bottom plate and the can without doing major damage.

73
Alex

On 10/22/2014 4:57 PM, Scott Newell wrote:

At 04:20 PM 10/22/2014, Alexander Pummer wrote:

may I get some copy of that datasheet?


I don't have the correct datasheet. The seller has a catalog page, but 
it doesn't have specs for the non-EFC unit he's selling:


http://www.excesssolutions.com/cgi-bin/item/ES6542

http://www.excesssolutions.com/mas_assets/acrobat/ES6542.pdf


I have not tried opening the case to determine if the EFC could be 
restored/hacked back in.





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

[Alex Pummer]

yes Charles you are right, but you could use a trick as you derive the 
LO from the high stabile oscillator which is locked to the 
down-converted carrier the IF, and the loop is locked only if the IF and 
the LO frequencies having the correct value, but that loop change the 
feedback polarity depend on what site is the LO of the desired value, it 
needs an acquisition help and will it be not much less complicated than 
a Costas loop

73
Alex
On 9/22/2014 4:56 PM, Charles Steinmetz wrote:

Paul wrote:


One of the methods suggested for working with the wwvb psk is down
converting to a lower frequency. When experimenting with NAA I had 
built a

24 Khz receiver that down converted that signal to a 100 Hz base band.
It was a minor effort to shift it to 60 Khz by changing the LO.
   *   *   *
for 100 Hz the LO must be at 60.1 or 59.9 Khz. Or synthesize it etc.
   *   *   *
Not sure there is a real need to lock the LO at all.


I'm not sure I understand how this helps.

I thought the point of removing the PSK was to reconstitute a version 
of the original unmodulated carrier, so it can be used to discipline 
an oscillator at some convenient frequency (the PSK needs to be 
removed because it upsets the PLL phase detector). That works (in 
theory) with a TRF receiver, because the received carrier IS the tx 
carrier that is locked to a standard at the transmitter (modified by 
the propagation delay and delay variation, and then by 
doubling/squaring).  But once you convert the received frequency by 
using a LO (or BFO, whichever you want to call it), the recovered 
carrier frequency is dependent on BOTH the tx frequency AND the LO/BFO 
frequency.  You have lost the link to the tx frequency standard.


Am I misunderstanding the goal of the exercise?

Best regards,

Charles



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

[Alex Pummer]

No that is to much, except if you overdrive it and you are so lucky that 
after it broke it is still working on a different frequency, but I would 
suggest check your frequency counter too, because 3% off of a clock 
frequency wold make the clock almost unusable not just for time nuts...

73
KJ5UHN
Dr.Dipl.Ing. Alexander Pummer
PCS Consultants Pleasanton CA 94588

On 9/11/2014 3:33 PM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote:

On 26 Nov 2012 14:12, David Kirkby david.kir...@onetel.net wrote:

I've got an HP 8720D VNA. This has been out of support from Agilent
for 8 years, so its getting on a bit. There's a clock in the
instrument which keeps the date and time. This is losing about 1 day
per month (rough guess), so it has slowed by a bit over 3%.

I'm guessing this is likely to be a battery running flat, but are
there any other likely causes? I know crystal can jump in frequency,
but I'm guessing not by 3%, but perhaps if there was stress in the
crystal, it might be.

I just noticed this old post of mine. Whatever did cause it to slow about
3% no longer does. It now keeps good time - although definitely not
time-nut standard.  It probably keeps within a couple of seconds per
month,  which is good enough.

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)
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