Re: [time-nuts] WWVB cheap chip saa6579 RDS decoder back to the chip

[ehydra]

Hi Paul -

If you can spend time on that:
1. Look for the different modulation spectrum between BPSK and RDS. The 
phase modulation angle is different, the bits are manchester encoded or 
such to get a hole on the carrier frequency (For the ARI carrier), the 
baseband is DBPSK.

2. Carefully adjust the clock generator. Very sensitive to it!
3. The demodulator can lock on two different phase states. But the 
difference is just where the clock transition is positioned in the 
data-bit. In locked state this should be constant and can only change 
the next time the chip switches von search to lock state (with a 50% 
probability).
4. Yes, often such chips are interesting but poorly documented. 
Sometimes it helps to look for similar devices like the SAA6588, TDA7330 
, etc. Older datasheets often show more details.
5. I don't think you can use the chip with 1bit/sec. It is made for 
1200bits/sec. I don't know if the internal digital part of the circuit 
is fully static. But surely the capacitors of the filter are to small 
for a 1200:1 dynamic range. Maybe I misunderstood this in your application.


Have fun -
Henry


paul swed schrieb:
> Henry
> Its been a while since that thread and I have not done anything with the
> chip. But to answer your questions.
> Really good signal to noise. The modulator is 6" from the saa6579. Its a
> home brew BPSK modulator and the transitions are programmable. But I am
> following wwvbs 1sec per bit. So the phase is quite stable for long 
periods

> of time. Signal level is 1000uv but again that can be adjusted.
> Were is someone. My comment was someone on time-nuts suggested that 
you had

> to use the clock and a flip flop to properly see the data. Thats what you
> are also saying.
> As to the wwvb modulation scheme I fully understand that. But I 
actually do
> not know a lot about RDS and how it might be different from wwvbs 
method of

> transmission.
> I believe there is plenty of information on RDS. I just don't have a 
lot of

> time to figure it out.
> I will get back to the chip at some point it is really interesting 
but very

> poorly documented unfortunately.

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] WWVB cheap chip saa6579 RDS decoder back to the chip

[ehydra]

paul swed schrieb:

To the saa6579
As mentioned in the other thread.
Simple to hook up.
Cheap
Requires 1000uv or more so that ends up making things more complicated.


S/N is important, not so absolute amplitude.



But in my case simply did not really work at 57 or 60 Khz.


The chip looks for correct phase for about 50ms (max. 100ms). Did you 
check carefully that in this time-frame the phase never inversed or 
amplitude dropped down temporary?


Maybe you misunderstood the modulation scheme anyway? It is not native BPSK!



As some someone pointed out you may have to take the clock and data to a
flip flop to get the correct information.


Where is "someone"?

As I understood the datasheet you get maximum processing time (set-up 
time) for the data-bit if you use a D-FF delaying DATA strobed by CLOCK.


- Henry

--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Zero-Crossing Detector Design?

[ehydra]

Maybe, it is on my list for the university IEEE download for months.

And this is the only reference?
I have seen some similar issues in a few BPSK receiver papers. Not for 
time-nuting but for S/N.


- Henry


Magnus Danielson schrieb:

On 07/22/2012 01:39 AM, Bob Camp wrote:

HI

The Collins paper that Bruce referred to is the standard work on 
limiters / jitter / bandwidth. It can't and doesn't address all the 
possible issues in a full blown design. The math for the basic 
approach is all there though.


Indeed. It's a good and recommended read.



--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Zero-Crossing Detector Design?

[ehydra]

Interesting discussion but I must say I had several times a
brain-problem here ;-)

Am I right that for that this is in general not fully understood? Are 
there interesting papers?


I'm interested here for two points:
1. What is the right threshold for a comparator and on what it depends?
Looks like bandwidth of input signal, slew-rate of the comparator, noise
in the input signal. Maybe more.
Surely most of all people here know how to set the trigger right practical.
But what is the academic answer to this problem in the view of maximum 
S/N behind the comparator?



2. What if this is a if-strip amp with interstage filters. Maybe in the
look of a BPSK receiver. So we can connect to time-nuts GPS interests 
back ;-)




Recall that the jitter of a trigger point is noise divided by
slew-rate.


Is it possible to expand here the explanation? Any reference?

Thanks!

- Henry


Magnus Danielson schrieb:

You can view the schmitt trigger detector as having a state, and when
in proximity of the trigger point, you let the noise control when the
 trigger point occurs.



Schmitt trigger is a nice tool, but it can do you great harm if you
do not understand what it does help you with and what it doesn't help
you with.

You need to gain yourself to slew-rates where a schmitt trigger would
do no harm, and when you are there it will do essentially no good
either, as you are looking at a high slew-rate square signal.

So, you *can* do better than a Schmitt trigger. A schmitt trigger can
be sufficiently good. A schmitt trigger can work well if you have
filtering in front of it to significantly reduce unwanted systematic
noise.




--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Zero-Crossing Detector Design?

[ehydra]

On the Bruce page there is a table with increasing stage amplification 
from low-level to the output.
If this is the optimum for low jitter how does it connect to the 
well-known rf design philosophy to have the highest amplification at the 
first stage, not the last stage, to have maximum S/N ?


Any idea?

- Henry


Chris Hoffman, KG6O schrieb:

Thank you, Bruce!!! That is exactly the information I was looking for. I 
sincerely appreciate the help.

-CH

On Jul 19, 2012, at 12:47, Bruce Griffiths  wrote:


The problem of optimal zero crossing detector design was essentially solved by 
Oliver Collins in the 1990's.
Essentially a series of cascaded limiter stages with appropriate gain and 
bandwidth distribution are used.
With a 10MHz 1V rms signal only 2-3 stages suffices.
However unless you need fs jitter less complex zero crossing detectors should 
suffice.

1) a comparator (or line receiver) based design should achieve sub 10ps jitter.

2) AC coupling to the input of a CMOS (AC04, AHC04 LVC04) should achieve a 
jitter of 1ps or less

3) A simple differential pair with AC coupled emitters (reduces asymmetry due 
to component tolerances ) is capable of sub ps jitter.

There is a spreadsheet to assist design of Collins style zero crossing 
detectors at:

http://www.ko4bb.com/~bruce/ZeroCrossingDetectors.html 



___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] disciplining sound card

[ehydra]

Demian Martin schrieb:
>If you don't want a delta sigma ADC you can substitute a different 
kind >but

>there will be tradeouts. Usually bit depth vs sample rate vs. accuracy.

Any market overview available?



A simple way to discipline a 22.5792 and a 24.576 VCXO to a 10 MHz reference
would be very interesting. 


I suggest one of the Cirrus audio clock PLLs.

- Henry


--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Widdershins

[ehydra]

Jim Lux schrieb:
widdershins derives from Middle low german weddersines from Middle High 
German widersinnes, wider=back + sinnes=in the direction of


"widersinnig" means 'nonsense' = not useful in the common thinking.

The german "wider-" means 'against something'. There is another german 
word "wieder-" (more lengthy pronounced) which means 'repeated' or 
'repeat something'.


A common mistake in german language is writing "Wiederstand" meaning 
resistor. The correct is "Widerstand" = forces against something (here 
the physical current). The "-stand" has the same meaning as in english.



Another interesting word is Windows coming from german Windloch or 
Windauge. A hole in the wall to let the smoke out or fresh air in in 
ancient time were the buildings of poor people did not have any window 
other than the door to come in and a outlet for the fire on the top. So 
a window (without glass) was still an improvement. Later they used wood 
on the windows and considerable later had glass windows. In the 
beginning very small glass pieces without great color control during 
manufacturing. Each batch of glass had a different color! Something 
still in use at churchs for beautifulness. The old german word for this 
is Butzenglas.
I suspect that M$ didn't resolved that word before using it or was it a 
easter-egg?


That for fun ;-) Well, is history not directly per definition a time-nut 
issue?


- Henry

--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Widdershins

[ehydra]

Bill Hawkins schrieb:

Around 1530, it was considered very bad luck to walk around a church
widdershins (see the Wikipedia article). I think it goes back earlier
than that, to a time well before clocks.


They wrote at Wiki:
"Because the sun played a highly important role in primitive religion, ..."

Funny use of "primitive" when thinking of that almost all known life 
forms get the energy from the energy differences between the hot sun and 
the cold space around.



- Henry

--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Paper about DCF77 performance

[ehydra]

Hm. Is the paper now online or do I have to add it to my list of 
downloads at next university trip?


Thanks -
Henry


Hal Murray schrieb:

enge...@alumni.ethz.ch said:
Building the best DCF77 receiver in the world :-) 


You have found the right place.  :)





--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Paper about DCF77 performance

[ehydra]

Would be interesting if I can read it.

As far as I know even the IEEE grants the right to the author of his 
paper to locate it on his own web-site for public download.


Thanks -
Henry


paul schrieb:

On 6/13/2012 3:46 PM, Daniel Engeler wrote:

Hi,

This is my first post to this mailing list. I wrote a paper about the
German longwave time transmitter DCF77 which you may find interesting.
Here is the link, unfortunately I am not allowed to post the full PDF:

http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=6202411




Daniel
Might be a great read for us time-nuts. Unfortunately we have no access 
to the ieee site so it will go unread and appreciated.

Regards
Paul



--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

[time-nuts] Impedance measurement fitting algorithm

[ehydra]

Hi time-nuts!

If I remember correctly here was a discussion about an older HP 
impedance measurement equipment. The one which is able to calculate a 6 
ideal parts replacement circuit for the measured passive device.


How does is it works? I would like to fit parts for simulation in SPICE. 
So I need something like a algorithm to fit for minimum error a input 
table with complex numbers (frequency-sweep) to this 6 part circuit. For 
example the universal capacitor component in LTspice is able to hold RLC 
and even XTAL data and more like residual current for electrolytics.


Any ideas?

Thanks -
Henry

--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] WWVB phase plots

[ehydra]

Hm. I had a quick look at http://en.wikipedia.org/wiki/WWVB
I cannot see why it won't work with the DCF77 scheme. The carrier is
always on-air. Do I miss something? To low bandwidth of the transmitting
antenna?

Sorry, I didn't followed the thread in whole.

- Henry


Brooke Clarke schrieb:

Hi Henry:

There are millions of WWVB clocks in use and the new signal must be 
fully compatible with them.




--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] DIY GPS/GLONASS project

[ehydra]

Yes, his whole site is interesting stuff.

But the GPS was already mentioned here :-)
Even the Andrews variant.

- Henry


Tom Van Baak schrieb:

While researching Geraldo's GLONASS question I ran across
an amazing set of pages. It's the best documented homemade
GPS+GLONASS receiver project I've ever seen. Although it's
somewhat old (mid 1990's) the text makes a wonderful tutorial
on GPS even if you have no plans to ever build it.

http://lea.hamradio.si/~s53mv/navsats/theory.html




--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] WWVB phase plots

[ehydra]

What makes me wonder: Why don't they adapt the DCF77 implementation? Is 
it the not invented here syndrome?


At it looks like they never heard of Kasami sequences.


- Henry


Dennis Ferguson schrieb:

On 18 Mar, 2012, at 10:52 , John Seamons wrote:

They do talk about using the 11-bit Barker code for autocorrelation. But the 
sync bits transmitted only match the Barker code if you interpret them a little 
bit out-of-order.


The part of the paper that talked about the Barker code confused me
somewhat since I couldn't quite figure out how it was relevant.  The
autocorrelation property of the Barker code is only interesting if
the Barker code is the only thing being sent (over and over), but
in this case the concerns are more about spurious correlations with
the variable data, something for which no solution seems to be
possible.




--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

[ehydra]

gary schrieb:
Just meditating out loud, if you were to go push pull with a ferrite 
antenna AND you are winding it yourself, you could avoid the biasing 
resistors by putting a center tap in the antenna itself, then tie that 
center tap to an appropriate bias voltage. I haven't seen this done, so 
their may be a gotcha with that scheme, but the science is good. 


Works with SA602. A russian web-site shows differential turns on a 
ferrite rod. 



Generally you will get a lower noise circuit if the input device is an 
amplifier rather than a buffer.


Yep.




Lanksford's input stage is essentially a push pull buffer, but I don't 
see that cancelling 2nd harmonics like a push pull amp. But for a whip, 
which is a single ended input, I don't see a way to get a differential 
input. Not true for a ferrite antenna.


You can transformer couple the input. Then the whip is at DC and it is 
possible to let DC-current to ground. 


- Henry


--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

[ehydra]

I wonder because ALL of the shown circuits in his pdf are AC-coupled.
It is maybe possible to servo-loop with OpAmps but surely not worth the 
effort.


Useful too as a Scope FET-probe.


- Henry


Poul-Henning Kamp schrieb:
> In message <4f65d971.8070...@arcor.de>, ehydra writes:
>
>> 
http://home.earthlink.net/~christrask/Complementary%20Push-Pull%20Amplifiers.pdf

>>> In my implementation, it covered DC to 200MHz until I low-pass'ed it.
>> His designs are always a good source but this one is AC-coupled ;-)
>
> Not in my implementation, I have eliminated the input capacitor because
> the active element is 3cm from the PCB, and I drive the output with
> a centertapped transformer.
>
>

--
ehydra.dyndns.info


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

[ehydra]

Poul-Henning Kamp schrieb:
> In message <4f64f279.4040...@arcor.de>, ehydra writes:
>> Marek Peca schrieb:
>
>>> This was almost the only reason for ferrite rod -- simplicity and
>>> attenuation of TVs, some LCDs, 50Hz etc.
>> If you make the antenna about 10x bigger you can omit the whole 
ferrite.

>
> I have used two antennas, an unloade air-coil, actually plastic-lid-coil:
>
>http://phk.freebsd.dk/loran-c/Antenna/

Yeah. I remember the red.

The degaussing coil of old TVs can work. Some resonate at 50KHz which is 
a little low but it depends on the manufacturer. So try it.



>
> and a vertical monopole based on a Chris Trask design I can highly
> recommend:
>
> 
http://home.earthlink.net/~christrask/Complementary%20Push-Pull%20Amplifiers.pdf

>
> In my implementation, it covered DC to 200MHz until I low-pass'ed it.
>

His designs are always a good source but this one is AC-coupled ;-)

A CD4069 is all one needs for first experiments. I was satisfied.


- Henry

--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

[ehydra]

No, there is a geometric saturation. You can't use the better
permeability in reality.

The optimum length to width relation is about 6 to 10 for ferrite rods.
Here is a diagram:
http://ehydra.dyndns.info/NG/time-nuts/Pettengill%20002.jpg


This is one of the classics in my link list:
http://www.bentongue.com/xtalset/29MxQFL/29MxQFL.html


- Henry


li...@lazygranch.com schrieb:

Wouldn't the difference be directly proportional to the relative
permeability? If so, the difference would be more like 125, not 10,
depending on core material.


--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

[ehydra]

In the end every antenna receives the EM wave! The EM-wave is the far
field. The antenna works in the near field where a dominant component
can be the E or M. That depends on the antenna. Between the near and the
far field the field is "converted" and local Z0 highly complicated.

As far as I know every antenna declared as whole EM-capable wasn't it
and I think it is maybe just impossible to couple directly EM to a
antenna .


The ferrite antenna couples the M component. The vertical capacitive
antenna the E component!
Both can be resonant or broadband.

The ferrite antenna is highly nonlinear and therefor not suitable as
transmitter. As we don't have a "reverse" component for FETs this is
even true for the vertical capacitive antenna.

And a wire antenna in the classical way is a M component antenna. No
ferrites and low Z0 means it can be effectivly used as a transmitting
device.

- Henry


li...@lazygranch.com schrieb:
The ferrite loop antenna receives the magnetic portion of the EM wave. It doesn't have to be a bandpass LC filter. 

The Wellbrook loop antennas are one example of a broadband antenna that receives the magnetic portion. 



--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

[ehydra]

Marek Peca schrieb:
This was almost the only reason for ferrite rod -- simplicity and 
attenuation of TVs, some LCDs, 50Hz etc.


If you make the antenna about 10x bigger you can omit the whole ferrite. 
The only benefit of a ferrite loaded coil is the size of it!
In ancient time radios had flat air coils like spider webs. In fact they 
are named after spiders in german.

This air coil can be resonated too!

I can imagine a resonated vertical antenna. Never seen that but all it 
requires is a low impedance pre-amp stage and a loading coil of very high Q.


- Henry

--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Temex LPFRS-01

[ehydra]

You must understand the difference between deionized and destillated 
water! I think often they sell deionized water of poor quality as 
destillated on gas stations etc. Much like "destillated" as a general 
synonym for "the best water".


If all fails, simple rain water is very good. Wait for a heavy rain and 
throw the first litres because of salts and other ingredients coming 
from your roof. Then get the water you want. Discretes can be removed by 
a coffee filtre.


Or buy it at a chemicals supplier.

Testing can be done with a resistance meter if you carefully control the 
mechanical parameters of your two metalic plates.



I wonder that you can still buy TCE. I thought it is banned in EU. I 
know that is a wonderful cleaning product.



- Henry


Azelio Boriani schrieb:

Yes, correct. The problem is that I have no deionized water nor a suitable
oven. The use of the tetrachloroethylene has simplified the procedure for
me (after all I was refunded, should the Rb fail it is not a money loss).
Anyway I'll try to locate a supply for high quality deionized water, the
oven can be built... I have one item to process more carefully.


--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

[ehydra]

Hi Marek -

I don't know where you are in CZ. I'm on the boarder in DE near PL and 
CZ. The distance to DCF77 is about 450km and if I check the amplitude 
across 24h I see considerable very deep fading effects! I think it is 
useless as a phase-coupled time receiver. At least in specific 
positions. It will loose phase at least for twice the day for approx. 2h 
! That was the report for a ferrite rod.


The other way would be a high-impedance FET-preamp vertical-wire 
antenna. I think this will resist much more fading effects. But it is 
unchecked at the moment. You're welcome to do it.


The benefit of a resonated ferrite rod is the good bandpass filtering 
for local interferers like TV. The FET vertical wire will need heavily 
filtering thereafter. All in the whole dynamice range, of course.



Ferrites can be temperature controlled. They have big spreads in 
parameters anyway! The production procedure is explained in the 
classical book about Ferrites: Snelling "Soft Ferrites".



- Henry


Marek Peca schrieb:

That would be 36ns group delay variation if I did the math correctly.


OK

And in article P. Hetzel: Time dissemination via the LF transmitter 
DCF77 using a pseudo-random phase-shift keying of the carrier, 2nd EFTF 
Neuchatel, 1988., they conclude with timing results of about 2..10e-6 s 
RMS over ~1000km distance.


However, I do not know what is the reality and whether such a 
performance is limited by atmosphere/ground conditions, or whether it 
could be better within LF band.


However, what material are you using for the ferrite? The material can 
have a significant tempco.


In my project, I have used noname rod taken from within DCF77 alarm clock.
If I will recreate it, I will look for something defined at the store.



--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] broadband MPX signal stereo

[ehydra]

Demian Martin schrieb:

I have tested a number of soundcards and while the EMU 2020 has issues
(serious jitter and noise from the USB interface) I can recommend the ESI
Juli@ as having flat response and good SNR up to 90 KHz. It's a PCI card, no
USB. I have measured the performance of FM MPX adapters and tested FM
Transmitter performance with one. You get 24 bit at 192 X 2 continuously as
long as you want. With some simple pre-filtering and gain you should be able
to get some 60 KHz signal at very low levels. With a deep FFT I get to -130
dBFS easily. With the demo board for the AKM AK5345a I am getting better
than -160dBFS. That has SPDIF out. Depending on the filter selection, most
chips have a flat option, there is no significant phase shift up to
frequencies close to the cutoff.


Interesting. From time to time I consider to make my own card.

Where can I find this demo card you mentioned?




I have tried and dumped a number of other sound cards that were dead ends.
The ESI Juli@ is usually around $120. 


As far as I heard the ESI is a little better than the EMU0202.

- Henry


--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] broadband MPX signal stereo

[ehydra]

I own a EMU0202 and when I use it with my laptop running on battery I 
can see in spectrum lab FFT the DCF77 at 77.5KHz and the GB time-code 
transmitter at 60KHz easily. The antenna is 1 meter of wire. Not bad for 
100 bucks. I'm around 450km from DCF77 and maybe 800km from GB transmitter.


If I connect the laptop SMPS then I see the spread-spectrum clock for 
the SMSPS controller wrappling around 50-60KHz.
In fact I can see almost all here in the house. If someone activates his 
TV I see the 15625Hz PAL line frequency coming out of bottom noise.



On the Maxim web-site is a AppNote for using a sound-card as a sampling 
head.


- Henry


Azelio Boriani schrieb:

Interesting the ESI sound card, I'll check where to buy one. Useful to
sample VLF time and frequency signals directly.




--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Xtendwave

[ehydra]

At least in the USA one can "patent pending" even the neigboor's cat.
It looks in Germany we go now the same way. About 100 years ago one has 
to be shown a functional device for patenting it. I think this was a 
really good idea.


- Henry


Chuck Harris schrieb:

I was of the understanding that SBIR's results are in
the public domain that however, doesn't mean that
a patented receiver that uses the SBIR results cannot
be had.

You too can use the results of this SBIR and patent
your receiver's special features.



--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] broadband MPX signal stereo

[ehydra]

Azelio Boriani schrieb:

Yes, there is people who have what in the past was expensive test equipment
and now can be bought by 1/10 of the original price. The problem is that
you need someone who can record 2 seconds of a signal that is slightly
beyond the actual sound card sampling capability. A signal that you can
have by simply tuning your radio and hooking directly to the FM
discriminator output. This signal is available virtually all over the
world. AFAIK there was in the past no expensive test equipment that can
sample and record a file. Now there are: the R&S SMBV100 can sample and
play any signal upto 3GHz with the full options fitted and the companion
recorder/player for 200K euros, the file produced are not PC compatible, of
course.


"the file produced are not PC compatible, of course."

As usually ;-)

A wave-file can have a sample frequency of 32bits integer. So the 
maximum is around 4GHz. And 32 integer or float for the amplitude. And 
several channels. All in the standard. Enough for even big priced DSOs.



I will suggest this device for christmas to my beloved other side :-)
Has it the right WAF?

- Henry

--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] broadband MPX signal stereo

[ehydra]

I heard a broadband sound-card like EMU0202 should work.

I asked because of the various people on the list with expensive test
equipment one should be able to record a good sample.

Looks there is no interest.

- Henry


Azelio Boriani schrieb:

Are you sure that a .WAV file can support the full MPX stereo and RDS
signal? I suspect that you need raw samples that a sound card can't handle.
The output of a FM stereo and RDS radio discriminator are beyond the usual
audio bandwidth. The output of the discriminator full bandwidth is first
used by the RDS decoder and then (partially filtered) by the stereo deMPX
and then by the audio processor.

On Thu, Mar 15, 2012 at 2:08 AM, ehydra  wrote:


Hi!

I'm looking for a sampled wave-file from a radio receiver MPX-signal
including the RDS frequency band around 57KHz. I searched the Net but found
just nothing that worked.

So I ask here. Maybe someone has the possibility to sample a couple of
seconds.


--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

[time-nuts] broadband MPX signal stereo

[ehydra]

Hi!

I'm looking for a sampled wave-file from a radio receiver MPX-signal 
including the RDS frequency band around 57KHz. I searched the Net but 
found just nothing that worked.


So I ask here. Maybe someone has the possibility to sample a couple of 
seconds.


Thank you all!
- Henry

--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Tele Quarz Group OCXO

[ehydra]

Looks like one can open it without problems.

- Henry


Detlef Twesten schrieb:

Hi,
does someone know the TQTC 16-01A from Tele Quarz Group?
I'd like to get the Pinout and the supply voltage to help an radio 
amateur in Germany.
He tried it with 5V and the standard pinout, pin 3 supply, pin 4 output 
and pin 5 ground, but it doesn't work.
view from above 
 

bottom view 
 



--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] How best to exchange Large files?

[ehydra]

Thanks David and all the others!

- Henry


--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] How best to exchange Large files?

[ehydra]

Robert Darlington schrieb:

Typically you can resume ftp transfers with the "reget" command.  It
has to be implemented on the server.



Interesting.



There are tons of file sharing services on the web that are free.  Why
go back to the 1980s?


Because the problem is to send the whole file at once! The download is 
not the problem.


- Henry

--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] How best to exchange Large files?

[ehydra]

David schrieb:

I used Bittorrent last time to do this because of the ease and
reliability factor.  There is no resuming since it does not work that
way and the whole process was just set and forget.  HTTP and FTP can
usually resume aborted transfers as well but require explicit support
from both sides and in practice, we had problems with corruption. With
a file download service, the problem would have been resuming aborted
uploads.



I'm a little confused. Does utorrent can work in a private mode? So I 
send a magnet link to the consumer and he can connect to my utorrent 
client? Does utorrent work as a server?


Looks to me that there are different torrent protocols? I never 
investigated it.


If it works it looks like the simplest way.

- Henry

--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] How best to exchange Large files?

[ehydra]

I think most users have ADSL, where the problem is the low upload 
bandwidth. If the connection drops, the whole file is lost.


The download is much faster and so there is a good change to save the 
whole file.

If not:
If the web-browser and the file-owning server understand reconect, one 
can retry the download and then the old file merges with the new part 
without further effort.


So I wonder if FTP does it the same way? Any experience?


My problem is that I want to send a big file to another person, but my 
internet upload bandwidth is way to small.


Any suggestions? I run a web-server with PHP and a FTP-server.

As I learned from the thread a torrent-app is not enough. Transfering 
via POP3 looks impossible because seldom the two email-server will have 
both account limitations beyond 100MB.


cheers -
Henry


David J Taylor schrieb:

Hi:

I've used:
https://www.yousendit.com/
with no problems.

Have Fun,

Brooke Clarke


.. but the limit on that service has changed from 100 MB down to 50 MB, 
making it rather less useful to me.


Cheers,
David


--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] mixers for frequency measurement

[ehydra]

Magnus Danielson schrieb:

On 01/19/2012 09:31 PM, Don Latham wrote:

Oh dear I had the wrong idea. Thought PIN's were designed for switching.
There is a breed of "ultra-fast" diode for protection in MOSFET
switching circuits like h-bridges. Any better?




Interesting idea! If it works, it is new as I didn't found something 
with Google:

"UPSC200" spice mixer


I'll replace the PIN diodes in our optical receivers at work, obviously 
they can't handle the gigabits we pass through them.




LTspice have a model for the "UPSC600".

- Henry

--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Simple Super Ripple Eater

[ehydra]

Here is a hand-corrected version:
http://ehydra.dyndns.info/NG/time-nuts/Simple%20power%20supply%20ripple%20rejection%20for%20battery%20systems.zip

- Henry

John Lofgren schrieb:

There have been discussions in the past about ways to reduce regulator output 
noise or clean-up oscillator or voltage reference power supplies.  Here's an 
article from Design Ideas in Electronic Design that looks promising.  It has 
pretty decent rejection even at 1 Hz.

http://electronicdesign.com/article/power/Simple-Super-Ripple-Eater-Also-Cleans-Battery-Based-Supply.aspx

Note that the figures don't display properly (at least in Firefox) with 
anything but the embedded links in the text.


--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] New unit of time measurement

[ehydra]

d.sei...@comcast.net schrieb:

could write tickets when you had enough hits on your car... Worst
offenders? BMW and Audi drivers...


Here in Germany too. The worst drivers are the ones with license plates 
beginning with "LB-" AND driving Audi or BMW.

LB means Ludwigsburg - a city near Stuttgart.

Stuttgart -> Porsches. Curiosly they drive seldom such fast as BMW and 
Audi on small streets here.


Looks like BMW and Audi drivers need to rise money all the way whereas 
Porsche drivers have money already enough.


An arabic saying:
Only the poor man have to run his way.


- Henry

--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] New unit of time measurement

[ehydra]

In Germany hand-used phones during drive are banned for several years 
now. I think it makes sense. Well, humanoids should think on it DIY but 
the reality is another.


In China I've seen down-counting LED displays for the red sign. But this 
is just to simple for Europe. Badly.


- Henry


Mark J. Blair schrieb:

Article states: "Upon arriving at a red light, drivers apply the brakes, pick up 
their mobile devices, and begin reading and sending e-mails. The signal to resume driving 
comes not from the green light but from some motorist in the back tapping politely on the 
horn."


This is why I begin honking immediately after stopping. It removes the latency, 
which can otherwise be annoying at a light with a short green cycle. :-)





--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Generell help on search web-objects. was: OT: Need datasheets on photomultiplier tubes

[ehydra]

Rex schrieb:
You might want to join this Yahoo group where the question would be more 
on-topic...

http://tech.groups.yahoo.com/group/GeigerCounterEnthusiasts

The Photonis site is one of those flashy-looking places where you can 
only find useful information if someone has already told you where it 
is. No functional search or guide pages that I could detect.


This site has a useful big list with some simple descriptions, but 
thanks to Photonis, many links to Photonis pages get 404...

http://www.lastek.com.au/content/view/179/1051/

On the Photonis pages, most of the docs are found in...
http://www.photonis.com/upload/industryscience/pdf/pmt/

But its contents can't be viewed. Put pdf names (listed below) at the 
end of the above for the full link.


This helps pasted in Google:
site:http://www.photonis.com/upload/industryscience/pdf/pmt/

if there a cross-links memorized.

Or try:
link:http://www.photonis.com/upload/industryscience/pdf/pmt/

and the last resource:
www.photonis.com/upload/industryscience/pdf/pmt/

Further one can shorten links from right, correct links or try archive.org

The last try is to shorten the link from _left_ ! This finds copies of
files on another site.


- Henry


--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] crunching numbers from XOR phase detector

[ehydra]

The XOR phase comparator is without feed-back and that simply means no 
dead-zone. This is consistent with literature on XOR PDs.


It will of course have non-linearity which is improving with speed of 
the process technology. A 74HC4046 will be better than a CD4046.
BUT the low-frequency noise is inversely proportional to channel-length 
of the used MOSFETs. So for time-nuts interests a slower CD4046 can be 
better.


The other 4046 phase comparators are made of flip-flops where the 
dead-zone is proportional to gate-delay.


For ultimate performance one have to use a classical DRM.

- Henry


Brian Justin schrieb:

Not yet, but I guess I will now!
Thanks!

-Brian





- Original Message 
From: Orin Eman 
To: Discussion of precise time and frequency measurement 
Sent: Wed, January 4, 2012 12:59:12 PM
Subject: Re: [time-nuts] crunching numbers from XOR phase detector

Have you tried the 74HCT9046?  They claim no dead zone.  Note - seems to be
HCT only.

Orin.

On Wed, Jan 4, 2012 at 9:32 AM, Brian Justin  wrote:


Be very careful of the FPD in the 4046. It has a dead-zone when the phase
error
is at or very close to zero.  Some versions of the chip claim to have
"improved"
that dead-zone. But it's still there to some degree, at least in all the
versions I have tried.

-Brian, WA1ZMS



--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] FE-5680A clock shaping (sine -> square wave)

[ehydra]

David schrieb:

I could analyze it on SPICE but I suspect the real world construction
parasitics will be what limits the performance.  I just sketched it
out in my notebook but I will see if I can post it somewhere.  Is
there a quick and dirty online schematic capture site?


Scan it. I will make a LTspice file.




It is not that complicated being a differential amplifier driving
complementary pair of emitter followers, a pair of voltage clamps, and
then a pair of complementary current mirrors configured as
transconductance amplifiers.


I want to SEE it including all circuit parameters. Thank you.




When you say symmetry limiting do you mean to prevent second harmonic
distortion like for driving a mixer?  I was thinking of this more for
driving a single ended transmission line cleanly while maximizing the
edge rates and minimizing jitter.  Duty cycle correction could be
added pretty easily.


Hm. I think second harmonic distortion looks very much like intentional 
symmetric waveform in the first instance. The fun begins if we decide to 
look for equal time distance or equal power for both phases. Interesting.





The circuit you linked is going to have a little problem since both
the 2N5769 and the 2N5770 are NPN and the circuit requires a pair of
PNPs.  Other than that it looks perfect for driving a high level
mixer.


As far as I know driving a mixer was the circuit intention. I SPICEd it 
with BFR93 types. The circuit has a high reflection coefficient, 
unfortunately. Maybe this is unavoidable and we need a diplexer.


Yes, looks like an typo for having 4 NPNs there. I will clarify this 
with Chris Trask. Thanks.






Here is another limiter circuit (by Chris Trask):
http://ehydra.dyndns.info/NG/LTspice/Negative%20Impedance%20LO%20Driver.pdf


- Henry

--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] FE-5680A clock shaping (sine -> square wave)

[ehydra]

Is it possible to sketch the circuit? I can SPICE it.

Symmetry limiting is the holy grail and it is questionable if a discrete 
design is way better than one of the chips.



Here is another limiter circuit (by Chris Trask):
http://ehydra.dyndns.info/NG/LTspice/Negative%20Impedance%20LO%20Driver.pdf


- Henry


David schrieb:

What kind of performance would you expect in this application?  Low
jitter?  50 ohm output?  TTL or better signal levels?  Fast rise and
fall times?  Duty cycle correction?

After reading your post I was thinking about how to go about it and
ended up with an 8 transistor discrete design using a differential
amplifier input and pair of current mirror transconductance amplifiers
for the output.  I have been looking into designing a pulse generator
for oscilloscope calibration and have an interest in GPSDOs so maybe I
will prototype this as well just to see what kind of performance a
bunch of 2N3904 and 2N4401 jelly bean transistors can provide.

On Thu, 29 Dec 2011 21:14:30 -0800, John Beale 
wrote:

In case it's useful... there are many ways to get a square wave out from a 
sine wave in, but one straightforward way is with a comparator. Some work 
better than others. The slow ones won't work at all at 10 MHz, and the very 
fast comparators (MAX999, ADCMP600, LT1116 etc.) are more expensive, and 
perhaps harder to work with. I tried a MAX9013 in SO-8 package and it works 
well for the job. You can see my schematic, circuit and scope plots at the 
bottom of this page:



--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] DGPS@home

[ehydra]

Hi Hal -

Thanks for your efforts!

I just settled down my GPS for the car on my desk (under a brick roof) 
and left it over night alone. Between evening and morning I wrote 4 
locations on paper and later dumped it into Google. So this is a test 
case for ONE unit. It is a TomTom equipped with a SIRF3 chipset. Yes I 
know this is not a statistical proven example ;-)


It shows 3 locations within 7 meters. One jumped away.

Here it is fully interactive:
http://ehydra.dyndns.info/NG/time-nuts/DGPS/GoogleMaps-Route.html

Download the file and open it LOCALLY in your Web-Browser. As far as I 
figure out how Google-Maps work, then you don't need a site-key from 
Google. Otherwise you can get a new key at Google.


The same as static picture:
http://ehydra.dyndns.info/NG/time-nuts/DGPS/Google-Route.jpg

Not so bad.

Maybe a SIRF4 will even better?


- Henry




Hal Murray schrieb:

If you do a test, let us know your findings.


I think the answer will depend upon how good the location is.  If the 
limitation is ionosphere delays, two units near each other should have 
similar errors.  If the limitation is multipath, being near each other 
probably won't help much.


---

This was a good excuse to make some graphs.

I have lots of data.  Most of it is from units that are indoors and barely 
work.  Not surprisingly, the location data is far from good.


Conveniently, I had a pair of units next to each other and grabbed all the 
NMEA data for over a month.  I took a random day.  One of the units had 74777 
valid samples, the other had 32439.  There were 28651 seconds that had good 
data from both units.  I wrote some hack software to merge the data on the 
seconds that overlapped then plotted the difference in lat/lon.


I've seen samples off by miles. Yes, not many samples but a few.  :)  Data 
collection may need another filter: don't treat a sample as "good" unless the 
previous few samples were good.  Remember, this is a crappy location.


Quick summary for those who don't like graphs, if you ignore anything off by 
more than 20 feet in either lat or lon, it's a random number generator.


Here is the same data with different vertical scales:
  http://www.megapathdsl.net/~hmurray/robot/diff.png
  http://www.megapathdsl.net/~hmurray/robot/diff-1000.png
  http://www.megapathdsl.net/~hmurray/robot/diff-20.png

Maybe I'll get a chance to collect some data outside in a reasonable location...




--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Help with TCXO

[ehydra]

Sorry. Read:
"Or use a line-receiver if the oscillators is buffered internal."

- Henry


Michael Malloy schrieb:

its a shame i cannot post the picture i took is there any way to be
able to send my oscilloscope picture its 800k thats the problem


--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Help with TCXO

[ehydra]

A 50K picture should fit the problem.

I successfully use 4000 series for amplifying a 5MHz PSK signal. The 
HEF4x is a little faster than HCFx.


Or use a line-receiver if the oscillators is not buffered internal.

- Henry


Michael Malloy schrieb:

its a shame i cannot post the picture i took is there any way to be
able to send my oscilloscope picture its 800k thats the problem


--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Help with TCXO

[ehydra]

Maybe the HC04 oscillates but the experimenter doesn't see it. Or 
misunderstood that ICs have to be seen from top, not bottom like 
transistors.


It is better to use an HCU04. Even a 4069UB should work at 8MHz@5V. I 
would prefer 100K feedback and several stages AC-coupled.


The 5V is nominal, so use 5V not 4,9V. But it is not important for your 
problem.


- Henry


Attila Kinali schrieb:

On Mon, 28 Nov 2011 16:15:37 +1100
Michael Malloy  wrote:


Hi all I ordered a 8.192MHZ TCXO 1.0PPM
Now it was supposed to have a clipped sine wave output? however it
looks more like a saw tooth, I assumed a clipped sine would be a sine
wave with the peaks clipped, I am running this through
a 150pF cap and then using a inverter amplifier i.e. 74HC04 with a 1M
resistor from input to output.

am I over loading or loading down the the oscillator, or should I be
changing the buffer capacitor?
I mean the circuit is working but its not 45/55 duty cycle
the out put looks like the first 0 -90 degrees of a sine wave then
drops to zero stays there for about 20% of the duty cycle then ramps
back up?


Do you measure the TCXO raw, w/o any circuitry attached?
Because this sounds rather like that the 74ZHC04 is messing
with the signal. Maybe the 1M resistor isnt really 1M?

Other than that, i would feed the output directly to
a 74HC14 (schmitt trigger input) to square it. If you
want to have precise or adjustable duty cycle, you can also
use a comparator (but make sure to include enough hysteresis,
otherwise the comparator might oscillate)


Attila Kinali



--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Low noise power supplies - dont' use Electrolytics

[ehydra]

I molt them in a high-power charge-pump. The same with WIMA MKS.

At normal usage they will last forever and work even at low temperature 
whereas normal Al caps won't.


- Henry


gary schrieb:
At sane temperatures, OSCONs are very good. Who runs their gear hot 
enough to boil water?

http://edc.sanyo.com/pdf/e_oscon.pdf


--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] DGPS@home

[ehydra]

I read that for position accuracy ionospheric effects are the main 
source for typical single frequency receivers. So looking for DOP would 
be not helpful because the ionospheric way is for two 'relative' on the 
same position located teceivers vs. satellites position almost the same 
and that would cancel this error source out!? The end-effect should be 
better values than seen in the datasheet.


I must ask again. More opinions?

- Henry



Azelio Boriani schrieb:

Usually GPS receivers have DOP figures you can use to estimate the position
precision. Maybe worth using timing receivers for position to increase the
position accuracy.

On Thu, Nov 24, 2011 at 1:01 PM, ehydra  wrote:


Hi all!

I wonder what would be reasonable location accuracy if two cheap same type
GPS modules will be several meters apart? I understand that it involves
statistical numbers.

Any idea? Say for a small robot.

Thanks!
- Henry


--
ehydra.dyndns.info


--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] SDR GPS

[ehydra]

Pricey, but allows to fly on high-attitude/speed. The region where money 
ist not so important ;-)


- Henry


Poul-Henning Kamp schrieb:

Has any of you played with this:

http://www.sparkfun.com/products/8238



--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

[time-nuts] DGPS@home

[ehydra]

Hi all!

I wonder what would be reasonable location accuracy if two cheap same 
type GPS modules will be several meters apart? I understand that it 
involves statistical numbers.


Any idea? Say for a small robot.

Thanks!
- Henry


--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Low noise power supplies for time nuts circuitry

[ehydra]

li...@lazygranch.com schrieb:
The bozos at Broadcom have actually patented using shunt regulation in their chips. Good luck enforcing that patent. 


Must be a joke or misunderstanding.

Look for example in the datasheet of TCA440. A really old IC. In the 
internal circuit displayed is a diode shunt regulator serving at the 
same time as reference divider.


- Henry

--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] [FS] 70MHz Vectron OCXO units

[ehydra]

Hi Peter -

I sent you an off-list message but got no response.

Please contact me.

Thanks -
Henry


Peter Loron schrieb:

Hello, folks. I have several new-looking Vectron OCXO units. They output a 
70MHz sine wave. Vectron wouldn't give me the data sheet for them, but I do 
have the pinout.

If you are interested, please contact me off list. Thanks.

-Pete
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.



___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] DCF77 question

[ehydra]

asma...@fc.up.pt schrieb:

QUOTE:

"DCF77 marks seconds by reducing carrier power
for an interval beginning on the second".

UNQUOTE

This is not a good (Heaviside step) time marker.


The amplitude is carefully crafted to signal and transmit antenna.




Is it possible to decode that signal by any very
simple "on-my-shelf gear", as for instance a PC
sound card,to recover a good seconds time mark?

Do you know some software to perform the above task?



You need a wide-band sound-card like EMU0202 and SpectrumLab. This 
software contains the needed tracking software. A simple JFET or 
low-noise OpAmp as preamplifier for a 1 metres wire-antenna.



Go to Yahoo-groups:
SpectrumLabUsers
VLF_Group


- Henry


--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Sine to LVDS

[ehydra]

He he. For me Key West Florida is a synonym for status 'retired for fun' 
or because career end (because already earned enough money for the rest 
of life).


- Henry

Jim Lux schrieb:

However, another search does turn up:
Oliver Collins, who now lives in Key West, Florida, ...

So maybe he'd be more than happy to talk about hard limiter design 
instead of his recent academic career..



--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Sine to LVDS

[ehydra]

Thanks Magnus!

I have no access to IEEE papers.

I read Bruce' pages already.

- Henry


Magnus Danielson schrieb:

Oh, do read the Oliver Collins "The Design of Low Jitter Hard Limiters"
IEEE transactions on Communications, Vol 44 No 5, May 1996 pp 601-608

Toss in this paper:
http://www.unusualresearch.com/AppNotes/TimeNuts/OptDualMixer.pdf

Bruce has been studying this a bit more than me:
http://www.ko4bb.com/~bruce/ZeroCrossingDetectors.html

Bruce has taken the basic analysis from Collins and adapated it to a 
more reasonable situation where you change op-amps from 
low-noise/low-bandwidth op-amps to somewhat higher noise but much higher 
bandwidth op-amps.


--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Sine to LVDS

[ehydra]

Hi!

I'm reading on, so sorry for replying soon.

Magnus, what is the next good paper?

cheers -
Henry


Magnus Danielson schrieb:
This paper is however only scratches the surface on bandwidth/gain 
analysis in balancing the added noise (per step) and added slew-rate 
gain (per step).



--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Sine to LVDS

[ehydra]

Hi Bruce -

Do you have a reference to read on for this?

Thanks -
Henry


Bruce Griffiths schrieb:
Sub picosecond jitter is feasible if one cascades a series of low pass 
filtered limiter stages.


--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] DDS'ery narrow scoped.

[ehydra]

Your algorithm looks very much like the solution to the problem how to 
find divider values in a rf receiver having a very low IF and *not* full 
length divider chains for dividing all the needed reference frequencies.


So how to find two values connected.


Interesting.

- Henry

--
ehydra.dyndns.info


Magnus Danielson schrieb:
As I was tired I did not disclose enough details for implementation, but 
selected to be brief to bring in the approach to see if it was "obvious" 
or not.


OK.

A typical phase accumulator of n bits have N = 2^n possible states.

> ...


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] DDS'ery narrow scoped.

[ehydra]

That is maybe interesting to you:
http://www.holmea.demon.co.uk/Projects.htm#Frac

- Henry

--
ehydra.dyndns.info


Luis Cupido schrieb:

P.S. At the moment I'm testing on the bench with a real FPGA cyclone III
with a 48bit dds at 100MHz fclock and at circa 6 and 18MHz output and it 
is not that bad. I got better than -60dBc in the desired ranges.

So not too unhappy for a start ;-) PLL cleans 99% of it...
but the close in spurs are annoying.


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Low noise power supply recommendations

[ehydra]

There get slower with falling current.

- Henry


--
ehydra.dyndns.info



Hal Murray schrieb:

I was thinking about trying an orange or yellow LED here, and dimming the
LED with the series resistor, trying to make it as dim as the neon bulb, but
I don't know if a LED can be dimmed down that low.


LEDs work fine at low output levels.  At low current, the light output is 
linear with current.  It falls off at high current and/or high temperature.






___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Advanced 5 to 10 MHz doubler

[ehydra]

paul swed schrieb:


Other comment injection locking is always interesting to me because you can
inject at quite low frequencies. I would like to see some of the details
from Henry.


Here is a cut of a bigger circuit. Generates 10MHz from disturbed 10MHz 
like a PSK transmitter. Or if you remove the D-FF you have 20MHz.


http://ehydra.dyndns.info/NG/time-nuts/SyncOsc_1.gif

Some values may need a little tuning because the original circuit uses 5MHz.

Welcome discussion.

- Henry


--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Advanced 5 to 10 MHz doubler

[ehydra]

Almost lost...

OK. In the meantime I worked on a project where I needed a doubled 
frequency of a signal with gaps. I made a synchronous oscillator locking 
on the double frequency. Works great and is as simple as thing can go.


It works by injection locking. Such a circuits shows a PLL 
characteristic, but is entirely forward directed. And simpler.


- Henry


--
ehydra.dyndns.info


paul swed schrieb:

Lets see feb to june. Time to restart this thread.
I found this a very interesting thread and finally ordered the transformers
from mini circuits. Needed some other parts and had enough of an order to
make sense.
I do plan to build the circuit and try some of the comments suggested to see
what happens.
Though this may take a bit of time. Lots of other things to work on.
Regards
Paul



___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] GPS interference and history...

[ehydra]

Thanks Jim!

Sorry for posting on time-nuts list with time-offset +1 ;-) corrected.

- Henry


--
ehydra.dyndns.info



Jim Lux schrieb:

On 6/10/11 6:55 AM, ehydra wrote:

Jim Lux schrieb:

The MEO height of GPS was a deliberate choice (again, that GPSWorld
series is a fascinating history of how it came about). Don't forget
that one of the original reasons for GPS was for doing midcourse
correction on ICBMs.


Where is this GPSWorld history located?



___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] GPS interference and history...

[ehydra]

Jim Lux schrieb:
The MEO height of GPS was a deliberate choice  (again, that GPSWorld 
series is a fascinating history of how it came about).  Don't forget 
that one of the original reasons for GPS was for doing midcourse 
correction on ICBMs.


Where is this GPSWorld history located?

regard -
Henry

--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] GPS interference and history...

[ehydra]

GPS receivers work with very different IF concepts! There is no common 
frequency at all.


- Henry

--
ehydra.dyndns.info


Burt I. Weiner schrieb:
For many years the FCC has not allowed FM broadcast stations within 
certain distances of each other where a 10.7 MHz frequency difference 
existed.  Not exactly the same thing, but did show an understanding of 
what can go wrong as a result of good receiver front end selectivity.  
In AM and FM broadcasting there has also been required distances between 
1st and 2nd adjacent channels, only partially because of overload issues 
but more so because of occupied bandwidth and overlapping.  I'm not sure 
how much more it would cost to build GPS receivers with better front 
ends, but I'm sure it would've priced GPS devices out of the hands of 
many consumer level users.  The FCC under the direction of Congress has 
made (allowed) some pretty stupid moves in the past bunch of years.  In 
my opinion, the FCC has forgotten what their purpose is, and being run 
by attorneys has made the situation that much worse as there are very 
few attorneys that understand the un-revocable physics of the 
electromagnetic spectrum.





___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] IEEE Spectrum Magazine interviews one of our own...

[ehydra]

That is the solution:
http://xkcd.com/162/

- Henry


--
ehydra.dyndns.info


Tom Van Baak schrieb:

Hi Christopher,

Thanks for those interesting links.

Note PHK's original ACM article is:

The recent IEEE mention is:
 


With audio:
 


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] cheap 5V OCXO in 14DIP has about 1E-9 drift per day

[ehydra]

I prophet:

Chris Albertson schrieb:

I asked the question because I might want to build one of there but I
could not see how they could be table with just an RC filter.  So the
answer is "they just are".


Mixing generates two frequencies and a DC phase shift response.
If RC filtered you get the lower of both frequencies.




OK, so they are stable but why would it run at 10+16=26 and not 10.01+15.99=29

And what happens if I want to build a 10.01 reference clock?  Could I
do that with a regenerative filter?



Is have a natural tendency to lock to the lowest n/m ratio.


- Henry

--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] SI Unit Problems

[ehydra]

It makes senses even for this list!

Numbers like 12 and 60 are chosen for their high number of dividers.
That is a mathematical reason. Think of in ancient time all was divided
in equal integers units. Even the Maya knew it!

This is connected to numbers of low n-divide with the ultimate of prime
numbers. If you're there you find reasons for encryption and low-spur
PLLs. Then you're on on-topic again ;-)

- Henry


--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] SI Unit Problems

[ehydra]

I don't think that SI is the last system we see and that is for the 
decimal system too.
I see small problems like the definiton of mass as units of 1000xgrams 
and that the k is low but should be K to be consistent (M, G, etc).


But to think the american system is better must be a joke. Even the 
japanese changes all 40 years ago.


S/N is now almost at -infinitum.

- Henry


--
ehydra.dyndns.info


Don Latham schrieb:

I agree. After all, teh SI system is clearly God's units as revealed by
the French...
Don

Wolfgang

...probably somebody who hates SI units for some unknown reason and uses
his intelligence to construct a couple of ridiculous "arguments" supposed
to show that this system of units had holes.

On Tuesday 05 April 2011, Brooke Clarke wrote:

// This means that, if you follow the rules of the SI,
// 1 Hz = 1/s = 1 radian/s which is simply inconsistent and violates
basic


Why exactly should hat arise when "following the rules of SI"?

If I follow this guy's rule, I could also argue:
1 Hz = radians Hz = radians^2 Hz = radians^3726 Hz.
Similarly, 1 s = radians s = 1 radians s.

That's independent of the definition of Hz and seconds and can be
constructed
whenever you can replace numerical "1" with something else.

Where's the point? What links radians to seconds?

But hey, guys, sshhh... don't tell this guy that you could also write
Hz = s^-1 because then he'd start with 1 Hz = "seconds to the power of
a negataive radiant" which clearly shows that SI units are utterly
perverse!

Wolfgang, DL1SKY


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] SI Unit Problems

[ehydra]

For me it looks like this guy hates SI system. There are many out there. 
How cares?


The problems arise if systems get mixed up and at least one end of the 
communication link thinks the other does the same.


So left-right screws confusing between UK and Europe, satellites with 
inch-meters trouble etc.


- Henry

--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Datum Handbook of Time Code Formats

[ehydra]

or djvu:
http://any2djvu.djvuzone.org/djvu/110312/84.181.76.205/19469.110312152109.djvu

- Henry


--
ehydra.dyndns.info




Rob Kimberley schrieb:

I've also just downloaded the "slow version" in 2.5 minutes. Seems damn
quick to me. This was with Firefox, which I prefer above all other browsers.

Rob Kimberley


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Plot phase noise spectrum from DMTD

[ehydra]

At the moment I design a Ethernet UDP-capable sound-card as a secondary 
priority project in free-time.
I settled to the AD7641 but welcome any suggestions/additions if one is 
interested.

The main app would be SpectrumLab.

cheers -
Henry

--
ehydra.dyndns.info


Tijd Dingen schrieb:

For that kind of sampling rate you may want to consider the ADS1258EVM.
At 46 euro it's a pretty good deal IMO. I've been using it for some time
now and I really like it. Got mine from Mouser...

http://mouser.com/ProductDetail/Texas-Instruments/ADS1258EVM/?qs=sGAEpiMZZMtEG0FVrTlw%252bpXY5pUeT3h5vjrb5nJbBSc%3d

http://focus.ti.com/docs/toolsw/folders/print/ads1258evm.html

You can also get the PDK if you want to go for the extra DSP board.
Personally I found the price difference a bit too much so went for the
plain EVM. But maybe if you want a DSP board to tinker with as well it
might make sense. Although in that case I'd go for the ADS1278EVM-PDK
for best bang for buck...



___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Datum Handbook of Time Code Formats

[ehydra]

All IE6 users pay YOU with time for nothing. Thanks!

- Henry


--
ehydra.dyndns.info



gandal...@aol.com schrieb:
In a message dated 12/03/2011 15:23:39 GMT Standard Time, ehy...@arcor.de  
writes:


Yes  Graham.

But we are intelligent, or?

Use a torrent.

Or a  friendly hoster like bplaced.net

- Henry
-


Oh Henry
 
I don't use torrents, I don't know bplaced, I actually PAY for the  
"privilege" of providing these files via Rapidshare so obviously don't do  
intelligent, but despite all this over 80 copies have now been  downloaded.
 
I can live with that:-)
 
regards
 
Nigel

GM8PZR


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Datum Handbook of Time Code Formats

[ehydra]

Yes Graham.

But we are intelligent, or?

Use a torrent.


Or a friendly hoster like bplaced.net

- Henry


--
ehydra.dyndns.info



gandal...@aol.com schrieb:
I'm sorry to hear you continued to have problems and  do not know quite 
where you ended up.


As others have pointed out,  Rapidshare, along with all the other so called 
"free" file hosting sites do  their best to persuade downloaders to use 
their paid services. Rapidshare and  most others do this by imposing time 
delays for single downloads and increasing  time penalties for multiple 
downloads. Some go further and seem to randomly lock  out downloaders claiming 
they've failed too many "capthchas" or whatever, again  intended to cause enough 
irritatiation that potential users just pay and be done  with it.




___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Datum Handbook of Time Code Formats

[ehydra]

Try this direct link:
http://rs670tl.rapidshare.com/cgi-bin/rsapi.cgi?sub=download&editparentlocation=0&bin=1&fileid=452123988&filename=Handbook_of_Time_Code_Formats.pdf&dlauth=A984216200E0480149FFCA297C92059F7FA1E43DD52079D0BE699B7F88C8F8072C90141D76C0EE983CACD23800836FC429CFC37CD2376012BF0A8F640A0915345B03ADC8EA17E4179EA90333499ECD74A6B444EA75E7A8A08F1442EE16B9A8E25413BBD4A6C02A93394D7F9A2DEB8B0F#!download|670l34|452123988|Handbook_of_Time_Code_Formats.pdf|26241

Maybe you must remove a time-dependent sub-URL after several time.


- Henry


--
ehydra.dyndns.info


J. Forster schrieb:

I just tried it and got the same thing. Rapidshare used to work for me,
but not any more.

-John


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Plot phase noise spectrum from DMTD measurement?

[ehydra]

John Miles schrieb:

Sound cards will usually end up running within 1 Hz of the desired sampling
rate, but it's important to pick a sampling rate that's native to the
hardware, or the driver will resample the data.  On Windows, many drivers
for popular sound cards rely on some imprecise resampling code that
apparently was distributed by Microsoft in the DDK.  Stick with 44100 or
48000 Hz, or you'll be lucky to land within a few dozen Hz in some cases.



One can this circumvent by using ASIO driver or a wrapper like asio4all. 
This removed the frequency resampling distortion and at the same time 
the low-pass filtering above 20KHz for my sound-card.




Warren's been getting some really nice ADEV plots from a tight PLL sampled
with a USB sound card, running a quick and dirty command-line utility I put
together to acquire the data and downsample it.  I'll post the next build on
my web page if anyone else is interested in playing with it.



Where?

- Henry


--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] 50/60 Hz clocks

[ehydra]

The exclusive solution feasible is:
http://shop-emea.u-blox.com/abashop?s=274&p=productdetail&sku=553
Nice, as you can program it for PPS at 10KHz or some other frequency.

More cheap, not so spectacular:
Cirrus CS2000 PLL
Locks on 50Hz or more


- Henry

--
ehydra.dyndns.info


Cezary Rozluski schrieb:
Let us suppose I have Thunderbolt (I really have one)  as a 
time/frequency source, but any other time-nuts recognized frequency 
source should by sufficient for the fun to drive old 50/60Hz stuff with 
the highest precision available (and for fun, comparable to 
www.leapsecond.com  solution, modulo cesium/hydrogen clock).  It would 
be very nice to see correction for leap seconds as well :-) :-)


Regards,

Cezary




___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Plot phase noise spectrum from DMTD measurement?

[ehydra]

S/N drops spectacular!

Any probs to cut the noise-floor here? The text looks like art.


- Henry


--
ehydra.dyndns.info



Bruce Griffiths schrieb:

Stephan Sandenbergh wrote:

Thanks,

I'm familiar with the designs you posted to measure voltage noise ect. on
you home page. These, with some modification, mainly removing the 
blocking

caps, seems that it would do the trick.

Cheers,

Stephan.

On 10 March 2011 10:50, Bruce Griffiths  
wrote:


  
For conventional phase noise measurements at offsets in the (10Hz, 
20kHz)

range one can use a sound card with a low noise preaamp.
Suitable sound card preamps with lower noise floors than Enrico's or
Wenzel's designs can be built using readily available components.
Wider bandwidths ( up to 1MHz or so) are not difficult to achieve.

Bruce


Stephan Sandenbergh wrote:



Hi,

Cross-correlation a very clever idea! Thanks for the reference - 
Rubiola

got
some good sources of reference on his home page.

One thing though - for a phase-noise kit one will probably need to 
replace
the ZCD with a low-noise amplification stage of around 80dB to be to 
allow

sampling at ADC voltage levels?

Cheers,

Stephan.

On 8 March 2011 22:28, Magnus Danielson
  wrote:



  

On 03/08/2011 07:46 PM, Stephan Sandenbergh wrote:





Hi,

I recently noticed something interesting: The DMTD measurement 
gives a

set
of phase values x(t). From which fractional frequency y(t) is
calculable.
So
now it seems viable to plot the spectrum, Sy(f) and if you scale it
properly
you arrive at Sphi(f). If I'm  not making a gross error somewhere the
math
seems to check out. But, I'm wondering is there a physical reason why
this
isn't valid?

I have not seen this being done anywhere - so I assume there is.
However,
it
seems possible to plot Sphi(f) for 1Hz

Re: [time-nuts] difference between Oncore M12 and M12+T (useful when buying online)

[ehydra]

This is an alternative:
http://shop-emea.u-blox.com/abashop?s=274&p=productdetail&sku=553

Nice, as you can program it for PPS at 10KHz or some other frequency.

- Henry

--
ehydra.dyndns.info


Rick Hambly (W2GPS) schrieb:
Every now and then I see e-mails like these. I would like to remind everyone that Synergy Systems, the USA distributor for the M12 series receivers, offers Ham Radio and Educational (time nuts) users a new M12M with the precision time firmware and an on board battery for only $59.18 with the 10% Ham/Edu discount (sown from $65.75). This unit also includes both Motorola binary and NMEA message formats. 


Synergy can be found at www.synergy-gps.com or at (858) 566-0666. They have 
been very good to the Ham and educational communities for many years.

Rick
W2GPS



___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Low noise power supply

[ehydra]

Hi John and group -

For us germans, american magazines always look overloaded with 
advertisments. The marketenders don't like to hear that the generations 
under 40-50 are mostly advertisment blind just by natural adaption.
The times where I read paper electronics are long gone. The Internet 
completely took over. Sometimes I go for wooden pdfs in the local 
university library.


But back to the interesting subject - that I personally not fully 
resolved so there is a need of discussion!

Here is a first insight:
http://waltjung.org/PDFs/Sources_101_P2.pdf

In general: LDO is bad. low Iq is bad too.

cheers -
Henry


--
ehydra.dyndns.info


J. Forster schrieb:

Electronic Products is not a real engineering publication. It is a forum
purely for new product releases. Always has been.

Articles there are almost always written by applications engineers for the
product being touted.

I got it free for decades, and threw the magazine away at once, unread.

Why, you ask? Simple, the EEM...  Electronic Engineers' Master, the giant,
multi-volume industry directory with company names and phone numbers,
about the size of a cinder block... came free, with a subscription.

Best,

-John



___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Low noise power supply

[ehydra]

For me, this looks like a advertisement campaign only. Not very 
sophisticated or ingenious. Read that you don't need LC-filters at the 
output because of the LDOs. *lol* If the designer ever heard of corner 
frequency??

And the ISL9000A is the same.


- Henry

--
ehydra.dyndns.info


David C. Partridge schrieb:
H I wasn't impressed.  The 'scope screen shot of noise levels on the outputs used 20mV/division, and the thickness of the regulated traces told us precisely nothing.  Now if the author had measured 20uV noise over a BW of 10Hz to 100kHz (about 63nV/rtHz), or 3uV over the same BW (about 10nV/rtHz), I'd have started to get interested.  

However as no claims were made, I took the title of "Ultra-Low Noise" with a large shovel of salt.   



Regards,
David Partridge


-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf 
Of ewkeh...@aol.com
Sent: 08 March 2011 21:41
To: time-nuts@febo.com
Subject: [time-nuts] Low noise power supply

There is an interesting article in the March 2011 Electronic Products magazine 
"design an ultra low noise supply for analog circuits. It is a combination of 
switcher and LDO's and written by P Hunter TI so it may also  be available on their 
site.
Bert Kehren
___
time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to 
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.



___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Low noise power supply

[ehydra]

If one can say that the actual noise-floor signal is approx. white noise 
than the peak to average is a factor of 6 to 7 on a analog scope. I once 
read this somewhere and found it not a so bad decision.



- Henry

--
ehydra.dyndns.info



David C. Partridge schrieb:
H I wasn't impressed.  The 'scope screen shot of noise levels on the outputs used 20mV/division, and the thickness of the regulated traces told us precisely nothing.  Now if the author had measured 20uV noise over a BW of 10Hz to 100kHz (about 63nV/rtHz), or 3uV over the same BW (about 10nV/rtHz), I'd have started to get interested.  

However as no claims were made, I took the title of "Ultra-Low Noise" with a large shovel of salt.   



Regards,
David Partridge


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Spacecraft Timekeeping

[ehydra]

There are is a list on a ballooner website with GPS devices working 
beyond export rules.



- Henry

--
ehydra.dyndns.info



Magnus Danielson schrieb:
First thing to consider is that standard GPSes will not meet your needs, 
since they have to obey the height and speed limits for export rules.


The side-effect is that doppler frequencies may be much higher and both 
tracking and acquisition needs to include these more extremer doppler 
frequencies.


Use of PTP within a rocket or spacecraft may or may not be a good thing. 
NMEA + PPS may suffice and be less power-hungry. IRIG may also be an 
option.


If timing and frequency needs strict correlation with ground, relativity 
comes into play due to altitude alone shifts frequency.


Cheers,
Magnus




___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Low noise power supply

[ehydra]

Here:
http://www2.electronicproducts.com/Designing_an_ultra_low_noise_supply_for_analog_circuits-article-fapo_TI_mar2011-html.aspx

- Henry

--
ehydra.dyndns.info


ewkeh...@aol.com schrieb:
There is an interesting article in the March 2011 Electronic Products  
magazine "design an ultra low noise supply for analog circuits. It is a  
combination of switcher and LDO's and written by P Hunter TI so it may also  be 
available on their site.
Bert Kehren 


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] PN sequence generation using GPS

[ehydra]

Spread-spectrum and similar schmes were a little kind of secret and 
secure communication around 1970 where the mathematics where done in the 
years before, beginning with the classic Shannon paper about information 
theory. Many papers were classified to help protect the knowledge their.


Especially for the military it was interesting because the average 
knowledge level was low for this and the machinery to crack the code on 
air was way more expensive the average bad 'terroris't would effort.


As it became common to have FFT-based receiver equipment 'for cheap' 
this doctrine wen't useless. Useless the same as thinking atomic bombs 
will secure freedom.


If one looks in the spectrum in a very fine granular structure the data 
transferred by SS will be seen on every single spread-code bit!! All 
needed is a high-enough S/N and a lot of computing power. On the analog 
side the receiver must be very strong signal capable so other 
'intruders' will not be mixed-in in the wanted signal.


A FFT ist nothing more than an integration on every small frequency step.


- Henry


scmcgr...@gmail.com schrieb:

Hi Chuck,

Serious contesters have directional antennas and most of the new contest quality rigs have FFT spectrum displays and the ability to record several Mhz of spectrum directly to disk for later analysis.   


   The old stereotype of unsophsticated home brewed gear is now a subculture of 
the Ham community.

These are the guys who will hear you and FIND you esp since most of these guys have north of 50k invested in their stations and anything which interferes with getting that last elusive multiplier will be tracked to the end of the earth. 


 and some of them like me are also time-nuts.


Sent from my Verizon Wireless BlackBerry

-Original Message-
From: Chuck Harris 
Sender: time-nuts-boun...@febo.com
Date: Fri, 25 Feb 2011 13:16:13 
To: Discussion of precise time and frequency measurement

Reply-To: Discussion of precise time and frequency measurement

Subject: Re: [time-nuts] PN sequence generation using GPS

I guess that is why I mentioned something about doing it competently.

The FCC so seriously winged the methods usable by hams as to render them
effectively useless.

A nice direct sequence spread spectrum system with a couple of MHz
spread would be well below the background noise of any narrow band
receiver.  Sure, you could find it with a wide band detector if you were
close by, but how would you know that you weren't looking at some other
anomaly, like a bad insulator, or trash coming off of fluorescent lamps?

Done correctly, you could run spread spectrum just about anywhere you wanted
to, and remain undetected.  Using direct sequence, you would be so low in
power density that it could easily be argued that you were operating within
the constraints of a part 15 device's leakage.





--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] VCXO help

[ehydra]

Hm. Concerning the CS2x00. Is there a PC software available to program 
it via i2c? I mean without this IDT monster software.


Any hint is welcome!

- Henry



ewkeh...@aol.com schrieb:


Thanks for the info Fred
The problem is the  package. Looking at the Cirrus Logic CS 2300-CP and 
use  
a  bubbler. Since I start out with 5 or 10 MHz there must be something 
out  

there  that can be soldered.


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] VCXO help

[ehydra]

A circuit design? Look for 96MHz variants. Many out there.
Example:
http://www.qsl.net/dk1ag/96mhz_e.pdf


- Henry

--
ehydra.dyndns.info


ewkeh...@aol.com schrieb:
As part of the D/M project the counter uses a 100 MHz VCO with an AD 4001  
PLL. To simplify further I would like to consider a very simple VCXO, easily 
 available components, no tuning, any ideas out there. For once phase noise 
is of  no concern.

Bert Kehren


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] power spectrum of hard limiter output

[ehydra]

I rethinked the problem after reading several papers.


OK. We have an if-strip. To avoid spectral regrowth in later stages 
because of saturation, the input must be  amplitude 
controlled. Pulses and bursts at the input will saturate somewhere in 
the stages. An common AGC is always design-limited by solving for speed 
AND compression at the same time.


Now, looking at the spectrum of a click - the same as a pulse. For 
example cw transmitted by amateur radio morse. How to avoid the annoying 
band splitter? One possibility is to shape the amplitude response in 
time for the pulse by tanh function. This will 'compress' the spectrum.


A differential transistor stage realizes a tanh function.

A CMOS inverter is in effect the same. One of the transistors of the 
differential stage is 'inverted'.


So I think a CMOS inverter already realizes an realistic and simple 
pulse shaper for pulses in an if-strip.



I tested different ideas with schottky-diodes somewhere in the if-strip. 
In the end, I must say that leaving such out of the design is simply the 
best.



Any comments?


- Henry


ehydra schrieb:

Hi Magnus -

Well. I made homework for sure. Endless viewed websites what others had 
done.
We all seek for the singularity of beauty in our art. At the moment this 
is a CD4007 or similar without AGC. Cheap, effective. Not oversized. I 
came from TCA440. One of the not many receiver chips where the IF is at 
one output reachable. Then I found I must increase carrier frequency 
beyound 30MHz. So the integrated mixer entered useless. I used an 
external device. Next I found that the integrated IF-strip is not one of 
the quiets... Remembering several statements about using CMOS inverters 
in s.e.d. for analog reasons, the way was clear...


Implementing an AGC makes the design much more complicated. Can 
oscillate etc.


Going without AGC seems a reasonable way if the modulation is one of the 
phase modulation systems where amplitude is not very important.


Then look how big is the dynamic range of a simple CMOS inverter.

Meanwhile I found two examples made by others. So the way looks not to 
idiotic ;-)


- Henry


Magnus Danielson schrieb:

I find it more and more curious a working concept not to find in the
I-net. I'm looking several weeks. Maybe wrong keywords.


Well, have you considered what an AGC might do for you?
It has been the traditional way of reducing the effect of signal level 
on phase-detector gain and hence on the loop gain. The hard-limiter 
text is to be seen in this context where the SNR steers the 
compression factor, i.e. change of loop gain.


Cheers,
Magnus


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to 
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts

and follow the instructions there.



--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Random Walk Noise experiment

[ehydra]

I think the confusion is now perfect:
http://www.mikrocontroller.net/topic/207061#2059725

Let Google translate it from german to your language.

Does the difference come from voltage vs. power spectrum?

Magnus Danielson schrieb:

On 12/02/11 21:02, Bruce Griffiths wrote:

Flicker noise is not the same as random walk noise, the spectra differ.
Using an AC coupled generator (eg a sound card) filters out the low
frequency content.

Zeners and transistors (biased at low current) can be used to generate
flicker noise directly at least for low frequencies where it dominates.
Generating random walk noise is more difficult, integrating white noise
is one technique that can be used (at least in principle).


Of course... *head-slapp*

white noise has a flat power spectrum
flicker noise has a power spectrum of slope f^-1
random walk noise has a power spectrum of slope f^-2

For random walk you need to do integration. If you do it in analogue, 
care in low-frequency cut-off comes in and below it you will have white 
noise. For digital it's a trivial, but you may end up with digital 
wrap-around but doing a low-frequency leakage you avoid it and end up 
with the same situation as in the analogue domain.


So expect there to be a frequency limit for it if synthesized.

Cheers,
Magnus


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

[time-nuts] Random Walk Noise experiment

[ehydra]

Hi all!

I friend of mine wants to construct an experiment for students for 
studying random walk noise.


What is the best good available transistor or other parts? All parts he 
tested where just to good.


Thank you!

- Henry

--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Calculate spectral content from a series of zero crossing time stamps?

[ehydra]

LeCroy has a paper with a short explanation that I found useful:

http://www.lecroy.com/files/WhitePapers/WP_TechBrief_Var_of_Time.pdf


This look to me very similar to this:
http://pstca.com/sampler/index.htm

- Henry

--
ehydra.dyndns.info

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Calculate spectral content from a series of zerocrossing time stamps?

[ehydra]

SpectrumLab uses the Goertzel-Algorithm to trim the time reference to 
the millisecond range. Maybe that is comparable and as algoritm 
transverable?


- Henry


J. L. Trantham schrieb:

DFT?  Direct Fourier Transform?

Thanks,

Joe

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Tijd Dingen
Sent: Monday, February 07, 2011 9:02 PM
To: time-nuts@febo.com
Subject: [time-nuts] Calculate spectral content from a series of
zerocrossing time stamps?




Consider the following scenario. We have a signal source of about 10 kHz,
with unknown phase noise. Let's for simplicity's sake assume for now that
the phase noise is large enough that it will be detectable by the following
approach.

We measure every zero crossing with lets say 1 ns accuracy. So we have a
signal with a nominal period of 100 us, and we can measure every zero
crossing to within 1 ns. This gives you ~ 10,000 data points every second.

Now how does one efficiently calculate the spectral content based on these
10, zero crossings? The end result would be the spectral density,
centered around that nominal 10 kHz frequency.


From what I could find so far, one method to go about this is use a

Lomb/Scargle Periodogram. And specifically the method by Press & Rybicki
that extirpolates the unevenly timed samples to an regular timed mesh, after
which a regular DFT is done.

This is a nice enough approach, but you pay a computational price for the
fact that this algorithm is able to handle more generic inputs than is
needed in this particular case. So possibly there is a more efficient
method, only which one?


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] 10MHz to 80MHz frequency multiplier suggestions

[ehydra]

I suggest to ask LTC first for what is required. Personally I think one 
of the clock multipliers for SONET etc should be enough. silabs have 
several parts, others too.


If I remember correctly, I've seen a App Note describing oscillator 
requirements at LTC website.


- Henry


Elio Corbolante schrieb:

Rick Karlquist wrote:

You will be much happier with three doublers in cascade.
Try copying the HP8662 doublers as an example. We also
did this in the HP5071 (no I don't have schematics handy
at this time).


I searched for the 8662/3 schematics, but I only found low resolution PDFs.
Even for the 5071A I found a service manual (assembly) but it does not
contain detailed schematics:
Is there a kind soul among you, who have one of the required schematics?

_   Elio.

P.S. BTW, I exactly do not know the characteristics (phase noise) of the
original XTAL oscillator installed on Perseus, so I can't give more details
on my real requirements


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Distributed DDS

[ehydra]

I'm not sure if I overview the problem correctly. Hm, why not run the 
cable back and measure the round time? Half this time und you know the 
delay of one way. Then you can shift this with a PLL away.


A similar scheme is used in almost all modern PC clock distribution 
chips. A bunch of PLLs on the chip. Severals are available. For example 
Cypress Semi.


- Henry


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] spur prediction DDS software

[ehydra]

I don't know how good it has to be but have you considered the Si570 or 
even one of the bigger more power hungry candidates from silabs?


Really easy to drive this chip!

- Henry

Luis Cupido schrieb:

Jim, Bob, Henry, Brian,
Thanks to all.
Very good.

yeap, I do work on matlab so I think there is plenty now
to keep me busy ;-)

tks.

Luis Cupido
ct1dmk.


p.s.(what's cooking)
I need a relatively narrow tunning range
but absolutely free of close in spurs,
willing to see if a modest size DDS
(inside an FPGA) will do so... and what parameters will
be...


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] power spectrum of hard limiter output

[ehydra]

Hi Magnus -

Well. I made homework for sure. Endless viewed websites what others had 
done.
We all seek for the singularity of beauty in our art. At the moment this 
is a CD4007 or similar without AGC. Cheap, effective. Not oversized. I 
came from TCA440. One of the not many receiver chips where the IF is at 
one output reachable. Then I found I must increase carrier frequency 
beyound 30MHz. So the integrated mixer entered useless. I used an 
external device. Next I found that the integrated IF-strip is not one of 
the quiets... Remembering several statements about using CMOS inverters 
in s.e.d. for analog reasons, the way was clear...


Implementing an AGC makes the design much more complicated. Can 
oscillate etc.


Going without AGC seems a reasonable way if the modulation is one of the 
phase modulation systems where amplitude is not very important.


Then look how big is the dynamic range of a simple CMOS inverter.

Meanwhile I found two examples made by others. So the way looks not to 
idiotic ;-)


- Henry


Magnus Danielson schrieb:

I find it more and more curious a working concept not to find in the
I-net. I'm looking several weeks. Maybe wrong keywords.


Well, have you considered what an AGC might do for you?
It has been the traditional way of reducing the effect of signal level 
on phase-detector gain and hence on the loop gain. The hard-limiter text 
is to be seen in this context where the SNR steers the compression 
factor, i.e. change of loop gain.


Cheers,
Magnus


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] power spectrum of hard limiter output

[ehydra]

Magnus Danielson schrieb:

On 27/01/11 20:19, ehydra wrote:

I found chapter Appendix 7A "Analysis of interference in a hard limiter"
There is a half page with a couple of formulas. Not much, not
practically oriented. Only idealized hard-limiters.

I'm interested in SOFT-limiters!


Jim's problem was with a hard-limiter so what I tossed his way was 
relevant to him.


I must say 'soft-limiter' is new to me, too! Sorry for pirate a thread.




For soft-limiters, papers like this may be of assistance:
http://webs.wichita.edu/depttools/depttoolsmemberfiles/ECE/Kwon%20Wireless/95Aug.pdf 



Interesting. 4dB below limit.





Hm. Does the writer seen a real working system once upon in time?


Yes. What defines a working system is however covering a lot of systems 
and particulars of some systems can cover many books on its own without 
making other things irrelevant.


He he. We have many nonsense amateur info on the Web. Then many 
theoretical papers. A small gap between is useful for the practical 
oriented people. Unfortunately, this gap is just to slim.



I find it more and more curious a working concept not to find in the 
I-net. I'm looking several weeks. Maybe wrong keywords.



Thanks!
- Henry

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Mass vs BTU Function

[ehydra]

Thermal energy in metals are measured in 'pro kg'. The rest is just 
calculation.


From a practical standpoint I would use copper. You can solder and weld 
it more easely.

Look for how head-fin spreaders work for CPUs.

- Henry


Perry Sandeen schrieb:

List,

Please help me with this physics question.

If one has a given cube, say 2 x 2 x 2 inches.  And one has the choice of 
aluminum, copper, or lead (just for an example).  Will each store or hold the 
same amount of BTUs or does the density make a difference?

IF the density makes a difference, can someone give me the approximate 
difference?

The practical end of this question is consideration of thermal mass surrounding 
an oscillator,

TIA 


Perrier


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] spur prediction DDS software

[ehydra]

The best once I found is this:
http://www.holmea.demon.co.uk/FracN/Simulate.htm

- Henry


Luis Cupido schrieb:

Hi,

Is there a DDS spur prediction software around ?

I mean for an arbitrary DDS design, like I would
implement with logic or fpga etc.

A code where I can enter nr of bits adc bits etc.

(not a thing for a particular analog-devices chip or
other dds chip)



___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] power spectrum of hard limiter output

[ehydra]

I found chapter Appendix 7A "Analysis of interference in a hard limiter"
There is a half page with a couple of formulas. Not much, not 
practically oriented. Only idealized hard-limiters.


I'm interested in SOFT-limiters!

Hm. Does the writer seen a real working system once upon in time?

- Henry


Magnus Danielson schrieb:

Hi,

On 27/01/11 01:30, ehydra wrote:

Hm Magnus -

I heard of it as a standard text book but never looked inside. And not
known that it describes limiter behaviour.

Anyway. Now I have a version of 2004, 3rd edition, and cannot find the
mentioned chapter. Please post a little more info, so I can find with
keywords.


Mine is second edition.

It is part of Chapter six - Loop components and there is in mine a 
sub-chapter 6.4 Limiters which gives these descriptions prior to discuss 
noise effects on phase-detectors.


Cheers,
Magnus


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] power spectrum of hard limiter output

[ehydra]

Hm Magnus -

I heard of it as a standard text book but never looked inside. And not 
known that it describes limiter behaviour.


Anyway. Now I have a version of 2004, 3rd edition, and cannot find the 
mentioned chapter. Please post a little more info, so I can find with 
keywords.


Thank you!
- Henry


Magnus Danielson schrieb:

On 26/01/11 00:35, ehydra wrote:

Hi Magnus -

What book? This one maybe:
Gardner F M PHASELOCK TECHNIQUES Wiley & Sons 1966


Yes, but there is later revisions of it. A classic on PLLs.

Cheers,
Magnus


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.