Re: [time-nuts] Tight PLL Tester

[Tom Van Baak]

If there are any Nuts out there interested in helping to make available to 
other Freq-Nuts a SIMPLE tester that I have found to be a VERY useful low 
cost tool,


Warren,

Yes, I think it's a good idea for a couple of people to try to
duplicate your results; either to validate the resolution and
features that you're claiming, or to locate or quantify the
limitations in your implementation. Either way it will be a
learning experience for you, and for the group.

To that end, would you be able this week to write a quick
word document or readme or web page with photo(s) of
your setup, schematic, parts list, specific make/model of
the equipment that you're using, etc. Since you say it is
a simple setup, I suspect a number of us would then be
able to dig in our parts bin and mimic your prototype
as close as possible and then objectively measure how
it works compared to other phase noise measurement
systems.

/tvb




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Re: [time-nuts] TBolt self survey

[bg]

Charles, Raj,

> Raj wrote:
>
>>My GPS reading is about 850 +- 1
>>The "official" height ASL = 920
>>This calculator gives me ~936
>>So what should I use ?
>
> Use the self-survey result.  The GPS isn't wrong, it's just reporting
> your altitude in a different system than you are used to.  The
> calculator allows you to check the GPS-reported altitude in the
> system that you are familiar with.
>
> Specifically, the calculator translates the GPS altitude (which is
> specified not with respect to actual mean sea level, but rather to an
> abstract, calculated "geoid") to one more familiar to you (specified
> with respect to mean sea level).  In your case, 936 is in pretty good
> agreement with 920, telling you that the GPS-reported value is plausible.
>
> Best regards,
>
> Charles

The wording is somewhat dangerous. GPGGA - the most common GPS message ! -
gives altitude reltive to Mean Sea Level. MSL height/altitude is the same
as Geoid height/altitude. [1]

The most basic GPS altitude is indeed height above the (WGS84) ellipsoid
(HAE). This is the "best" ellipsoid approximation of the geoid on a global
scale, as chosen in the WGS84 datum.

The difference between MSL (real world) and HAE is called geoid separation
or height of the geoid. This difference will be in the range of ca +-100m.
It can be calculated for each (horizontal) position on earth with the help
of a geoid model (ie EGM96 [2]). A full model to reach cm or dm level
accuracy for the whole earth requires a large model. A coarse lockup table
or a local model is easier to implement inside a small GPS receiver. The
GGA message will also give you the receiver used geoid separation. [1]

[1] http://www.gpsinformation.org/dale/nmea.htm#GGA
[2]  http://cddis.nasa.gov/926/egm96/egm96.html

--

Björn


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[time-nuts] Symmetricom Announces Commercial Time-Scale System

[Christopher Hoover]

fyi.  -ch.


 Symmetricom Announces Commercial Time-Scale System

February 10, 2010


http://www.gpsworld.com/wireless/timing/news/symmetricom-announces-commercial-time-scale-system-9518

Symmetricom, Inc., a supplier of precise time and frequency 
technologies, has announced the Time-Scale System 
, 
a fully integrated redundant nanosecond-level timing solution. Designed 
for international metrology, aerospace, and defense customers, the 
system combines multiple high-performance atomic clocks in a time scale 
that drives a local real-time clock (RTC).


Comparable to the world's best national laboratories that compute a 
local time scale steered to agree with Universal Coordinated Time (UTC), 
Symmetricom said, the Time-Scale System is designed for national timing 
laboratories in countries that need to establish traceable time. It is 
also designed for government or civilian agencies that require precision 
timing capabilities independent of a GNSS.


[ . . . ]



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[time-nuts] Duplicate messages

[Bruce Griffiths]

John

As far as I can tell only one copy of one of my recent messages was 
added to the time nuts archives.

However 2 copies appear to have been sent to those on the list.
My machine indicates that only one copy was posted to the list.

Bruce



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Re: [time-nuts] Advice on 10 MHz isolation/distribution amplifier

[Bruce Griffiths]

Attn: John Ackermann

Not sure what happened to produce 2 identical posts but as far as I can 
tell I only posted this once.


Bruce

Bruce Griffiths wrote:

Clay

Circuit schematic for a more recent JPL isolation amplifier design is 
attached.


Bruce





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Re: [time-nuts] Advice on 10 MHz isolation/distribution amplifier

[Bruce Griffiths]

Clay

Circuit schematic for one of the JPL isolation amplifiers is attached.
Unfortunately (apart from the few I and others may have) these 
transistors are difficult to obtain.

However modern equivalents could be substituted.

Bruce

life speed wrote:

Avoiding transformers and inductors will make it virtually impossible to
achieve very low phase noise as the dc gain from say the base of any
transistor in the chain to the output will degrade the flicker phase
noise. Using transformers or using an inductor to shunt any collector
resistors reduces the flicker phase modulation to low levels.

JPL in the past has built capacitively coupled complementary symmetry
isolation amplifiers that avoid transformers but suffer from dc loop
gains of around 3 or so.

Using complementary symmetry can be a good way of keeping the dc current
down.

How much reverse isolation do you need?
How low does the phase noise floor need to be?
What about flicker phase noise, how low does that need to be?

Bruce

Right, what do I really need? I only have a really good 10 MHz OCXO crystal 
oscillator to distribute, so about -120 dBc at 10 Hz, -140 dBc/Hz at 100 Hz, - 
150 dBc/Hz at 1KHz, and -155 dBc/Hz noise floor.  No maser or cesium clock, 
living in the world of practical realities here.  Of course I would like to be 
3 - 6 dB better than the OCXO numbers.

Reverse isolation is my primary interest in the distribution amplifier 
approach, although the OCXO is good enough that a sloppy approach could 
contaminate the phase noise also.  I would like to accomplish at least 100 dB 
reverse isolation at frequencies below 20 MHz, but more is better in this case. 
 The 10 MHz is running all over a noisy aircraft, to potentially noisy 
receivers.

In reading up on the subject, I have come to understand that DC gain is the 
bane of close-in phase noise.  Given that flicker noise is such a headache for 
we frequency synthesizer designers, I guess this should come as no surprise.

Clay (AKA Lifespeed)




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Re: [time-nuts] Advice on 10 MHz isolation/distribution amplifier

[Bruce Griffiths]

Clay

You could try something like the attached circuit schematic.
Austron used buffer amplifiers like this albeit without the 
complementary symmetry output stage.

There are no transformers and the dc gain is low.
Simulated reverse isolation at 10MHz is around 120dB.
Simulated crosstalk between the 2 outputs is around -100dB at 10MHz.
The transistor models used usually predict reverse isolation reasonably 
accurately at 10MHz.

The phase noise floor should be around -170dBc/Hz or less at 100kHz offset.

V1 is the input signal.

The 50 ohm sources  V6, V7 shown at the outputs are used for simulation 
purposes (reverse isolation and crosstalk).


Off course, more elaborate power supply decoupling will be necessary to 
avoid degrading reverse isolation and crosstalk.


If you are really desperate to reduce the dc current the output 
transistors could be operated in class B.

However the distortion will increase a little.

Bruce

life speed wrote:

Avoiding transformers and inductors will make it virtually impossible to
achieve very low phase noise as the dc gain from say the base of any
transistor in the chain to the output will degrade the flicker phase
noise. Using transformers or using an inductor to shunt any collector
resistors reduces the flicker phase modulation to low levels.

JPL in the past has built capacitively coupled complementary symmetry
isolation amplifiers that avoid transformers but suffer from dc loop
gains of around 3 or so.

Using complementary symmetry can be a good way of keeping the dc current
down.

How much reverse isolation do you need?
How low does the phase noise floor need to be?
What about flicker phase noise, how low does that need to be?

Bruce

Right, what do I really need? I only have a really good 10 MHz OCXO crystal 
oscillator to distribute, so about -120 dBc at 10 Hz, -140 dBc/Hz at 100 Hz, - 
150 dBc/Hz at 1KHz, and -155 dBc/Hz noise floor.  No maser or cesium clock, 
living in the world of practical realities here.  Of course I would like to be 
3 - 6 dB better than the OCXO numbers.

Reverse isolation is my primary interest in the distribution amplifier 
approach, although the OCXO is good enough that a sloppy approach could 
contaminate the phase noise also.  I would like to accomplish at least 100 dB 
reverse isolation at frequencies below 20 MHz, but more is better in this case. 
 The 10 MHz is running all over a noisy aircraft, to potentially noisy 
receivers.

In reading up on the subject, I have come to understand that DC gain is the 
bane of close-in phase noise.  Given that flicker noise is such a headache for 
we frequency synthesizer designers, I guess this should come as no surprise.

Clay (AKA Lifespeed)




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Re: [time-nuts] Advice on 10 MHz isolation/distribution amplifier

[Bob Camp]

Hi

Is your OCXO vibration isolated?

If not and it's got "typical" g sensitivity, your phase noise in an aircraft 
may be much worse than the static numbers.


If you are sending the signal a distance to your systems, a balanced feed 
may be the only way you will deliver a clean signal at the far end.


Bob

--
From: "life speed" 
Sent: Wednesday, February 10, 2010 10:03 PM
To: 
Subject: Re: [time-nuts] Advice on 10 MHz isolation/distribution amplifier


Avoiding transformers and inductors will make it virtually impossible to
achieve very low phase noise as the dc gain from say the base of any
transistor in the chain to the output will degrade the flicker phase
noise. Using transformers or using an inductor to shunt any collector
resistors reduces the flicker phase modulation to low levels.

JPL in the past has built capacitively coupled complementary symmetry
isolation amplifiers that avoid transformers but suffer from dc loop
gains of around 3 or so.

Using complementary symmetry can be a good way of keeping the dc current
down.

How much reverse isolation do you need?
How low does the phase noise floor need to be?
What about flicker phase noise, how low does that need to be?

Bruce

Right, what do I really need? I only have a really good 10 MHz OCXO 
crystal oscillator to distribute, so about -120 dBc at 10 Hz, -140 dBc/Hz 
at 100 Hz, - 150 dBc/Hz at 1KHz, and -155 dBc/Hz noise floor.  No maser or 
cesium clock, living in the world of practical realities here.  Of course 
I would like to be 3 - 6 dB better than the OCXO numbers.


Reverse isolation is my primary interest in the distribution amplifier 
approach, although the OCXO is good enough that a sloppy approach could 
contaminate the phase noise also.  I would like to accomplish at least 100 
dB reverse isolation at frequencies below 20 MHz, but more is better in 
this case.  The 10 MHz is running all over a noisy aircraft, to 
potentially noisy receivers.


In reading up on the subject, I have come to understand that DC gain is 
the bane of close-in phase noise.  Given that flicker noise is such a 
headache for we frequency synthesizer designers, I guess this should come 
as no surprise.


Clay (AKA Lifespeed)




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Re: [time-nuts] Advice on 10 MHz isolation/distribution amplifier

[life speed]

Avoiding transformers and inductors will make it virtually impossible to 
achieve very low phase noise as the dc gain from say the base of any 
transistor in the chain to the output will degrade the flicker phase 
noise. Using transformers or using an inductor to shunt any collector 
resistors reduces the flicker phase modulation to low levels.

JPL in the past has built capacitively coupled complementary symmetry 
isolation amplifiers that avoid transformers but suffer from dc loop 
gains of around 3 or so.

Using complementary symmetry can be a good way of keeping the dc current 
down.

How much reverse isolation do you need?
How low does the phase noise floor need to be?
What about flicker phase noise, how low does that need to be?

Bruce

Right, what do I really need? I only have a really good 10 MHz OCXO crystal 
oscillator to distribute, so about -120 dBc at 10 Hz, -140 dBc/Hz at 100 Hz, - 
150 dBc/Hz at 1KHz, and -155 dBc/Hz noise floor.  No maser or cesium clock, 
living in the world of practical realities here.  Of course I would like to be 
3 - 6 dB better than the OCXO numbers.

Reverse isolation is my primary interest in the distribution amplifier 
approach, although the OCXO is good enough that a sloppy approach could 
contaminate the phase noise also.  I would like to accomplish at least 100 dB 
reverse isolation at frequencies below 20 MHz, but more is better in this 
case.  The 10 MHz is running all over a noisy aircraft, to potentially noisy 
receivers.

In reading up on the subject, I have come to understand that DC gain is the 
bane of close-in phase noise.  Given that flicker noise is such a headache for 
we frequency synthesizer designers, I guess this should come as no surprise.

Clay (AKA Lifespeed)


  

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Re: [time-nuts] Advice on 10 MHz isolation/distribution amplifier

[Bob Camp]

Hi

How quiet does in need to be (phase noise)?

How clean does it need to be (harmonics)?

How much isolation / how much gain do you need?

How well do the outputs need to be matched / do you need a broad band match?

Does the issue with transformers also extend to other inductors?

Is cost / military components / small size / radiation tolerance an issue?

The answer to your question could be any of several bipolar transistor 
circuits, op amps, right up to "can't be done" based on some of the answers.


Bob

--
From: "life speed" 
Sent: Wednesday, February 10, 2010 8:27 PM
To: 
Subject: [time-nuts] Advice on 10 MHz isolation/distribution amplifier


Hello everyone,

I am new to this list, happened across it while searching on distribution 
amplifiers.


I need to design a 10 MHz isolation/distribution amplifier with two 
outputs for a high-vibration wide temperature range environment.  I was 
considering using a design based on the NIST article 'A new 5 and 10 MHz 
distribution amp', most likely the third incarnation, as I cannot tolerate 
modulation of the signal via the transformer.


I have looked at the work by Gerhard Hoffman, which is impressive. 
However, the transformer remains.  I should mention I am also limited to 
15V power supply, and need to output into 50 ohms at 10 dBm.  Ideally DC 
current will be minimized, preferably 20 - 30 mA per channel.  I can 
generate a negative power supply if necessary, but would prefer not to.


If anybody can offer tips so I don't undertake to reinvent the wheel, it 
would be appreciated.


Thanks in advance,
 - Lifespeed




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Re: [time-nuts] TBolt self survey

[Raj]

Ignatio and Charles,

Thanks. Makes sense to me now. I am interested only in the 10MHz frequency 
generated and I suppose that it may not be affected by slight mismatch.

Raj


>Raj,
>Use the GPS reading, at least it has to be consistent with itself...
>
>Ignacio


At 11-02-10, you wrote:
>Raj wrote:
>
>>My GPS reading is about 850 +- 1
>>The "official" height ASL = 920
>>This calculator gives me ~936
>>So what should I use ?
>
>Use the self-survey result.  The GPS isn't wrong, it's just reporting your 
>altitude in a different system than you are used to.  The calculator allows 
>you to check the GPS-reported altitude in the system that you are familiar 
>with.
>
>Specifically, the calculator translates the GPS altitude (which is specified 
>not with respect to actual mean sea level, but rather to an abstract, 
>calculated "geoid") to one more familiar to you (specified with respect to 
>mean sea level).  In your case, 936 is in pretty good agreement with 920, 
>telling you that the GPS-reported value is plausible.
>
>Best regards,
>
>Charles
>
>
>
>
>
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>and follow the instructions there.

-- 
Raj, VU2ZAP
Bangalore, India. 


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[time-nuts] New Thunderbolt AMU to dBc conversion data

[Mark Sims]

Here is a new and improved AMU to dBc conversion file.  It smoothes out a bump 
in the data around 3-6 AMU.  This file is also formatted comma delimited for 
easier import into spreadsheets.  You may need to delete the first (header) 
line.


  
_
Hotmail: Trusted email with powerful SPAM protection.
http://clk.atdmt.com/GBL/go/201469227/direct/01/; AMU   dBc
  0.0,  20.0 
  0.1,  20.4 
  0.2,  20.8 
  0.3,  21.2 
  0.4,  21.6 
  0.5,  22.0 
  0.6,  22.4 
  0.7,  22.8 
  0.8,  23.2 
  0.9,  23.6 
  1.0,  24.0 
  1.1,  24.4 
  1.2,  24.8 
  1.3,  25.2 
  1.4,  25.6 
  1.5,  26.0 
  1.6,  26.4 
  1.7,  26.8 
  1.8,  27.2 
  1.9,  27.6 
  2.0,  28.0 
  2.1,  28.4 
  2.2,  28.8 
  2.3,  29.2 
  2.4,  29.6 
  2.5,  30.0 
  2.6,  30.3 
  2.7,  30.6 
  2.8,  30.9 
  2.9,  31.2 
  3.0,  31.6 
  3.1,  31.9 
  3.2,  32.2 
  3.3,  32.5 
  3.4,  32.8 
  3.5,  33.1 
  3.6,  33.4 
  3.7,  33.7 
  3.8,  34.0 
  3.9,  34.3 
  4.0,  34.6 
  4.1,  34.8 
  4.2,  35.0 
  4.3,  35.2 
  4.4,  35.4 
  4.5,  35.6 
  4.6,  35.8 
  4.7,  36.0 
  4.8,  36.2 
  4.9,  36.4 
  5.0,  36.6 
  5.1,  36.8 
  5.2,  37.0 
  5.3,  37.2 
  5.4,  37.4 
  5.5,  37.6 
  5.6,  37.8 
  5.7,  38.0 
  5.8,  38.2 
  5.9,  38.4 
  6.0,  38.6 
  6.1,  38.8 
  6.2,  39.0 
  6.3,  39.2 
  6.4,  39.4 
  6.5,  39.6 
  6.6,  39.8 
  6.7,  39.9 
  6.8,  40.0 
  6.9,  40.1 
  7.0,  40.2 
  7.1,  40.3 
  7.2,  40.4 
  7.3,  40.5 
  7.4,  40.6 
  7.5,  40.7 
  7.6,  40.8 
  7.7,  40.9 
  7.8,  41.0 
  7.9,  41.1 
  8.0,  41.2 
  8.1,  41.3 
  8.2,  41.4 
  8.3,  41.5 
  8.4,  41.6 
  8.5,  41.7 
  8.6,  41.8 
  8.7,  41.9 
  8.8,  42.0 
  8.9,  42.1 
  9.0,  42.2 
  9.1,  42.3 
  9.2,  42.4 
  9.3,  42.5 
  9.4,  42.6 
  9.5,  42.7 
  9.6,  42.8 
  9.7,  42.9 
  9.8,  43.0 
  9.9,  43.1 
 10.0,  43.2 
 10.1,  43.3 
 10.2,  43.4 
 10.3,  43.5 
 10.4,  43.6 
 10.5,  43.7 
 10.6,  43.7 
 10.7,  43.8 
 10.8,  43.9 
 10.9,  44.0 
 11.0,  44.1 
 11.1,  44.2 
 11.2,  44.3 
 11.3,  44.4 
 11.4,  44.5 
 11.5,  44.6 
 11.6,  44.7 
 11.7,  44.8 
 11.8,  44.9 
 11.9,  45.0 
 12.0,  45.1 
 12.1,  45.2 
 12.2,  45.3 
 12.3,  45.4 
 12.4,  45.4 
 12.5,  45.5 
 12.6,  45.5 
 12.7,  45.6 
 12.8,  45.6 
 12.9,  45.7 
 13.0,  45.7 
 13.1,  45.8 
 13.2,  45.8 
 13.3,  45.9 
 13.4,  46.0 
 13.5,  46.0 
 13.6,  46.1 
 13.7,  46.1 
 13.8,  46.2 
 13.9,  46.2 
 14.0,  46.3 
 14.1,  46.3 
 14.2,  46.4 
 14.3,  46.5 
 14.4,  46.6 
 14.5,  46.7 
 14.6,  46.8 
 14.7,  46.8 
 14.8,  46.9 
 14.9,  46.9 
 15.0,  47.0 
 15.1,  47.0 
 15.2,  47.1 
 15.3,  47.1 
 15.4,  47.2 
 15.5,  47.2 
 15.6,  47.3 
 15.7,  47.3 
 15.8,  47.4 
 15.9,  47.4 
 16.0,  47.5 
 16.1,  47.5 
 16.2,  47.6 
 16.3,  47.6 
 16.4,  47.7 
 16.5,  47.7 
 16.6,  47.8 
 16.7,  47.8 
 16.8,  47.9 
 16.9,  47.9 
 17.0,  48.0 
 17.1,  48.0 
 17.2,  48.1 
 17.3,  48.1 
 17.4,  48.2 
 17.5,  48.2 
 17.6,  48.3 
 17.7,  48.3 
 17.8,  48.4 
 17.9,  48.4 
 18.0,  48.5 
 18.1,  48.5 
 18.2,  48.6 
 18.3,  48.6 
 18.4,  48.7 
 18.5,  48.7 
 18.6,  48.8 
 18.7,  48.8 
 18.8,  48.9 
 18.9,  48.9 
 19.0,  49.0 
 19.1,  49.0 
 19.2,  49.0 
 19.3,  49.0 
 19.4,  49.1 
 19.5,  49.1 
 19.6,  49.1 
 19.7,  49.2 
 19.8,  49.2 
 19.9,  49.2 
 20.0,  49.3 
 20.1,  49.3 
 20.2,  49.3 
 20.3,  49.4 
 20.4,  49.4 
 20.5,  49.4 
 20.6,  49.5 
 20.7,  49.5 
 20.8,  49.5 
 20.9,  49.6 
 21.0,  49.6 
 21.1,  49.6 
 21.2,  49.7 
 21.3,  49.7 
 21.4,  49.7 
 21.5,  49.8 
 21.6,  49.8 
 21.7,  49.8 
 21.8,  49.9 
 21.9,  49.9 
 22.0,  49.9 
 22.1,  50.0 
 22.2,  50.0 
 22.3,  50.0 
 22.4,  50.1 
 22.5,  50.1 
 22.6,  50.1 
 22.7,  50.2 
 22.8,  50.2 
 22.9,  50.2 
 23.0,  50.3 
 23.1,  50.3 
 23.2,  50.3 
 23.3,  50.4 
 23.4,  50.4 
 23.5,  50.4 
 23.6,  50.5 
 23.7,  50.5 
 23.8,  50.5 
 23.9,  50.6 
 24.0,  50.6 
 24.1,  50.6 
 24.2,  50.7 
 24.3,  50.7 
 24.4,  50.7 
 24.5,  50.8 
 24.6,  50.8 
 24.7,  50.8 
 24.8,  50.9 
 24.9,  50.9 
 25.0,  50.9 
 25.1,  51.0 
 25.2,  51.0 
 25.3,  51.0 
 25.4,  51.1 
 25.5,  51.1
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Re: [time-nuts] Advice on 10 MHz isolation/distribution amplifier

[Bruce Griffiths]

life speed wrote:

Hello everyone,

I am new to this list, happened across it while searching on distribution 
amplifiers.

I need to design a 10 MHz isolation/distribution amplifier with two outputs for 
a high-vibration wide temperature range environment.  I was considering using a 
design based on the NIST article 'A new 5 and 10 MHz distribution amp', most 
likely the third incarnation, as I cannot tolerate modulation of the signal via 
the transformer.

I have looked at the work by Gerhard Hoffman, which is impressive.  However, 
the transformer remains.  I should mention I am also limited to 15V power 
supply, and need to output into 50 ohms at 10 dBm.  Ideally DC current will be 
minimized, preferably 20 - 30 mA per channel.  I can generate a negative power 
supply if necessary, but would prefer not to.

If anybody can offer tips so I don't undertake to reinvent the wheel, it would 
be appreciated.

Thanks in advance,
  - Lifespeed
   
Avoiding transformers and inductors will make it virtually impossible to 
achieve very low phase noise as the dc gain from say the base of any 
transistor in the chain to the output will degrade the flicker phase 
noise. Using transformers or using an inductor to shunt any collector 
resistors reduces the flicker phase modulation to low levels.


JPL in the past has built capacitively coupled complementary symmetry 
isolation amplifiers that avoid transformers but suffer from dc loop 
gains of around 3 or so.


Using complementary symmetry can be a good way of keeping the dc current 
down.


How much reverse isolation do you need?
How low does the phase noise floor need to be?
What about flicker phase noise, how low does that need to be?

Bruce


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Re: [time-nuts] TBolt self survey

[Charles P. Steinmetz]

Raj wrote:


My GPS reading is about 850 +- 1
The "official" height ASL = 920
This calculator gives me ~936
So what should I use ?


Use the self-survey result.  The GPS isn't wrong, it's just reporting 
your altitude in a different system than you are used to.  The 
calculator allows you to check the GPS-reported altitude in the 
system that you are familiar with.


Specifically, the calculator translates the GPS altitude (which is 
specified not with respect to actual mean sea level, but rather to an 
abstract, calculated "geoid") to one more familiar to you (specified 
with respect to mean sea level).  In your case, 936 is in pretty good 
agreement with 920, telling you that the GPS-reported value is plausible.


Best regards,

Charles





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[time-nuts] Advice on 10 MHz isolation/distribution amplifier

[life speed]

Hello everyone,

I am new to this list, happened across it while searching on distribution 
amplifiers.

I need to design a 10 MHz isolation/distribution amplifier with two outputs for 
a high-vibration wide temperature range environment.  I was considering using a 
design based on the NIST article 'A new 5 and 10 MHz distribution amp', most 
likely the third incarnation, as I cannot tolerate modulation of the signal via 
the transformer.

I have looked at the work by Gerhard Hoffman, which is impressive.  However, 
the transformer remains.  I should mention I am also limited to 15V power 
supply, and need to output into 50 ohms at 10 dBm.  Ideally DC current will be 
minimized, preferably 20 - 30 mA per channel.  I can generate a negative power 
supply if necessary, but would prefer not to.

If anybody can offer tips so I don't undertake to reinvent the wheel, it would 
be appreciated.

Thanks in advance,
 - Lifespeed 


  

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Re: [time-nuts] TBolt self survey

[EB4APL]

Raj,
Use the GPS reading, at least it has to be consistent with itself...

Ignacio


Raj wrote:

My GPS reading is about 850 +- 1
The "official" height ASL = 920

This calculator gives me ~936

So what should I use ?

Thanks
Raj
  



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Re: [time-nuts] TBolt self survey

[Raj]

My GPS reading is about 850 +- 1
The "official" height ASL = 920

This calculator gives me ~936

So what should I use ?

Thanks
Raj

At 10-02-10, you wrote:
>Try to find your correct height here:
>http://sps.unavco.org/geoid/
>
>If you put in your correct coordinates without any input for the elevation, 
>you will get theorthometric height, which is the GPS ellipsoidal height 
>minus geoid height. That is the amount you need to subtract from 
>your Thunderbolt GPS height in order to get your local geodetic height 
>(WGS84). 
>
>Filling in the Thunderbolt GPS height you will get the 'real' height 
>for your antenna...
>
>Some explanations:
>http://www.unavco.org/edu_outreach/tutorial/geoidcorr.html
>
>On my location I have always to reduce the GPS height by 46.623 m.
>Good luck with TB and the Lady Heather,
>
>Arnold, DK2WT
>
>
>
>On Wed, 10 Feb 2010 14:20:36 +0100, EB4APL wrote:
>
>>Raj,
>
>>Ask them about ellipsoidal and orthometric heights, or the local 
>>difference between the geoid and the WGS84 ellipsoid.  Also your long 
>>and lat may change depending of the Geodetic Reference System chosen.  
>>By default GPS receivers use WGS84 and ellipsoidal height.
>
>>73 de Ignacio, EB4APL
>
>>--
>>Raj wrote:
>>> Thanks Stan,
>>>
>>> That worked, I did not see the  control menu properly!
>>>
>>> I set the co-ords to 0 0 0 and started survey. The Tbolt found the Lat long 
>>> withing a few minutes and only the altitude is about 70 M below the 
>>> official figure for my place. I live a a few hundred meters from Bangalore 
>>> center and I am at the same height.. must check with the survey dept. down 
>>> the road!!
>>>
>>> 73
>>> Raj vu2zap
>>>
>>>
>>> At 10-02-10, you wrote:
>>>   
 Hello Raj,

 using the trimble T'boltMON software:

 Start with a "factory reset" in the control menu

 follow previous guidance of enabling the "save position" capability,

 Then to restart a survey

 go to the control menu (on left),
 select "restart self survey"


 In lady Heather V3.0 beta of 21 Jan '10 ( available from the KE5FX 
 website):
 keyboard enter a "s", for survey
 then "s" for a standard survey,
 use the default of 2000 samples,  for a start
 Then "enter"

 Time for me to go to bed.

 Please advise of progress.

 Stan,  W1LE


 Raj wrote:
 
> Thanks Stan,
>
> I did that but I can't where to "start the survey" in TBolt. In lady 
> heather there
> is a key for it.
>
> At 09-02-10, you wrote:
>  
>   
>> Hello Raj,
>>
>> that location is probably where the coordinates were last saved. or 
>> there abouts
>> Or those are the default factory settings from memory,
>> and new coordinates were never saved.
>>
>> redo the survey and save the results.
>>
>> using T'boltMON V2.60 on a PC:
>>
>> go to menu "set up",  then "self survey",   click on the "save position 
>> flag"
>> then "set survey",
>> then "save segment",
>> then "close"
>>
>> redo the survey and afterwards verify the local coordinates were saved.
>>
>> Lady Heather (software) can also be utilzed for these functions.
>>
>> Any problems, please advise.
>>
>> Stan, W1LE
>>
>>
>>
>> Raj wrote:
>>
>> 
>>>   Can someone point me to info that would clarify why my Tbolt's 
>>> self survey puts my house (AFAIK ~920M ASL, 13N 77.35E) in the Pacific 
>>> ocean, south of Vancouver and west of Seattle and about 10 meters under 
>>> water. I am doing something wrong for sure!
>>>
>>>   My sons iPhone gives me right co-ordinates but it's way off the 
>>> altitude.
>>>   
>>> Regards
>>>   
>
>
>
>
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-- 
Raj, VU2ZAP
Bangalore, India. 


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Re: [time-nuts] Injection locking

[Lux, Jim (337C)]

You might want to look for 
R. Adler, "A study of Locking Behavior in Oscillators"< Proc of IEEE, v 61, 
pp1380-1385, Oct 1973
Or
K. Kurokawa "Injection Locking of Microwave Solid State Oscillators", same 
issue, pp1386-1410.

Those seem to be papers that get cited a lot.
The coupled oscillator phased array schemes rely on the fact that the phase of 
the locked oscillator has a consistent relationship to how far the frequency is 
from the "rest" frequency.. if you push the rest frequency with a DC voltage 
(for instance), then you can get a DC voltage to phase control, which is quite 
convenient.  If you have a whole bunch of oscillators, you can just push the 
ones at the edge, and the ones in the middle couple to the ones next to them 
and the phase has a nice linear curve across the array.

I am reminded of our recent discussion on this list of an array of coupled 
mechanical oscillators.




> -Original Message-
> From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On 
> Behalf Of Kit Scally
> Sent: Wednesday, February 10, 2010 3:55 PM
> To: time-nuts@febo.com
> Cc: Kit Scally
> Subject: [time-nuts] Injection locking
> 
> Hi,
> 
> 
> As others have already noted, there's a paucity of circuits or down to
> earth advice on this topic - unless your poison is "millimetre wave"
> technology.

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Re: [time-nuts] Injection locking

[Lux, Jim (337C)]

> -Original Message-
> From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On 
> Behalf Of Kit Scally
> Sent: Wednesday, February 10, 2010 3:55 PM
> To: time-nuts@febo.com
> Cc: Kit Scally
> Subject: [time-nuts] Injection locking
> 
> Hi,
> 
> 
> As others have already noted, there's a paucity of circuits or down to
> earth advice on this topic - unless your poison is "millimetre wave"
> technology.
> I set out to GPS-lock my Icom 706 transceiver some while ago.  This uses
> a (single) hi-stability master 30MHz xtal oscillator.  With support from
> Murray (ZL1BPU), I decided to IL rather than generate an external
> GPS-locked 30MHz source.
> 
> The only reference other than that by Uzunoglu to IL oscillator design I
> managed to find was in Jessop, 4th Ed, 1994 (p9.50) which stated:
> 
> P1/P2 = [2Q*deltaF/F]^2
> 
> where:
> P1   = pwr of injected signal
> P2   = Oscillator (to be controlled) power
> Q= loaded Q of cavity (ie: xtal osc)
> F= oscillator frequency
> delta F = locking range
> 
> 

Since Q of the oscillator is basically F(center)/BW(cavity) your equation could 
reduce to 
2* F(center)/BW(cavity) * deltaF/F(center) = 2 * deltaF/BW(cavity)

Or, the power ratio is roughly the square of how far the signal is from the 3dB 
point of the oscillator.

That is, if the 3dB point of the closein sidebands extend 10 Hz, and your 
signal is 10Hz away, the injection power would have to equal the carrier power?

There's an interesting article out there where a whole raft of microwave oven 
magnetrons were harnessed together to make a microwave weed killer, and they 
comment that they all tend to lock together.

When it comes to coupled oscillator arrays, there's a whole lot of literature. 
Look for York and Pogorzelski as authors (Pogo is just down the hall from me at 
work.)  I don't know if he's done work with coupling at a subharmonic of the 
output frequency.  No reason why it wouldn't work.


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[time-nuts] Injection locking

[Kit Scally]

Hi,


As others have already noted, there's a paucity of circuits or down to
earth advice on this topic - unless your poison is "millimetre wave"
technology.
I set out to GPS-lock my Icom 706 transceiver some while ago.  This uses
a (single) hi-stability master 30MHz xtal oscillator.  With support from
Murray (ZL1BPU), I decided to IL rather than generate an external
GPS-locked 30MHz source.

The only reference other than that by Uzunoglu to IL oscillator design I
managed to find was in Jessop, 4th Ed, 1994 (p9.50) which stated:

P1/P2 = [2Q*deltaF/F]^2

where:
P1   = pwr of injected signal
P2   = Oscillator (to be controlled) power
Q= loaded Q of cavity (ie: xtal osc)
F= oscillator frequency
delta F = locking range

Working the formula backwards together with lab testing confirmed that
the greater the injection level, the greater the lock-in range and
vice-versa.
In practice, I coupled a +10dBm 10MHz square wave via a ~15dB attenuator
into the 30MHz xtal osc's "pulling inductor" via a 2 turn loop. This
allowed the IC-706 to lock-up within 10" of turning on from cold and
then remain in lock.

Theory suggests that lock sensitivity could be improved in this instance
if the 10MHz duty cycle was changed from 1:1 to 6 or 7:1, the idea being
that the narrower pulse should be <0.5 period of the frequency of the
oscillator to be locked.  I didn't pursue this avenue as the additional
stray GPSDO 10MHz signal present within the Icom didn't interfere too
greatly with WWV reception on 10MHz.  Spectran's display, however,
showed another story.

Measuring the lock BW with varying injection levels was an interesting
exercise !


On a related topic, I found some while ago - and promptly lost - a
graph/chart showing harmonic level variations with varying duty-cycle of
an input waveform.  This was to some degree a graphical representation
of the Wenzel document referenced by Bruce recently.  Has anyone got a
link to this document please ?


Kit
VK2LL 


---

> Joop,
>
> you may also search for "synchronous oscillator". You will find for
> example:
>
> http://www.amalgamate2000.com/radio-hobbies/radio/synchronous_oscillat
> or.htm
>
> Best regards
> Ulrich
>

>> Are there references to some practical circuits? That would be great.
>>snip
>> Cheers,
>> Joop
>>

--

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Re: [time-nuts] Low phase noise VCO

[Gerhard Hoffmann]

Bruce Griffiths wrote:

Not if one uses a balun.


or a 4 diode bridge rectifier :-)
(but more loss)

Gerhard

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Re: [time-nuts] CTS TCXO

[Stan, W1LE]

Hello The Net:

About a year ago I asked CTS Knights that very question.
They said it was a custom unit and they would NOT divulge the specs.
They referred me to SRS, their customer.

So I talked with SRS and they would only sell me a complete FS700 
rebuild service

for more money than I wanted to put into it.

I will talk to them again. Maybe now that the
LORAN C market has all but dried up,
they may have parts stock they want to clear out.

I am in need of this TCXO too.

Stan, W1LE



Lux, Jim (337C) wrote
Why not ask CTS? 
http://www.ctscorp.com/components/


http://www.ctscorp.com/feedback/techinfo.htm


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Re: [time-nuts] CTS TCXO

[Stan, W1LE]

Hello Geo,

Do you know where I can get a replacement 10 MHz VCXO to replace the one 
in my FS700 ?


I would prefer a drop in replacement like the CTS Knights.

Stan, W1LE Cape Cod




George Dubovsky wrote:

Marco,

My Stanford Research FS700 Loran receiver from about that time period has a
CTS Knights 970-2097-0 10 MHz ovenized oscillator in it, and it ran from +
and - 15 Vdc. I don't know if this is of any help at all.

73,

geo - n4ua

  



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Re: [time-nuts] Tight PLL Tester

[Bruce Griffiths]

It is essential to understand exactly how this system works in theory.
No amount of hand waving or protestations will make its problems go away 
if you use inappropriate signal processing methods.


The tight PLL (or any other PLL) forces the VCO (VCOXO int this case) to 
servo the fluctuations in the phase difference between the test 
oscillator and the VCO to zero within the PLL bandwidth.


To recover the phase fluctuations (assuming linearity of the VCO 
response to its voltage control input) the EFC voltage has to be integrated.
Leaving aside the problems of saturation with most (but not all) 
integrators, the phase fluctuations at the output of the VCO can be 
recovered (to within a scale factor) by sampling the integrator output 
to produce a set of synthesized phase samples. Alternatively one can 
calculate the first differences of the periodic sequence of phase 
samples to produce a series of scaled frequency averages.


In practice integrator saturation can be avoided by one of the following 
methods:


1) Using a precision voltage to frequency converter and a counter to 
form the integrator.

This is how NIST used to do it.
The VFC110 from TI appears suitable.
Avoid using a synchronous VFC (eg AD652) as they suffer from injection 
locking effects:

http://www.analog.com/static/imported-files/tutorials/MT-028.pdf
However if one samples the VFC integrator output at the end of each 
integration the effect of injection locking can be corrected for.

DVMs like the HP/Agilent 34401A use a variation of this technique.
Another thing to be aware of is that a DVM may have a built in RC low 
pass filter between its input terminals and its ADC.
The effect of this may be significant if the averaging time (integration 
period) is too short.


2) Use an integrating DVM to sample the EFC voltage.
The DVM samples are equivalent (to within a scale factor) to a set of 
frequency average samples.
However most (but not all) DVMs have a finite deadtime between 
successive integrations, where the internal integrator is rundown for 
example.
If one uses an integrating DVM with finite deadtime then the calculated 
values of ADEV should be corrected using the bias functions tabulated in 
NBS special publication 140 and elsewhere:

http://digicoll.manoa.hawaii.edu/techreports/PDF/NBS140.pdf

3) The PLL has a finite bandwidth so one can sample it at a sufficiently 
high rate (> 2X PLL bandwidth as the PLL isnt a brickwall filter) and 
calculate the required frequency averages from the sampled data. Unless 
a very high oversampling rate is used merely averaging the values of a 
fixed number of samples will be insufficiently accurate. Attempts to use 
an arbitrary low pass filter to average the samples will bias the 
results. The averaging filter must have a frequency response that is 
very close to the sinc response of an integrator with an integration 
period equal to the sample interval.
However this method is the most expensive as a high resolution ADC 
capable of relatively high sampling rates (10x the PLL bandwidth??) is 
required.


It is also essential to have sufficient isolation between the unit under 
test and the VCO to avoid significant mutual injection locking effects.
To a first approximation such injection locking affects the PLL 
parameters so that the PLL loop parameters need to be measured whilst 
the PLL is closed when isolation is insufficient.


If one uses one of the Minicircuits phase detectors rather than an 
arbitrary mixer then the isolation between the phase detector inputs is 
much higher (at low frequencies at least) than that for most mixers. 
Depending on the reverse isolation of the output buffers of the 
oscillators being compared this isolation may be sufficient to avoid an 
appreciable change in the PLL parameters. If the isolation is 
insufficient one then needs to use a suitable isolation amplifier 
between the the output of each oscillator and the phase detector.
The phase noise of the isolation amplifier should be lower than that of 
the reference VCO (VCOCXO in this case).
Suitable isolation amplifiers are readily available as are circuit 
schematics for isolation amplifiers known to have low phase noise you 
can build for youself.
Just building an isolation amplifier using fast opamps or cascaded MMICs 
without verifying the resultant phase noise is counterproductive.


Bruce

WarrenS wrote:


If there are any Nuts out there interested in helping to make 
available to other Freq-Nuts a SIMPLE tester that I have found to be a 
VERY useful low cost tool, contact me off line.

warrensjmail-...@yahoo.com

The tool is based on an OLD but seldom used method called the  "Tight 
Phase-Lock Loop Method of measuring Freq stability".
For a block diagram and short description see Figure 1.7 at 
http://tf.nist.gov/phase/Properties/one.htm#oneone


What I have made for my own use is a bread board of a simple analog 
version of  the NIST's block diagram.
There are of course many different ways to 

Re: [time-nuts] CTS TCXO

[gonzo .]

My experience is that CTS are very helpful in providing info on old products.

73,
 ian

> Date: Wed, 10 Feb 2010 22:09:05 +0100
> From: Marco IK1ODO 
> Subject: [time-nuts] CTS TCXO
> To: Discussion of precise time and frequency measurement
>   
> Message-ID: 
> Content-Type: text/plain; charset="us-ascii"; format=flowed
> 
> Hi all,
> 
> I have a CTS Knights TCXO, P/N 970-3832-0. Frequency is 10 MHz.
> Anyone knows the working voltage? Date code is from 1987, too old for 
> Internet :-)
> 
> 73 - Marco IK1ODO
***
  
_
If it exists, you'll find it on SEEK. Australia's #1 job site
http://clk.atdmt.com/NMN/go/157639755/direct/01/
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[time-nuts] Thunderbolt AMU to dBc conversion

[Mark Sims]

A while back there was a discussion on just how Trimble's AMU (amplitude 
measurement units) signal levels related to the dBc values.   Here is a 
conversion table.

It was generated by doing a 24 hour antenna signal level survey in dBc and 
another one in AMUs and then comparing the resulting values and doing some 
massaging and tweaking of the results.  The results might not be perfect,  but 
are probably as good as one is going to get...  
 
_
Hotmail: Trusted email with powerful SPAM protection.
http://clk.atdmt.com/GBL/go/201469227/direct/01/

amu2dbc
Description: Binary data
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Re: [time-nuts] Low phase noise VCO

[Don Latham]

cool. I found Xilinx CPLD's mounted up on through-hole boards for $18.00
at Digilent. I have other Digilent products and they're good...
Don

Nick Foster
>
> That's a great suggestion, Ulrich. Thanks. It took all of five minutes to
> implement in VHDL, and looks great.
>
> I also found Fox's "Xpresso" line of miniature synthesized VCXOs, and the
> numbers look pretty compelling. CMOS output, too. And, the best part,
> they're available off-the-shelf. Does anyone have experience with these in
> low-noise applications? They're ludicrously expensive (Digikey lists them
> for $47/ea in short qty), but if I can get some samples from Fox, it'll
> save me a lot of grief.
>
> I'll let you all know how it works out, and Don, if I get samples and they
> work OK I'll mail you some.
>
> Nick
>
>> From: df...@ulrich-bangert.de
>> To: time-nuts@febo.com
>> Date: Wed, 10 Feb 2010 09:02:30 +0100
>> Subject: Re: [time-nuts] Low phase noise VCO
>>
>> Nick,
>>
>> altough you have been asking for advice for the VCO I would like to draw
>> your attention on how you can improve your phase detector.
>> Edge-triggered
>> phase detectors are not bad, the even can work as frequency detectors if
>> you
>> are far from lock and help you to gain lock where a XOR would not.
>> However,
>> once you are CLOSE to a phase lock, a simple XOR makes the better phase
>> detector with less phase noise. There is a VERY easy circuit that
>> marriages
>> the best of both worlds. Google for the AD9901 frequence/phase detector
>> and
>> mimic their schematic of the first page into your CPLD. Have done this
>> with
>> different CPLDS from XILINX and ALTERA and has always worked very well
>> for
>> me in terms of frequency locking range and low phase noise.
>>
>> Best regards
>> Ulrich Bangert
>>
>> > -Ursprungliche Nachricht-
>> > Von: time-nuts-boun...@febo.com
>> > [mailto:time-nuts-boun...@febo.com] Im Auftrag von Nick Foster
>> > Gesendet: Mittwoch, 10. Februar 2010 00:41
>> > An: time-nuts@febo.com
>> > Betreff: [time-nuts] Low phase noise VCO
>> >
>> >
>> >
>> > Gentlemen,
>> >
>> > Not being an oscillator guru, I thought I'd ask here. I'm
>> > building up a fixed-frequency 64MHz PLL oscillator which uses
>> > a 10MHz reference. The reference is a homebrew HP
>> > 10544A-based GPSDO which seems to work OK. I've built a phase
>> > comparator based on a CoolRunner-II CPLD which implements a
>> > flip-flop phase-frequency comparator just like the CMOS 4046.
>> > Seems to work great, although I haven't put it to the test
>> > yet with respect to phase noise. So all I need now is the VCO.
>> >
>> > Right now, all I need is 64MHz to clock a software-defined
>> > radio, so I was thinking about using a VCXO. I see lots of
>> > solutions using LC oscillators, but very few using crystals
>> > because overtone crystals can't be pulled very far at all. So
>> > my question is, what type of oscillator would you recommend
>> > for this project, an overtone crystal oscillator like a
>> > Butler, or an LC oscillator? Is there a particular oscillator
>> > topology you favor, or (better yet) a schematic of one you like?
>> >
>> > Thanks,
>> > Nick
>> >
>> > _
>> > Hotmail: Powerful Free email with security by Microsoft.
>> > http://clk.atdmt.com/GBL/go/201469230/direct/01/
>> > ___
>> > 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.
>>
>>
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-- 
Dr. Don Latham AJ7LL
Six Mile Systems LLP
17850 Six Mile Road
POB 134
Huson, MT, 59846
VOX 406-626-4304
www.lightningforensics.com
www.sixmilesystems.com


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Re: [time-nuts] CTS TCXO

[Lux, Jim (337C)]

> -Original Message-
> From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On 
> Behalf Of Marco IK1ODO
> Sent: Wednesday, February 10, 2010 1:09 PM
> To: Discussion of precise time and frequency measurement
> Subject: [time-nuts] CTS TCXO
> 
> Hi all,
> 
> I have a CTS Knights TCXO, P/N 970-3832-0. Frequency is 10 MHz.
> Anyone knows the working voltage? Date code is from 1987, too old for
> Internet :-)
> 
> 73 - Marco IK1ODO

Why not ask CTS? 
http://www.ctscorp.com/components/

http://www.ctscorp.com/feedback/techinfo.htm


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Re: [time-nuts] Low phase noise VCO

[Bob Camp]

Hi

In general the synthesized parts are not real low noise.  You can do better 
with $5 worth of parts and some tinkering time.


Bob

--
From: "Nick Foster" 
Sent: Wednesday, February 10, 2010 4:08 PM
To: 
Subject: Re: [time-nuts] Low phase noise VCO



That's a great suggestion, Ulrich. Thanks. It took all of five minutes to 
implement in VHDL, and looks great.


I also found Fox's "Xpresso" line of miniature synthesized VCXOs, and the 
numbers look pretty compelling. CMOS output, too. And, the best part, 
they're available off-the-shelf. Does anyone have experience with these in 
low-noise applications? They're ludicrously expensive (Digikey lists them 
for $47/ea in short qty), but if I can get some samples from Fox, it'll 
save me a lot of grief.


I'll let you all know how it works out, and Don, if I get samples and they 
work OK I'll mail you some.


Nick


From: df...@ulrich-bangert.de
To: time-nuts@febo.com
Date: Wed, 10 Feb 2010 09:02:30 +0100
Subject: Re: [time-nuts] Low phase noise VCO

Nick,

altough you have been asking for advice for the VCO I would like to draw
your attention on how you can improve your phase detector. Edge-triggered
phase detectors are not bad, the even can work as frequency detectors if 
you
are far from lock and help you to gain lock where a XOR would not. 
However,

once you are CLOSE to a phase lock, a simple XOR makes the better phase
detector with less phase noise. There is a VERY easy circuit that 
marriages
the best of both worlds. Google for the AD9901 frequence/phase detector 
and
mimic their schematic of the first page into your CPLD. Have done this 
with
different CPLDS from XILINX and ALTERA and has always worked very well 
for

me in terms of frequency locking range and low phase noise.

Best regards
Ulrich Bangert

> -Ursprungliche Nachricht-
> Von: time-nuts-boun...@febo.com
> [mailto:time-nuts-boun...@febo.com] Im Auftrag von Nick Foster
> Gesendet: Mittwoch, 10. Februar 2010 00:41
> An: time-nuts@febo.com
> Betreff: [time-nuts] Low phase noise VCO
>
>
>
> Gentlemen,
>
> Not being an oscillator guru, I thought I'd ask here. I'm
> building up a fixed-frequency 64MHz PLL oscillator which uses
> a 10MHz reference. The reference is a homebrew HP
> 10544A-based GPSDO which seems to work OK. I've built a phase
> comparator based on a CoolRunner-II CPLD which implements a
> flip-flop phase-frequency comparator just like the CMOS 4046.
> Seems to work great, although I haven't put it to the test
> yet with respect to phase noise. So all I need now is the VCO.
>
> Right now, all I need is 64MHz to clock a software-defined
> radio, so I was thinking about using a VCXO. I see lots of
> solutions using LC oscillators, but very few using crystals
> because overtone crystals can't be pulled very far at all. So
> my question is, what type of oscillator would you recommend
> for this project, an overtone crystal oscillator like a
> Butler, or an LC oscillator? Is there a particular oscillator
> topology you favor, or (better yet) a schematic of one you like?
>
> Thanks,
> Nick
>
> _
> Hotmail: Powerful Free email with security by Microsoft.
> http://clk.atdmt.com/GBL/go/201469230/direct/01/
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to
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Re: [time-nuts] CTS TCXO

[George Dubovsky]

Marco,

My Stanford Research FS700 Loran receiver from about that time period has a
CTS Knights 970-2097-0 10 MHz ovenized oscillator in it, and it ran from +
and - 15 Vdc. I don't know if this is of any help at all.

73,

geo - n4ua

On Wed, Feb 10, 2010 at 4:09 PM, Marco IK1ODO  wrote:

> Hi all,
>
> I have a CTS Knights TCXO, P/N 970-3832-0. Frequency is 10 MHz.
> Anyone knows the working voltage? Date code is from 1987, too old for
> Internet :-)
>
> 73 - Marco IK1ODO
>
>
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[time-nuts] Tight PLL Tester

[WarrenS]

If there are any Nuts out there interested in helping to make available to 
other Freq-Nuts a SIMPLE tester that I have found to be a VERY useful low 
cost tool, contact me off line.

warrensjmail-...@yahoo.com

The tool is based on an OLD but seldom used method called the  "Tight 
Phase-Lock Loop Method of measuring Freq stability".
For a block diagram and short description see Figure 1.7 at 
http://tf.nist.gov/phase/Properties/one.htm#oneone


What I have made for my own use is a bread board of a simple analog version 
of  the NIST's block diagram.
There are of course many different ways to actually build it, depending on 
ones preferences, skills,  and junk box.
It can be done using a DVM, or a high or low resolution ADC, or a freq 
counter,  or counter IC chips, a Pic or any simple micro,  or a sound card, 
Or many other ways.
The nice thing about the method is that it takes no expensive or critical 
parts to get  performance as good as most anything out there.
Its main performance limitation is ONLY the single EFC OSC used as the 
reference.



My unit works  'Good enough'  to be able to test many of the things that 
Freq nuts are concerned with.
Basically it is nothing more than a high speed freq difference detector that 
can detect VERY small freq changes in a very short time.

What one then does with that data is where the flexibility comes from.
I've used mine  for AVARs plots, detecting very small freq modulation due to 
PS noise, freq offset plots, setting an osc on freq in seconds instead of 
what can take hours, GPSDO Noise and TC test,  etc. etc.   The list is 
almost endless.



Some advantages of a tight PLL method are:
1) It is very simple, cheap and easy to build, and small

2) Works well for comparing an Oscillators Freq offset, Freq Noise, Freq 
modulation,  over short time intervals


3) It provides very good sub pico Second Phase resolution even with simple 
setups.


4) Its noise floor is low enough so that its limitation is the Reference 
Osc.


5) The NIST says it can be used to one part in  1e14.  I'm getting better 
than 1e12 from it, limited by the HP10811 Ref Osc I use.


6) Would be easy to make into a PC board project for Time nuts that don't 
access to all the high end equipment.


7) I have a working breadboard that I built from just my junk box parts that 
has worked great for me for several different things


Some of its disadvantages:
1) It is not the best way to take long term phase drift differences, where a 
simple phase difference device will work great.


2) It is not a DMDT and is not as flexible in many ways, but can be just as 
accurate and a lot easier to build and less to go wrong and a whole lot 
cheaper.


3) It is basically an analog device and does not have digital accuracy. But 
for small freq differences, it is more than accurate enough to provide great 
results.


4) For those luckily enough to already have a TSC5120A or better, you don't 
need one, That is unless you want to verify its performance at short Tau.


5) And maybe the biggest disadvantage is that many of the leading Freq nuts 
on this site don't like it and seem to believe that it should not work.
But maybe that is just because they don't have one and have not even tested 
one and seem unwilling to give it any consideration.


6) A search of past post on the subject will show that many do not all agree 
that this is a good idea,
but they don't have a working unit like I do, and I don't have the expensive 
high end equipment that they have.


ws

PS
Sorry for the long post.
This is the best I can do to respond to the off line request I received to 
find a way to make this subject more useful, constructive, cooperative and 
less confrontational, and do it with less words and give more details.
I am not looking for a list of all the possible ways that it can be done 
wrong,

Or guesses on why it should not work as good as it does.
I'll leave that for others to discuss.
But if what they say does not agree with my experimental results, you can 
bet I'll still comment on it Again.

*



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Re: [time-nuts] Low phase noise VCO

[Bruce Griffiths]

Not if one uses a balun.

Bruce

Max Robinson wrote:

Bruce wrote.


A full wave rectified sinewave has only even harmonics present.


True, but it needs a center tapped coil.

Regards.

Max.  K 4 O D S.




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[time-nuts] CTS TCXO

[Marco IK1ODO]

Hi all,

I have a CTS Knights TCXO, P/N 970-3832-0. Frequency is 10 MHz.
Anyone knows the working voltage? Date code is from 1987, too old for 
Internet :-)


73 - Marco IK1ODO


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Re: [time-nuts] Low phase noise VCO

[Nick Foster]

That's a great suggestion, Ulrich. Thanks. It took all of five minutes to 
implement in VHDL, and looks great.

I also found Fox's "Xpresso" line of miniature synthesized VCXOs, and the 
numbers look pretty compelling. CMOS output, too. And, the best part, they're 
available off-the-shelf. Does anyone have experience with these in low-noise 
applications? They're ludicrously expensive (Digikey lists them for $47/ea in 
short qty), but if I can get some samples from Fox, it'll save me a lot of 
grief.

I'll let you all know how it works out, and Don, if I get samples and they work 
OK I'll mail you some.

Nick

> From: df...@ulrich-bangert.de
> To: time-nuts@febo.com
> Date: Wed, 10 Feb 2010 09:02:30 +0100
> Subject: Re: [time-nuts] Low phase noise VCO
> 
> Nick,
> 
> altough you have been asking for advice for the VCO I would like to draw
> your attention on how you can improve your phase detector. Edge-triggered
> phase detectors are not bad, the even can work as frequency detectors if you
> are far from lock and help you to gain lock where a XOR would not. However,
> once you are CLOSE to a phase lock, a simple XOR makes the better phase
> detector with less phase noise. There is a VERY easy circuit that marriages
> the best of both worlds. Google for the AD9901 frequence/phase detector and
> mimic their schematic of the first page into your CPLD. Have done this with
> different CPLDS from XILINX and ALTERA and has always worked very well for
> me in terms of frequency locking range and low phase noise.
> 
> Best regards
> Ulrich Bangert  
> 
> > -Ursprungliche Nachricht-
> > Von: time-nuts-boun...@febo.com 
> > [mailto:time-nuts-boun...@febo.com] Im Auftrag von Nick Foster
> > Gesendet: Mittwoch, 10. Februar 2010 00:41
> > An: time-nuts@febo.com
> > Betreff: [time-nuts] Low phase noise VCO
> > 
> > 
> > 
> > Gentlemen,
> > 
> > Not being an oscillator guru, I thought I'd ask here. I'm 
> > building up a fixed-frequency 64MHz PLL oscillator which uses 
> > a 10MHz reference. The reference is a homebrew HP 
> > 10544A-based GPSDO which seems to work OK. I've built a phase 
> > comparator based on a CoolRunner-II CPLD which implements a 
> > flip-flop phase-frequency comparator just like the CMOS 4046. 
> > Seems to work great, although I haven't put it to the test 
> > yet with respect to phase noise. So all I need now is the VCO.
> > 
> > Right now, all I need is 64MHz to clock a software-defined 
> > radio, so I was thinking about using a VCXO. I see lots of 
> > solutions using LC oscillators, but very few using crystals 
> > because overtone crystals can't be pulled very far at all. So 
> > my question is, what type of oscillator would you recommend 
> > for this project, an overtone crystal oscillator like a 
> > Butler, or an LC oscillator? Is there a particular oscillator 
> > topology you favor, or (better yet) a schematic of one you like?
> > 
> > Thanks,
> > Nick
> >   
> > _
> > Hotmail: Powerful Free email with security by Microsoft. 
> > http://clk.atdmt.com/GBL/go/201469230/direct/01/
> > ___
> > 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.
> 
> 
> ___
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> and follow the instructions there.
  
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Re: [time-nuts] injection locking

[Joop]

Yes, I wrote I searched for that too. This indeed is one circuit I found.

At first glance the biasing does not give me the impression it might be a
very good oscillator by itself. But then again, that might be a requirement
in order to allow it to lock to another signal.
James G1PVZ wanted to see how far he could pull it (>10% it seems). And
tested how it tracked FM modulation.

For purposes of a very pure harmonic frequency one might have to start
with a better oscillator.
I played a bit with SPICE to see if I could make a high Q oscillator lock,
but with limited success. Perhaps it needs much more time to start locking.
I guess building something and measure it might be faster.

Joop

>Joop,
>
>you may also search for "synchronous oscillator". You will find for
example:
>
>http://www.amalgamate2000.com/radio-hobbies/radio/synchronous_oscillator.htm
>
>Best regards
>Ulrich
>
>> -Ursprungliche Nachricht-
>> Von: time-nuts-bounces at febo.com 
>> [mailto:time-nuts-bounces at febo.com] Im Auftrag von Joop
>> Gesendet: Mittwoch, 10. Februar 2010 13:50
>> An: time-nuts at febo.com
>> Betreff: [time-nuts] injection locking
>> 
>> 
>> >You can even build an injection locked divide by 5 stage. 
>> Choosing the 
>> >right oscillator topology and injection method allows high level 
>> >injection to be used with an LC oscillator.
>> >
>> >Bruce
>> >
>> 
>> Are there references to some practical circuits? That would be great.
>> 
>> A google search on "injection locking" and "synchronous 
>> oscillator" results in a lot of conceptual descriptions but 
>> nothing that one can build, try out and study. Maybe some of 
>> the scientific articles or books contain circuits, but I am 
>> not a IEEE member.
>> 
>> Cheers,
>> Joop
>

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Re: [time-nuts] 5065A Problem

[John Miles]

True, photo current should still be present if you have cell flooding.  Only
the second harmonic would be affected by that.  Amplitude should be stable
immediately after power-up, so my guess is there's a supply regulation
problem.  Check the supply voltage to the OCXO, and if OK, check the output
level at the oscillator itself?

-- john, KE5FX

> -Original Message-
> From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com]on
> Behalf Of J. L. Trantham
> Sent: Wednesday, February 10, 2010 6:10 AM
> To: 'Discussion of precise time and frequency measurement'
> Subject: Re: [time-nuts] 5065A Problem
>
>
> John,
>
> Thanks for the reply.
>
> I don't know the history, just got it.  When first plugged in, Photo I and
> 2nd Harmonic go full scale then promptly come back to 0 (center).  Supply
> indicates normally, Lamp Oven, Cell Oven and Osc Oven all go full
> scale and
> stay. After about 20 to 30 minutes, they come back on scale and seem to
> indicate normally as compared to what the manual says.  5 MHz indicates
> normally though it takes a few minutes for it to 'warm up' to the proper
> amplitude.  1 MHz and 100 kHz do not indicate when the Start switch is
> cycled until after 30 or 40 minutes of warm up.  Then they come on scale
> normally.  When hooked to a scope, at 50 ohms, their amplitude essentially
> disappears.  I suspect a problem there.  Still visible at 1 Meg input
> impedance.  Control and Error stay at 0.  So, I think all indications are
> normal except Photo I and 2nd Harmonic.
>
> I read about the cell flooding issue and how to deal with it in the manual
> but I was expecting Photo I to give an indication in the presence of cell
> flooding.  Should there be an indication on Photo I in the
> presence of cell
> flooding?  If not, then clearly I need to go through the cell flooding
> steps.
>
> J16 indicates about 19.987 VDC  I did not measure the current at
> J16.  I'll
> have to go back and do that.
>
> Joe
>
>
>
> -Original Message-
> From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
> Behalf Of John Miles
> Sent: Tuesday, February 09, 2010 11:51 PM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] 5065A Problem
>
>
> Suggestions:
>
> 1) Was it working before?  If not you may need to follow the cell-flooding
> correction procedure in the manual.  Corby Dawson made an informative post
> about that phenomenon a couple of years ago, if you can find it in the
> archives.
>
> 2) If it was working but failed, check the +20V supply at J16
> first.  If the
> voltage at that jack is OK but no current is being drawn, the Colpitts
> oscillator that drives the lamp has failed.  Nothing else will work until
> you open the RVFR and fix the oscillator -- which is possible but not much
> fun.
>
> Suggest checking the ESR of all of the capacitors on the A11 oven
> controller
> before you put it back into service.  When I got my 5065A I had
> to replace a
> resistor on the oscillator board that had physically cracked from
> overheating.  Both C23 and C24 on A11 were open; so were the same two 20
> uF/50V capacitors on the battery-charger board.
>
> I don't immediately see how that could have caused the oven controller to
> run away, but it was pretty clear that it had happened at some
> point. Either
> way, if the lamp or cell oven current hasn't decreased within
> 20-30 minutes
> after turnon, you need to power it down and look for a controller problem.
>
> -- john, KE5FX
>
>
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Re: [time-nuts] injection locking

[Don Latham]

Hi Ulrich and all, you kicked up an old memory. In the early 1960's a
friend and I messed some with nuclear magnetic resonance and synchronous
oscillators for detection of same. Later found a nice paper:
Uzunoglu and White, IEEE Journal of Solid-State Circuits V. SC-20,#6,
Dec.1985, p.1214-1226. Has substantially the same circuit as the web page
someone noted earlier, and a lot of analysis. Basically, the problems are
the same as lock-in, the fight being between essentialy the Q of the
locking circuit and lock time and so forth.
Interesting; when the time comes for the 64 MHz oscillator I'll try it!
Don



Ulrich Bangert
> Joop,
>
> you may also search for "synchronous oscillator". You will find for
> example:
>
> http://www.amalgamate2000.com/radio-hobbies/radio/synchronous_oscillator.htm
>
> Best regards
> Ulrich
>
>> -Ursprungliche Nachricht-
>> Von: time-nuts-boun...@febo.com
>> [mailto:time-nuts-boun...@febo.com] Im Auftrag von Joop
>> Gesendet: Mittwoch, 10. Februar 2010 13:50
>> An: time-nuts@febo.com
>> Betreff: [time-nuts] injection locking
>>
>>
>> >You can even build an injection locked divide by 5 stage.
>> Choosing the
>> >right oscillator topology and injection method allows high level
>> >injection to be used with an LC oscillator.
>> >
>> >Bruce
>> >
>>
>> Are there references to some practical circuits? That would be great.
>>
>> A google search on "injection locking" and "synchronous
>> oscillator" results in a lot of conceptual descriptions but
>> nothing that one can build, try out and study. Maybe some of
>> the scientific articles or books contain circuits, but I am
>> not a IEEE member.
>>
>> Cheers,
>> Joop
>>
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>
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-- 
Dr. Don Latham AJ7LL
Six Mile Systems LLP
17850 Six Mile Road
POB 134
Huson, MT, 59846
VOX 406-626-4304
www.lightningforensics.com
www.sixmilesystems.com


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Re: [time-nuts] Low phase noise VCO

[Max Robinson]

Bruce wrote.


A full wave rectified sinewave has only even harmonics present.


True, but it needs a center tapped coil.

Regards.

Max.  K 4 O D S.

Email: m...@maxsmusicplace.com

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- Original Message - 
From: "Bruce Griffiths" 
To: "Discussion of precise time and frequency measurement" 


Sent: Tuesday, February 09, 2010 7:25 PM
Subject: Re: [time-nuts] Low phase noise VCO



A full wave rectified sinewave has only even harmonics present.

Bruce

Max Robinson wrote:

If you start with a square wave odd order is all you can get but if
you start with a pulse with a 25% duty cycle you can get even order.
It's best to optimize the pulse width for the harmonic you want.

Regards.

Max.  K 4 O D S.

Email: m...@maxsmusicplace.com

Transistor site http://www.funwithtransistors.net
Vacuum tube site: http://www.funwithtubes.net
Music site: http://www.maxsmusicplace.com

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- Original Message - From: "Nick Foster" 
To: 
Sent: Tuesday, February 09, 2010 6:35 PM
Subject: Re: [time-nuts] Low phase noise VCO





From: b...@iaxs.net
To: time-nuts@febo.com
Date: Tue, 9 Feb 2010 18:24:39 -0600
Subject: Re: [time-nuts] Low phase noise VCO

Which leads me to ask a novice question:

Why not pull a 16 MHz crystal and multiply to 64 MHz?

If you count down from 64 to 10 MHz, isn't the multiplication inside
the
PLL?

Perhaps the noise is multiplied by 4, but would it work for the
intended
purpose?

Bill Hawkins


Can you do x4 multipliers? I thought odd-order harmonics were usually
used for multipliers. I'd be happy to be wrong!

Nick

_




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No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 8.5.435 / Virus Database: 271.1.1/2679 - Release Date: 02/10/10 
07:40:00



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Re: [time-nuts] HP K04 59991A Frequency multiplier comparator

[Corby Dawson]

BOB,

It was one of the "special" custom built units by HP not listed in the
catalogs.

Corby

Weight Loss Program
Best Weight Loss Program - Click Here!
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Re: [time-nuts] injection locking

[Ulrich Bangert]

Joop,

you may also search for "synchronous oscillator". You will find for example:

http://www.amalgamate2000.com/radio-hobbies/radio/synchronous_oscillator.htm

Best regards
Ulrich

> -Ursprungliche Nachricht-
> Von: time-nuts-boun...@febo.com 
> [mailto:time-nuts-boun...@febo.com] Im Auftrag von Joop
> Gesendet: Mittwoch, 10. Februar 2010 13:50
> An: time-nuts@febo.com
> Betreff: [time-nuts] injection locking
> 
> 
> >You can even build an injection locked divide by 5 stage. 
> Choosing the 
> >right oscillator topology and injection method allows high level 
> >injection to be used with an LC oscillator.
> >
> >Bruce
> >
> 
> Are there references to some practical circuits? That would be great.
> 
> A google search on "injection locking" and "synchronous 
> oscillator" results in a lot of conceptual descriptions but 
> nothing that one can build, try out and study. Maybe some of 
> the scientific articles or books contain circuits, but I am 
> not a IEEE member.
> 
> Cheers,
> Joop
> 
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Re: [time-nuts] New Heather code

[Mark Sims]

Hello Raj,You should leave the tbolt coordinates set to the WGS84 coordinates 
that the receiver determines and not what a surveyor might come up with (which 
will probably be in some coordinate system offset from WGS84).Also the latest 
version of the Lady Heather beta program just uploaded to John's site 
(http://www.ke5fx.com/heather/beta.exe)  has a new feature that might come in 
handy in India.  You can display the date in one of several calendar systems 
(including the  Indian civil calendar,  hebrew, islamic,  persian,  mayan,  
aztec,  druid,  etc)

Another useful feature is an antenna signal level survey map.  To use it,  set 
the antenna elevation mask to 0 degrees (from the F)ilter menu and select one 
of the survey maps from the S)urvey menu.   It needs 24 hours of data to get a 
good map.  You can zoom the maps (or the clock displays) to full screen with 
the Z command.  Any key returns the screen to normal mode.  To dump a full 
screen display to a file use the '\' command that writes tbolt.gif without 
prompting for a file name. 
_
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Re: [time-nuts] injection locking

[Gerhard Hoffmann]

Bob Camp wrote:

> That's the problem.
There's no debate that you can injection lock oscillators. The problem is that the analytic side of designing an injection lock system  is a bit lacking. 
  
Rohde has in [1] a deluge of math on mutually coupled resonators and 
oscillators,
including noise analysis  - and injection locking is just a special case 
thereof.




[¹] Ulrich L. Rohde, Ajay K. Poddar, Georg Böck
THe Design of Modern Microwave Oscillators for Wireless Applications
Theory & Optimization
Wiley
isbn 0-471-72342-8

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Re: [time-nuts] injection locking

[Bob Camp]

Hi

That's the problem. 

There's no debate that you can injection lock oscillators. The problem is that 
the analytic side of designing an injection lock system  is a bit lacking. 

With a PLL there's an over abundance of information on how to do the design, 
how to analyze it, and how to test it. You can optimize loop bandwidth, phase 
margin, noise performance, and component selection. A paper design pretty is 
going to be a pretty good start on a working circuit.  There are an over 
abundance of free tools to do a design with. 

Again, the point is not weather one works and the other does not. They both 
work. There's just a *whole* lot more stuff out there on PLL's.

PLL chips are dirt cheap ($1 ~ $2 for most). Even a PIC to set them up is sub 
$1. They do have limits and you need to understand those limits. If you can get 
the job done with one, it's a simple way to go. 

Bob


On Feb 10, 2010, at 7:50 AM, Joop wrote:

>> You can even build an injection locked divide by 5 stage.
>> Choosing the right oscillator topology and injection method allows high 
>> level injection to be used with an LC oscillator.
>> 
>> Bruce
>> 
> 
> Are there references to some practical circuits? That would be great.
> 
> A google search on "injection locking" and "synchronous oscillator"
> results in a lot of conceptual descriptions but nothing that one can build,
> try out and study. Maybe some of the scientific articles or books contain
> circuits, but I am not a IEEE member.
> 
> Cheers,
> Joop
> 
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> 


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Re: [time-nuts] TBolt self survey

[Stan, W1LE]

Hello Arnold,

Thanks for that pointer, the height calculator works out nicely.

for my location I estimated height above mean sea level as
235' (ground level) + 10' (height of the tripod and mast to the GPS puck 
antenna)

or an estimate of 245' ASL.

The calculator shows:

Your Input Coordinates and GPS Height:

Latitude = 41.72877° N = 41° 43' 43.57" N
Longitude = 70.4642° W = 70° 27' 51.12" W
GPS ellipsoidal height = 47.915 (meters)
Geoid height = -29.190 (meters)
Orthometric height (height above mean sea level) = 77.105 (meters)
(note: orthometric Height = GPS ellipsoidal height - geoid height)


77.105 meters = 252.969'

As a (microwave) ham, I will always take the extra height.

Stan, W1LE Cape Cod FN41sr





Arnold Tibus wrote:

Try to find your correct height here:
http://sps.unavco.org/geoid/

  




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Re: [time-nuts] any WWV audio recordings available?

[Scott Burris]

Thanks for all the pointers.

I've come to a new intense dislike of electrolytic capacitors while debugging my
clock.  One was really bad in the radio receiver board's AGC circuit, causing 
oscillation,
so I ended up recaping every electrolytic I could find.  Probably not too 
surprising in
a 20+ year old clock.

The clock stopped syncing about 5 months ago.  I did the cap replacement, then
realigned the receiver and tone decoders, but still no go.  That's why I was 
trying to
cut my problem space in half by injecting a known good audio.  I thought it
would be a no brainer for the clock to sync to injected audio, but that hasn't 
gone
as well as expected.

The clock isn't a source of time or frequency for me anymore, but I want to 
keep it
alive for the nostalgia factor.

Scott


On Feb 9, 2010, at 11:26 PM, Dean Weiten wrote:

> Hi there,
> 
> Some time ago, I "hot rodded" the "tg" program that comes with the open
> source "ntp" package and cleaned it up, making options for different
> output formats, including IEEE 1344 extensions on the IRIG, and cleaned
> up the WWV output for DST shifts, quality coding, etc.
> 
> When you posted your question, I did a quick look, hacked in libsndfile
> calls, and made it so it can generate clean IRIG-B or WWV audio WAV
> files of arbitrary duration, starting at arbitrary times.  The
> generation actually runs much faster than real time, resulting in huge
> files for long time frames, stored in seconds.
> 
> As an example, please find at
> http://www.weiten.com/time_nuts/2010-02-10_07h09Z.zip , a 221k ZIP
> archive that expands out to a 92M WAV file of simulated WWV audio from
> 2010-02-10 07h10Z to about 17h29Z.
> 
> Is this helpful?
> 
> -- 
> 
> Dean Weiten
> Phone:(204)-888-1334 (home)
>  (204)-771-4925 (cell)
> E-mail:   d...@weiten.com (home)
> 
> 
> 
> 
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Re: [time-nuts] 5065A Problem

[J. L. Trantham]

John,

Thanks for the reply.

I don't know the history, just got it.  When first plugged in, Photo I and
2nd Harmonic go full scale then promptly come back to 0 (center).  Supply
indicates normally, Lamp Oven, Cell Oven and Osc Oven all go full scale and
stay. After about 20 to 30 minutes, they come back on scale and seem to
indicate normally as compared to what the manual says.  5 MHz indicates
normally though it takes a few minutes for it to 'warm up' to the proper
amplitude.  1 MHz and 100 kHz do not indicate when the Start switch is
cycled until after 30 or 40 minutes of warm up.  Then they come on scale
normally.  When hooked to a scope, at 50 ohms, their amplitude essentially
disappears.  I suspect a problem there.  Still visible at 1 Meg input
impedance.  Control and Error stay at 0.  So, I think all indications are
normal except Photo I and 2nd Harmonic.

I read about the cell flooding issue and how to deal with it in the manual
but I was expecting Photo I to give an indication in the presence of cell
flooding.  Should there be an indication on Photo I in the presence of cell
flooding?  If not, then clearly I need to go through the cell flooding
steps.

J16 indicates about 19.987 VDC  I did not measure the current at J16.  I'll
have to go back and do that.

Joe



-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of John Miles
Sent: Tuesday, February 09, 2010 11:51 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] 5065A Problem


Suggestions:

1) Was it working before?  If not you may need to follow the cell-flooding
correction procedure in the manual.  Corby Dawson made an informative post
about that phenomenon a couple of years ago, if you can find it in the
archives.

2) If it was working but failed, check the +20V supply at J16 first.  If the
voltage at that jack is OK but no current is being drawn, the Colpitts
oscillator that drives the lamp has failed.  Nothing else will work until
you open the RVFR and fix the oscillator -- which is possible but not much
fun.

Suggest checking the ESR of all of the capacitors on the A11 oven controller
before you put it back into service.  When I got my 5065A I had to replace a
resistor on the oscillator board that had physically cracked from
overheating.  Both C23 and C24 on A11 were open; so were the same two 20
uF/50V capacitors on the battery-charger board.

I don't immediately see how that could have caused the oven controller to
run away, but it was pretty clear that it had happened at some point. Either
way, if the lamp or cell oven current hasn't decreased within 20-30 minutes
after turnon, you need to power it down and look for a controller problem.

-- john, KE5FX


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Re: [time-nuts] TBolt self survey

[Arnold Tibus]

Try to find your correct height here:
http://sps.unavco.org/geoid/

If you put in your correct coordinates without any input for the elevation, 
you will get theorthometric height, which is the GPS ellipsoidal height 
minus geoid height. That is the amount you need to subtract from 
your Thunderbolt GPS height in order to get your local geodetic height 
(WGS84). 

Filling in the Thunderbolt GPS height you will get the 'real' height 
for your antenna...

Some explanations:
http://www.unavco.org/edu_outreach/tutorial/geoidcorr.html

On my location I have always to reduce the GPS height by 46.623 m.
Good luck with TB and the Lady Heather,

Arnold, DK2WT



On Wed, 10 Feb 2010 14:20:36 +0100, EB4APL wrote:

>Raj,

>Ask them about ellipsoidal and orthometric heights, or the local 
>difference between the geoid and the WGS84 ellipsoid.  Also your long 
>and lat may change depending of the Geodetic Reference System chosen.  
>By default GPS receivers use WGS84 and ellipsoidal height.

>73 de Ignacio, EB4APL

>--
>Raj wrote:
>> Thanks Stan,
>>
>> That worked, I did not see the  control menu properly!
>>
>> I set the co-ords to 0 0 0 and started survey. The Tbolt found the Lat long 
>> withing a few minutes and only the altitude is about 70 M below the official 
>> figure for my place. I live a a few hundred meters from Bangalore center and 
>> I am at the same height.. must check with the survey dept. down the road!!
>>
>> 73
>> Raj vu2zap
>>
>>
>> At 10-02-10, you wrote:
>>   
>>> Hello Raj,
>>>
>>> using the trimble T'boltMON software:
>>>
>>> Start with a "factory reset" in the control menu
>>>
>>> follow previous guidance of enabling the "save position" capability,
>>>
>>> Then to restart a survey
>>>
>>> go to the control menu (on left),
>>> select "restart self survey"
>>>
>>>
>>> In lady Heather V3.0 beta of 21 Jan '10 ( available from the KE5FX website):
>>> keyboard enter a "s", for survey
>>> then "s" for a standard survey,
>>> use the default of 2000 samples,  for a start
>>> Then "enter"
>>>
>>> Time for me to go to bed.
>>>
>>> Please advise of progress.
>>>
>>> Stan,  W1LE
>>>
>>>
>>> Raj wrote:
>>> 
 Thanks Stan,

 I did that but I can't where to "start the survey" in TBolt. In lady 
 heather there
 is a key for it.

 At 09-02-10, you wrote:
  
   
> Hello Raj,
>
> that location is probably where the coordinates were last saved. or there 
> abouts
> Or those are the default factory settings from memory,
> and new coordinates were never saved.
>
> redo the survey and save the results.
>
> using T'boltMON V2.60 on a PC:
>
> go to menu "set up",  then "self survey",   click on the "save position 
> flag"
> then "set survey",
> then "save segment",
> then "close"
>
> redo the survey and afterwards verify the local coordinates were saved.
>
> Lady Heather (software) can also be utilzed for these functions.
>
> Any problems, please advise.
>
> Stan, W1LE
>
>
>
> Raj wrote:
>
> 
>>   Can someone point me to info that would clarify why my Tbolt's 
>> self survey puts my house (AFAIK ~920M ASL, 13N 77.35E) in the Pacific 
>> ocean, south of Vancouver and west of Seattle and about 10 meters under 
>> water. I am doing something wrong for sure!
>>
>>   My sons iPhone gives me right co-ordinates but it's way off the 
>> altitude.
>>   
>> Regards
>>   




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Re: [time-nuts] TBolt self survey

[EB4APL]

Raj,

Ask them about ellipsoidal and orthometric heights, or the local 
difference between the geoid and the WGS84 ellipsoid.  Also your long 
and lat may change depending of the Geodetic Reference System chosen.  
By default GPS receivers use WGS84 and ellipsoidal height.


73 de Ignacio, EB4APL

--
Raj wrote:

Thanks Stan,

That worked, I did not see the  control menu properly!

I set the co-ords to 0 0 0 and started survey. The Tbolt found the Lat long 
withing a few minutes and only the altitude is about 70 M below the official 
figure for my place. I live a a few hundred meters from Bangalore center and I 
am at the same height.. must check with the survey dept. down the road!!

73
Raj vu2zap


At 10-02-10, you wrote:
  

Hello Raj,

using the trimble T'boltMON software:

Start with a "factory reset" in the control menu

follow previous guidance of enabling the "save position" capability,

Then to restart a survey

go to the control menu (on left),
select "restart self survey"


In lady Heather V3.0 beta of 21 Jan '10 ( available from the KE5FX website):
keyboard enter a "s", for survey
then "s" for a standard survey,
use the default of 2000 samples,  for a start
Then "enter"

Time for me to go to bed.

Please advise of progress.

Stan,  W1LE


Raj wrote:


Thanks Stan,

I did that but I can't where to "start the survey" in TBolt. In lady heather 
there
is a key for it.

At 09-02-10, you wrote:
 
  

Hello Raj,

that location is probably where the coordinates were last saved. or there 
abouts
Or those are the default factory settings from memory,
and new coordinates were never saved.

redo the survey and save the results.

using T'boltMON V2.60 on a PC:

go to menu "set up",  then "self survey",   click on the "save position flag"
then "set survey",
then "save segment",
then "close"

redo the survey and afterwards verify the local coordinates were saved.

Lady Heather (software) can also be utilzed for these functions.

Any problems, please advise.

Stan, W1LE



Raj wrote:
   


  Can someone point me to info that would clarify why my Tbolt's self 
survey puts my house (AFAIK ~920M ASL, 13N 77.35E) in the Pacific ocean, south 
of Vancouver and west of Seattle and about 10 meters under water. I am doing 
something wrong for sure!

  My sons iPhone gives me right co-ordinates but it's way off the altitude.
  
Regards
  


  



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Re: [time-nuts] TBolt self survey

[Raj]

Thanks Stan,

That worked, I did not see the  control menu properly!

I set the co-ords to 0 0 0 and started survey. The Tbolt found the Lat long 
withing a few minutes and only the altitude is about 70 M below the official 
figure for my place. I live a a few hundred meters from Bangalore center and I 
am at the same height.. must check with the survey dept. down the road!!

73
Raj vu2zap


At 10-02-10, you wrote:
>Hello Raj,
>
>using the trimble T'boltMON software:
>
>Start with a "factory reset" in the control menu
>
>follow previous guidance of enabling the "save position" capability,
>
>Then to restart a survey
>
>go to the control menu (on left),
>select "restart self survey"
>
>
>In lady Heather V3.0 beta of 21 Jan '10 ( available from the KE5FX website):
>keyboard enter a "s", for survey
>then "s" for a standard survey,
>use the default of 2000 samples,  for a start
>Then "enter"
>
>Time for me to go to bed.
>
>Please advise of progress.
>
>Stan,  W1LE
>
>
>Raj wrote:
>>Thanks Stan,
>>
>>I did that but I can't where to "start the survey" in TBolt. In lady heather 
>>there
>>is a key for it.
>>
>>At 09-02-10, you wrote:
>>  
>>>Hello Raj,
>>>
>>>that location is probably where the coordinates were last saved. or there 
>>>abouts
>>>Or those are the default factory settings from memory,
>>>and new coordinates were never saved.
>>>
>>>redo the survey and save the results.
>>>
>>>using T'boltMON V2.60 on a PC:
>>>
>>>go to menu "set up",  then "self survey",   click on the "save position flag"
>>>then "set survey",
>>>then "save segment",
>>>then "close"
>>>
>>>redo the survey and afterwards verify the local coordinates were saved.
>>>
>>>Lady Heather (software) can also be utilzed for these functions.
>>>
>>>Any problems, please advise.
>>>
>>>Stan, W1LE
>>>
>>>
>>>
>>>Raj wrote:
>>>
   Can someone point me to info that would clarify why my Tbolt's self 
 survey puts my house (AFAIK ~920M ASL, 13N 77.35E) in the Pacific ocean, 
 south of Vancouver and west of Seattle and about 10 meters under water. I 
 am doing something wrong for sure!

   My sons iPhone gives me right co-ordinates but it's way off the 
 altitude.
   
Regards

-- 
Raj, VU2ZAP
Bangalore, India. 


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[time-nuts] injection locking

[Joop]

>You can even build an injection locked divide by 5 stage.
>Choosing the right oscillator topology and injection method allows high 
>level injection to be used with an LC oscillator.
>
>Bruce
>

Are there references to some practical circuits? That would be great.

A google search on "injection locking" and "synchronous oscillator"
results in a lot of conceptual descriptions but nothing that one can build,
try out and study. Maybe some of the scientific articles or books contain
circuits, but I am not a IEEE member.

Cheers,
Joop

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Re: [time-nuts] Low phase noise VCO

[Bob Camp]

Hi

A good 64 MHz VCXO should have *better* phase noise at 100 Hz than the 
multiplied 10 MHz out of a GPSDO. Even if you don't hit "state of the art" at 
100 Hz, it will be better past a few hundred Hz. 

A narrow loop is just fine. 

If the bandwidth gets to wide, you have to start worrying about the noise floor 
of the dividers and the phase detectors. With a narrow loop, a $1 or $2 all in 
one PLL / divider chip will do just fine. If you try to lock up something 
that's got -160 dbc/hz on a 10 MHz reference, that's not going to be the case.

If you are building a VCXO from scratch, build more than one. Set up a simple 
quadrature / mixer / sound card phase noise tester. If you already have a good 
sound card, the rest of it is a sub $100 investment. Then you will know what 
you have.

Bob 


On Feb 10, 2010, at 12:36 AM, Nick Foster wrote:

> 
> You're right, it's for a USRP. I just got annoyed with the constant frequency 
> offset, so I'm rolling my own. Turns out there isn't much available for good 
> off-the-shelf 64MHz VCXOs. The USRP2 has built-in support for 10MHz sync, but 
> not having one, I'm left to what I do have. Can't injection lock the 
> oscillator on board, as it's a self-contained square-wave clock. So it looks 
> like I'm going to try my hand at a Butler VCXO.
> 
> That said, I know that for PLLs, the maximum control loop bandwidth you can 
> use is limited by the pullability of your oscillator: if you use a VCXO with 
> very low Kv, you might end up with a maximum useful loop bandwidth of 10Hz. 
> No sense in using a 10544A to tune that! The phase noise performance would be 
> pretty awful, since you can't tightly lock the reference oscillator to it. So 
> does it make more sense to use a high-Q LC oscillator instead, with a much 
> higher Kv? I'd be able to phase-lock it much more tightly to the reference 
> oscillator. Plus, a 64MHz LC oscillator is pretty easy to build.
> 
> 
> --n
> 
>> Date: Tue, 9 Feb 2010 21:50:57 -0700
>> From: d...@montana.com
>> To: time-nuts@febo.com
>> Subject: Re: [time-nuts] Low phase noise VCO
>> 
>> Hi Bob and all:
>> This is interesting, because I suspect this frequency source is for an
>> Ettus Research USRP. A little further downtimeline I will be faced with
>> this problem as well. The SDR is designed already and requires a 64 MHz
>> clock, especially as this clock is used for the microwave transmit and
>> receive front ends. I had planned a synthesizer filtered...
>> The oscillator that is in the USRP that I have is good only to about 1
>> part in 10^8 or so for accuracy, better in stability. maybe the existing
>> osc. can be injection locked, or temp controlled in place.
>> Don
>> 
>> Bob Camp
>>> Hi
>>> 
>>> With most SDR's a spur on the clock creates a spur in the radio. No matter
>>> how you do your multiply, you will wind up with some sub-harmonics running
>>> around. Much better / easier / quicker to start at 64 or 65 MHz.
>>> 
>>> Bob
>>> 
>>> 
>>> On Feb 9, 2010, at 8:32 PM, Bruce Griffiths wrote:
>>> 
 Thats not very useful when you want the 4th harmonic as its amplitude is
 zero fro a 25% duty cycle.
 Using a duty cycle of 1/8, 3/8 or 5/8 will maximise the amplitude of the
 4th harmonic.
 
 see:
 http://www.wenzel.com/pdffiles1/pdfs/choose.pdf
 
 Bruce
 
 Max Robinson wrote:
> If you start with a square wave odd order is all you can get but if you
> start with a pulse with a 25% duty cycle you can get even order.  It's
> best to optimize the pulse width for the harmonic you want.
> 
> Regards.
> 
> Max.  K 4 O D S.
> 
> Email: m...@maxsmusicplace.com
> 
> Transistor site http://www.funwithtransistors.net
> Vacuum tube site: http://www.funwithtubes.net
> Music site: http://www.maxsmusicplace.com
> 
> To subscribe to the fun with transistors group send an email to.
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> 
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> funwithtubes-subscr...@yahoogroups.com
> 
> - Original Message - From: "Nick Foster"
> 
> To: 
> Sent: Tuesday, February 09, 2010 6:35 PM
> Subject: Re: [time-nuts] Low phase noise VCO
> 
> 
>> 
>>> From: b...@iaxs.net
>>> To: time-nuts@febo.com
>>> Date: Tue, 9 Feb 2010 18:24:39 -0600
>>> Subject: Re: [time-nuts] Low phase noise VCO
>>> 
>>> Which leads me to ask a novice question:
>>> 
>>> Why not pull a 16 MHz crystal and multiply to 64 MHz?
>>> 
>>> If you count down from 64 to 10 MHz, isn't the multiplication inside
>>> the
>>> PLL?
>>> 
>>> Perhaps the noise is multiplied by 4, but would it work for the
>>> intended
>>> purpose?
>>> 
>>> Bill Hawkins
>> 
>> Can you do x4 multipliers? I thought odd-order harmonics were usually
>> used for multipliers. I'd be happy to be wrong!
>> 
>> Nick
>> 
 
 
>

Re: [time-nuts] any WWV audio recordings available?

[Eamon Skelton]

Scott Burris wrote:

Does anyone know if there are any > 5min recordings of WWV audio available?


http://www.youtube.com/watch?v=9CpsPgXyIm8


--
Linux 2.6.30


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Re: [time-nuts] Low phase noise VCO

[Ulrich Bangert]

Nick,

altough you have been asking for advice for the VCO I would like to draw
your attention on how you can improve your phase detector. Edge-triggered
phase detectors are not bad, the even can work as frequency detectors if you
are far from lock and help you to gain lock where a XOR would not. However,
once you are CLOSE to a phase lock, a simple XOR makes the better phase
detector with less phase noise. There is a VERY easy circuit that marriages
the best of both worlds. Google for the AD9901 frequence/phase detector and
mimic their schematic of the first page into your CPLD. Have done this with
different CPLDS from XILINX and ALTERA and has always worked very well for
me in terms of frequency locking range and low phase noise.

Best regards
Ulrich Bangert  

> -Ursprungliche Nachricht-
> Von: time-nuts-boun...@febo.com 
> [mailto:time-nuts-boun...@febo.com] Im Auftrag von Nick Foster
> Gesendet: Mittwoch, 10. Februar 2010 00:41
> An: time-nuts@febo.com
> Betreff: [time-nuts] Low phase noise VCO
> 
> 
> 
> Gentlemen,
> 
> Not being an oscillator guru, I thought I'd ask here. I'm 
> building up a fixed-frequency 64MHz PLL oscillator which uses 
> a 10MHz reference. The reference is a homebrew HP 
> 10544A-based GPSDO which seems to work OK. I've built a phase 
> comparator based on a CoolRunner-II CPLD which implements a 
> flip-flop phase-frequency comparator just like the CMOS 4046. 
> Seems to work great, although I haven't put it to the test 
> yet with respect to phase noise. So all I need now is the VCO.
> 
> Right now, all I need is 64MHz to clock a software-defined 
> radio, so I was thinking about using a VCXO. I see lots of 
> solutions using LC oscillators, but very few using crystals 
> because overtone crystals can't be pulled very far at all. So 
> my question is, what type of oscillator would you recommend 
> for this project, an overtone crystal oscillator like a 
> Butler, or an LC oscillator? Is there a particular oscillator 
> topology you favor, or (better yet) a schematic of one you like?
> 
> Thanks,
> Nick
> 
> _
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