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

[Charles Steinmetz]

Tim wrote:


If you want to make it time-nutty, there's the NIST JFET "push-push"
frequency doubler we've talked about here in the past.


As I noted during the push-push doubler discussion, a push-push FET 
doubler works much better if one does not run the FETs to cutoff.  This 
is because the FETs do not operate as switches, but rather as 
common-base amplifiers.  Running them into cutoff does nothing except 
generate large amounts of undesired odd-order and higher even-order 
harmonics in addition to the desired second harmonic.


I posted a schematic with graphs, comments, and discussion on Didier's site:

.

The on-list discussion is included.

The posted design focuses on doubling 5MHz to 10MHz, but I tested the 
prototype with 50MHz input (100MHz output) using J310s and 2N4416s, and 
it worked fine.


Best regards.

Charles


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

[Will Kimber]

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


Will..


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

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

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

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

Tim N3QE

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


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

116 + 28 = 144
116 + 30 = 146

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

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

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

Dave
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Re: [time-nuts] Timelab and the 53220A - getting best results

[Nick Sayer via time-nuts]

The 1 PPS outputs come directly from the GPS modules, so they’re not 
interesting for me. I’m trying to evaluate the oscillators post-discipline.

I think the datasheet for the 53220A implies that no-dead-time measurement is a 
value-add feature that the 53220A lacks. If I were going to upgrade, it would 
be to a TimePod, but I can’t justify that today.

I have discovered the data logging feature, but the problem now is that it 
doesn’t tell me what the sample time is. It appears the solution to that is to 
simply divide the run time by the sample count. I’ve got a run going now and am 
going to try that.

I could just go back to straight frequency counting, but then I have two 
quantities - gate time and sample rate (where 1/sample rate > gate time). For 
example, with a gate time of 0.5s, I get a sample time of around 0.75s or so 
(caused by the over-the-network acquisition method used by TimeLab). Is that 
reducing my acuity unduly?


> On May 29, 2016, at 10:34 PM, Anders Wallin  
> wrote:
> 
> A time-interval measurement between 1-PPS outputs of your two clocks is the 
> most straightforward to interpret.
> With the 20ps 53230A I get a noise-floor of about 1.8e-11/tau(s) for this 
> measurement. 
> I haven't tried the 100ps version, I suspect the hardware is identical and 
> HPAK just de-rates the spec/firmware to 100ps in order to 'segment the 
> market'.
> 
> In frequency counting mode things are tricky because it does some sort of 
> omega-counting in default (CONT) mode.
> This makes the effective bandwidth depend on the gate-time. (see 2nd image of 
> 2nd link).
> The pi-counting mode is called RCON and is undocumented AFAIK. I got 
> 3e-11/tau(s) with a 1s gate time and here I would expect noise-floor 
> measurements to fall on this same line independent of gate time (I haven't 
> verified this).
> 
> http://www.anderswallin.net/2015/06/cont-vs-rcon-mode-on-the-53230a-frequency-counter/
> http://www.anderswallin.net/2015/04/keysight-53230a-noise-floor-test/
> 
> Anders
> 
> 
> On Sat, May 28, 2016 at 7:11 PM, Nick Sayer via time-nuts 
>  wrote:
> So far, I’ve been configuring my 53220A for frequency measurements with a 500 
> msec gate time, and using the external reference and one input.
> 
> If instead I send the two devices into inputs A and B, and ask for the time 
> interval between the two and give that to Timelab, my results look quite a 
> bit worse.
> 
> At the moment, I’m doing that with a pair of 5680As. The ADEV at 100s is 
> reasonably close to the spec at 1.83E-12, but the tau at 10s is what it’s 
> *supposed* to be at 1s: 1.43E-11. At 1s, it’s 1.42E-10. The line is quite 
> linear between those points, but the slope is way off the spec. The frequency 
> difference graph supports this view - it shows a ±2E-10 “haze.”
> 
> I don’t have any reason to believe either oscillator is misbehaving to an 
> extent that would explain this. I’m fairly sure I’m making some kind of 
> fundamental newbie mistake and the test setup is introducing some sort of 
> error, or I’m inside of the uncertainty of the 53220A and that’s why it’s 
> showing poorly at low tau. My money is on the former. :)
> 
> The behavior I see suggests that how Timelab works with the 53220A is that it 
> sends a command to obtain a single measurement over and over again. Thus, the 
> network latency figures into the measurement timespan, I think. I’m sure 
> there’s a way to record measurements in the 53220A internally and then export 
> that file into Timelab, but I haven’t figured that out yet.
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> 

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

[Claudio Girardi]

FYI, some phase noise measurements on local oscillators at 106 and 117 
MHz (used for microwave transverters) can be found at http://f5lgj.chez-
alice.fr/mesure_oscillateur.html .
The PLLVCXO mentioned there, that allows locking to a 10 MHz 
reference, should be this one http://f4dru.chez-alice.fr/plvcxo/CJ2010.
pdf .

73 de Claudio, IN3OTD / DK1CG


>Messaggio originale
>Da: "Dr. David Kirkby (Kirkby Microwave Ltd)" 

>Data: 30-mag-2016 11.06 AM
>A: "Discussion of precise time and frequency measurement"
>Ogg: [time-nuts] How can I generate a very clean 1 W signal @ 116 MHz 
?
>
>I was thinking about designing a 2 m (144-146 MHz) ->HF (28-30 MHz)
>transverter, using a 116 MHz local oscillator feeding a level 30 
mixer.
>
>116 + 28 = 144
>116 + 30 = 146
>
>I'm wondering what's the best way to generate 116 MHz with very low 
phase
>noise. Phase noise at < 20 kHz offset is particularly important, but 
200
>kHz would be fairly important. Outside that, it does not matter too 
much.
>
>The ability to lock to 10 MHz would be "nice", but certainly not 
essential,
>as absolute frequency stability would not be of prime importance. 
Getting
>the phase noise as low as possible would be more important. I expect 
better
>performance can be achieved if one forgets about locking the signal 
source
>to something else, but I may be wrong.
>
>An HP 8663A sig gen has <-147 dBc/Hz at 10 kHz offset, but I'd hope 
its
>possible to produce something better than is possible in a commercial 
sig
>gen that covers up to 2.5 GHz.
>
>Dave
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>


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

[Tim Shoppa]

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

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

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

Tim N3QE

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

> I was thinking about designing a 2 m (144-146 MHz) ->HF (28-30 MHz)
> transverter, using a 116 MHz local oscillator feeding a level 30 mixer.
>
> 116 + 28 = 144
> 116 + 30 = 146
>
> I'm wondering what's the best way to generate 116 MHz with very low phase
> noise. Phase noise at < 20 kHz offset is particularly important, but 200
> kHz would be fairly important. Outside that, it does not matter too much.
>
> The ability to lock to 10 MHz would be "nice", but certainly not essential,
> as absolute frequency stability would not be of prime importance. Getting
> the phase noise as low as possible would be more important. I expect better
> performance can be achieved if one forgets about locking the signal source
> to something else, but I may be wrong.
>
> An HP 8663A sig gen has <-147 dBc/Hz at 10 kHz offset, but I'd hope its
> possible to produce something better than is possible in a commercial sig
> gen that covers up to 2.5 GHz.
>
> Dave
> ___
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> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
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>
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[time-nuts] Time dilation effects on the earth/sun cores

[Mark Sims]

Tom needs to start digging to China and run another experiment...
http://www.theregister.co.uk/2016/05/30/earths_core_is_younger_than_its_crust/  
  
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Re: [time-nuts] How can I generate a very clean 1 W signal @ 116 MHz ?

[Bernd Neubig]

Alexander Pummer wrote on  Montag, 30. Mai 2016 16:25

>KVG Neckarbischofshofen used to have a crystal in a glass envelope, which was 
>made just for that purpose it was third overtone crystal ask Bernd if that is 
>still available, of course you would need a low noise power amplifier to get 
>that 1W.
It is true that 20~30 years ago crystals in glass enclosure used to be under 
the top performant precision crystals ...until Coldweld technology was 
"re-discovered" in industry (HP did that before...).
Nowadays glass-sealing technology is no longer available (except by a few new 
manufacturers), as this is a too expensive and delicate process due to the high 
temperature of melting glass comes very close two the quartz crystal.
For a normal transverter type applications there is no need for extra low phase 
noise. As Rick has pointed out, a "regular" 116 MHz AT 5th overtone crystal in 
a resistance-weld HC-49/U (4.9 mm pin spacing) or HC-52/U or UM-1 (3.75 mm pin 
spacing) will do the job perfectly. 
There are a lot of proven circuits out there, most of them work fine with a 
crystal adjusted in series resonance. 
Certainly you can do better with more complex solutions which is like shooting 
canons to sparrows (as we say here in Germany).

BTW: Alternatively you can use a 116 MHz TCXO (as some of our customers are 
doing, getting <-155 dBc/Hz @ 10 kHz with a stability of 0.5 ppm over-10~+60°C) 
- but this is not the place for a commercial, sorry.

Have fun
Bernd
DK1AG

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

[Richard (Rick) Karlquist]

On 5/30/2016 4:06 AM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote:

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

116 + 28 = 144
116 + 30 = 146

I'm wondering what's the best way to generate 116 MHz with very low phase
noise. Phase noise at < 20 kHz offset is particularly important, but 200


The "best" way is clearly to use a 116 MHz 5th overtone crystal
oscillator, which can be locked to 10 MHz with no difficulty.
I designed hundreds of these sorts of things 40 years ago when
I worked for Zeta Labs.  You might be able to repurpose one of
those "brick" microwave sources.  They used 5th OT XO's in
that general frequency range to drive a multiplier at something
like 1 watt.  Could be perfect for you.

Rick N6RK
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Re: [time-nuts] How can I generate a very clean 1 W signal @ 116 MHz ?

[jimlux]

On 5/30/16 4:06 AM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote:

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

116 + 28 = 144
116 + 30 = 146

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

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

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



Multiply up from a clean source.
A $200 Wenzel streamline OCXO is -130 at 10 Hz, -155 at 100 Hz and -165 
from 1 kHz out.


20logN is 21 dB, so you should be able to get -140 or better at 116MHz, 
if you're careful.


A Wenzel ULN is about 10 dB quieter..
The 10 MHz ULN is about -175 dBc/Hz from 1kHz on out.

You can get a ULN for VHF (it won't be cheap) but they quote -175 dBc/Hz 
at 10kHz out for 100 MHz oscillators.


The 8663 -145 at 10 kHz spec is for the rear panel 640 MHz output, I 
believe.
On the front panel, from 0.01 to 119.9, with the H40 option, the spec is 
-132 dBc, (-142 from 120-160 MHz)


Of course, you'd have to find a working 8663A (and keep it working).
The E8663B isn't as quiet (and is also obsolete).
The E8663D at 100 MHz is -150 dBc/Hz at 10 kHz out.



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

[RICARDO EA1RJ]

Hello Dave

I use a PLLs from DF9NP Dieter and i think that it could be good for you, and 
it has Ext Ref input for GPSDO :)

You can found info here:

http://www.df9np.de/page1.html

Hope it help you

EA1RJ - Ricardo




De: time-nuts  en nombre de Dr. David Kirkby 
(Kirkby Microwave Ltd) 
Enviado: lunes, 30 de mayo de 2016 13:06
Para: Discussion of precise time and frequency measurement
Asunto: [time-nuts] How can I generate a very clean 1 W signal @ 116 MHz ?

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

116 + 28 = 144
116 + 30 = 146

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

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

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

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

[David J Taylor]

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

116 + 28 = 144
116 + 30 = 146

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

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

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

Dave
___


Dave,

This box will produce 116 MHz (tested) quite cleanly (from the data on the 
Web page):


 http://www.leobodnar.com/shop/index.php?main_page=product_info_id=234

GPS locked.

73,
David GM8ARV
--
SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu
Email: david-tay...@blueyonder.co.uk
Twitter: @gm8arv 


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

[Alexander Pummer]

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


73
KJ6UHN
Alex



On 5/30/2016 4:06 AM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote:

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

116 + 28 = 144
116 + 30 = 146

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

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

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

Dave
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-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2016.0.7598 / Virus Database: 4591/12324 - Release Date: 05/29/16


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

[Bob Camp]

Hi

There are a lot of published circuits for low noise VHF crystal oscillators.  
At the offsets you are talking about the
phase noise is mostly a function of simple signal to noise. More power in the 
crystal == lower noise. You should 
be able to do better than -165 dbc/Hz with a little fiddling. Having a EFC that 
is wide enough to lock to 10 MHz
should not degrade the noise to badly. 

Since the crystal is not a big deal at wide offsets, a “buy some and see” 
approach is by far the lowest cost way 
to get the parts to use in the circuit.  Also since vendors change process from 
month to month, what you buy today 
may not be what you get a few months from now. Not a big deal for a one off. 
Likely a PIA for a production build. 

Bob



> On May 30, 2016, at 7:06 AM, Dr. David Kirkby (Kirkby Microwave Ltd) 
>  wrote:
> 
> I was thinking about designing a 2 m (144-146 MHz) ->HF (28-30 MHz)
> transverter, using a 116 MHz local oscillator feeding a level 30 mixer.
> 
> 116 + 28 = 144
> 116 + 30 = 146
> 
> I'm wondering what's the best way to generate 116 MHz with very low phase
> noise. Phase noise at < 20 kHz offset is particularly important, but 200
> kHz would be fairly important. Outside that, it does not matter too much.
> 
> The ability to lock to 10 MHz would be "nice", but certainly not essential,
> as absolute frequency stability would not be of prime importance. Getting
> the phase noise as low as possible would be more important. I expect better
> performance can be achieved if one forgets about locking the signal source
> to something else, but I may be wrong.
> 
> An HP 8663A sig gen has <-147 dBc/Hz at 10 kHz offset, but I'd hope its
> possible to produce something better than is possible in a commercial sig
> gen that covers up to 2.5 GHz.
> 
> Dave
> ___
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Re: [time-nuts] How can I generate a very clean 1 W signal @ 116 MHz ?

[Vlad]

May be using DDS chips ?
Here is interesting work regarding DDS Phase Noise :

http://rubiola.org/pdf-articles/conference/2012-ifcs-DDS.pdf



On 2016-05-30 07:06, Dr. David Kirkby (Kirkby Microwave Ltd) wrote:

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

116 + 28 = 144
116 + 30 = 146

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


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

to something else, but I may be wrong.

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

gen that covers up to 2.5 GHz.

Dave
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and follow the instructions there.


--
WBW,

V.P.
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[time-nuts] How can I generate a very clean 1 W signal @ 116 MHz ?

[Dr. David Kirkby (Kirkby Microwave Ltd)]

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

116 + 28 = 144
116 + 30 = 146

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

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

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

Dave
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Re: [time-nuts] Timelab and the 53220A - getting best results

[Anders Wallin]

A time-interval measurement between 1-PPS outputs of your two clocks is the
most straightforward to interpret.
With the 20ps 53230A I get a noise-floor of about 1.8e-11/tau(s) for this
measurement.
I haven't tried the 100ps version, I suspect the hardware is identical and
HPAK just de-rates the spec/firmware to 100ps in order to 'segment the
market'.

In frequency counting mode things are tricky because it does some sort of
omega-counting in default (CONT) mode.
This makes the effective bandwidth depend on the gate-time. (see 2nd image
of 2nd link).
The pi-counting mode is called RCON and is undocumented AFAIK. I got
3e-11/tau(s) with a 1s gate time and here I would expect noise-floor
measurements to fall on this same line independent of gate time (I haven't
verified this).

http://www.anderswallin.net/2015/06/cont-vs-rcon-mode-on-the-53230a-frequency-counter/
http://www.anderswallin.net/2015/04/keysight-53230a-noise-floor-test/

Anders


On Sat, May 28, 2016 at 7:11 PM, Nick Sayer via time-nuts <
time-nuts@febo.com> wrote:

> So far, I’ve been configuring my 53220A for frequency measurements with a
> 500 msec gate time, and using the external reference and one input.
>
> If instead I send the two devices into inputs A and B, and ask for the
> time interval between the two and give that to Timelab, my results look
> quite a bit worse.
>
> At the moment, I’m doing that with a pair of 5680As. The ADEV at 100s is
> reasonably close to the spec at 1.83E-12, but the tau at 10s is what it’s
> *supposed* to be at 1s: 1.43E-11. At 1s, it’s 1.42E-10. The line is quite
> linear between those points, but the slope is way off the spec. The
> frequency difference graph supports this view - it shows a ±2E-10 “haze.”
>
> I don’t have any reason to believe either oscillator is misbehaving to an
> extent that would explain this. I’m fairly sure I’m making some kind of
> fundamental newbie mistake and the test setup is introducing some sort of
> error, or I’m inside of the uncertainty of the 53220A and that’s why it’s
> showing poorly at low tau. My money is on the former. :)
>
> The behavior I see suggests that how Timelab works with the 53220A is that
> it sends a command to obtain a single measurement over and over again.
> Thus, the network latency figures into the measurement timespan, I think.
> I’m sure there’s a way to record measurements in the 53220A internally and
> then export that file into Timelab, but I haven’t figured that out yet.
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