[time-nuts] New Question on HP3048A Phase Noise Test Set

[Martyn Smith]

Hi,

I need some help on using the HP3048A Phase Noise Test Set (11848A, 3561A, 
3585A, 3325A).

My company makes a ultra low noise frequency standard with ten outputs. 
Apart from very low phase noise (-112 dBc/Hz @ 1 Hz with a -170 dBc/Hz noise 
floor) I also claim all spurious to be < -120 dBc.  This includes the line 
frequency spurious.

I'm happy my test set is making accurate phase noise results as I agree with 
other test results on sample oscillators to < 2 dB.

But I seem to have an error on measuring spurs.

As you all know, when the 3048A detects a big peak, it marks it in red and 
shows the actual value, rather than normalizing it to a 1 Hz bandwidth.

To test the 3048A accuracy I inject a spur at a known level using a 
directional coupler (similar to the single-sided spur calibration method).

I confirm the spur level on the spectrum analyzer.  However the 3048A always 
says the spur is 6 dB lower than it actually is (6 dB plus/minus 0.5 dB).

Can anyone tell me why this is so.

I wondered if it had something to do with phase noise and amplitude noise 
not being the same thing.

Any response would be appreciated.

Best Regards

Martyn

This Email is from:

Martyn Smith
Precision Test Systems LTD
Tel: +44 (0) 1245 329608
Email: martyn at ptsyst.com
Web: www.ptsyst.com

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----- Original Message ----- 
From: <time-nuts-request at febo.com>
To: <time-nuts at febo.com>
Sent: Saturday, December 08, 2007 12:15 AM
Subject: time-nuts Digest, Vol 41, Issue 20


> Send time-nuts mailing list submissions to
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> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of time-nuts digest..."
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>
> Today's Topics:
>
>   1. HP105A/B technical documentation? (Christoffer Bruman)
>   2. Wavecrest DTS-2070C in the house (Magnus Danielson)
>   3. Re: Super stable BVA Quartz resonators... BVA?? (Didier Juges)
>   4. Re: Super stable BVA Quartz resonators... BVA?? (Didier Juges)
>   5. Re: Super stable BVA Quartz resonators... BVA??
>      (Richard (Rick) Karlquist)
>   6. Re: Cesium Oscialltors and Low Phase Noise Frequency Standard
>      (Enrico Rubiola)
>   7. Re: Super stable BVA Quartz resonators... BVA?? (Magnus Danielson)
>   8. Re: Super stable BVA Quartz resonators... BVA?? (Brian Styles)
>   9. Re: Super stable BVA Quartz resonators... BVA?? (Enrico Rubiola)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Fri, 07 Dec 2007 20:12:49 +0100
> From: Christoffer Bruman <bruman at telia.com>
> Subject: [time-nuts] HP105A/B technical documentation?
> To: time-nuts at febo.com
> Message-ID: <47599B31.7020703 at telia.com>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Dear List,
>
> I am searching for a service manual (or at least a complete schematic)
> of HP:s 105A (or B) frequency standard, preferably the later version
> with the 10811x inside. There seems to be plenty of information
> downloadable on the 10811x itself, but I am interested in the details on
> how HP solved things like power supply, grounding, internal EFC,
> external DC inlet, etc in these units.
>
> If anyone has any useful links to the manual or a schematic, or
> shareable files, I would be very thankful.
>
> Best regards,
>
> Christoffer :)
>
>
>
> ------------------------------
>
> Message: 2
> Date: Fri, 07 Dec 2007 21:43:36 +0100 (CET)
> From: Magnus Danielson <magnus at rubidium.dyndns.org>
> Subject: [time-nuts] Wavecrest DTS-2070C in the house
> To: time-nuts at febo.com
> Message-ID: <20071207.214336.-601741223.cfmd at bredband.net>
> Content-Type: Text/Plain; charset=us-ascii
>
> Hi fellow time-nuts!
>
> I am just happy to let you know that I am now proud owner of a Wavecrest
> DTS-2070C. I also have a SIA-3000P from before, which is nice for jitter 
> but
> not as versatile as you would wish at all times. I think the DTS will be a 
> nice
> complement.
>
> I was not suspect it to be that large thought, but ah well, life is full 
> of
> supprises.
>
> It fired up and I have it doing some counting going down, but I think it 
> is
> time to read the manual to figure some things out. Otherwise it seems 
> fairly
> easy to operate.
>
> The LCD is BIG, so there is no chance missing the numbers even from some
> distance.
>
> Hmm. Time to make some shootout here... :)
>
> Cheers,
> Magnus
>
>
>
> ------------------------------
>
> Message: 3
> Date: Fri, 7 Dec 2007 17:08:39 -0600
> From: "Didier Juges" <didier at cox.net>
> Subject: Re: [time-nuts] Super stable BVA Quartz resonators... BVA??
> To: "'Discussion of precise time and frequency measurement'"
> <time-nuts at febo.com>
> Message-ID: <06db01c83926$1b2a0be0$6501a8c0 at didierhp>
> Content-Type: text/plain; charset="iso-8859-1"
>
> That would be pretty close, for once (referring to google translations :-)
>
> Here is the translation from Oscilloquartz themselves:
>
> "French expression meaning "Enclosure with Improved Ageing". The OSA BVA
> crystal oscillators employ special techniques to achieve stability
> performance, unmatched by any other crystal device, i.e. typically 1 x
> 10-11/day."
>
> Didier KO4BB
>
>> -----Original Message-----
>> From: time-nuts-bounces at febo.com
>> [mailto:time-nuts-bounces at febo.com] On Behalf Of Chuck Harris
>> Sent: Friday, December 07, 2007 10:37 AM
>> To: Discussion of precise time and frequency measurement
>> Subject: Re: [time-nuts] Super stable BVA Quartz resonators... BVA??
>>
>> A googlized translation is:
>>
>> Improved Housing for Aging
>>
>> -Chuck Harris
>>
>> John Franke wrote:
>> > Try:
>> >
>> > Bo?tier ? Vieillissement Am?lior?
>> >
>> > John WA4WDL
>> >
>
>
>
>
> ------------------------------
>
> Message: 4
> Date: Fri, 7 Dec 2007 17:17:59 -0600
> From: "Didier Juges" <didier at cox.net>
> Subject: Re: [time-nuts] Super stable BVA Quartz resonators... BVA??
> To: "'Discussion of precise time and frequency measurement'"
> <time-nuts at febo.com>
> Message-ID: <06dc01c83927$68d90520$6501a8c0 at didierhp>
> Content-Type: text/plain; charset="us-ascii"
>
> I am not aware of other crystal oscillators with better performance, so
> either I am missing something (the more likely explanation) or there is
> something to it.
>
> Maybe the cut is simply a smoke screen and the outstanding performance is
> actually due to other process detail(s) not disclosed?
>
> Or maybe their oscillators are not that good, they just blow smoke really
> well.
>
> Didier KO4BB
>
>> -----Original Message-----
>> From: time-nuts-bounces at febo.com
>> [mailto:time-nuts-bounces at febo.com] On Behalf Of Richard
>> (Rick) Karlquist
>> Sent: Friday, December 07, 2007 10:45 AM
>> To: Discussion of precise time and frequency measurement
>> Subject: Re: [time-nuts] Super stable BVA Quartz resonators... BVA??
>>
>> Reminds me of the "SC" cut crystal.
>> It either means "Stress Compensated" or "Santa Clara", where
>> it was discovered :-)
>>
>> The BVA has been around for a long time and you would think
>> that if there was really something to it, everybody would be
>> making them.  Of course, they are very difficult to make.
>>
>> Rick Karlquist N6RK
>
>
>
>
> ------------------------------
>
> Message: 5
> Date: Fri, 07 Dec 2007 15:52:15 -0800
> From: "Richard (Rick) Karlquist" <richard at karlquist.com>
> Subject: Re: [time-nuts] Super stable BVA Quartz resonators... BVA??
> To: Discussion of precise time and frequency measurement
> <time-nuts at febo.com>
> Message-ID: <4759DCAF.1030404 at karlquist.com>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Having low aging is nice, but the real problem is
> frequency jumps.  Do we know that they are the best
> in that respect?  If a crystal can jump 1E-10, then
> that represents 10 days of aging all at once.
>
> Rick Karlquist, N6RK
>
> Didier Juges wrote:
>> I am not aware of other crystal oscillators with better performance, so
>> either I am missing something (the more likely explanation) or there is
>> something to it.
>>
>> Maybe the cut is simply a smoke screen and the outstanding performance is
>> actually due to other process detail(s) not disclosed?
>>
>> Or maybe their oscillators are not that good, they just blow smoke really
>> well.
>>
>> Didier KO4BB
>>
>>> -----Original Message-----
>>> From: time-nuts-bounces at febo.com
>>> [mailto:time-nuts-bounces at febo.com] On Behalf Of Richard
>>> (Rick) Karlquist
>>> Sent: Friday, December 07, 2007 10:45 AM
>>> To: Discussion of precise time and frequency measurement
>>> Subject: Re: [time-nuts] Super stable BVA Quartz resonators... BVA??
>>>
>>> Reminds me of the "SC" cut crystal.
>>> It either means "Stress Compensated" or "Santa Clara", where
>>> it was discovered :-)
>>>
>>> The BVA has been around for a long time and you would think
>>> that if there was really something to it, everybody would be
>>> making them.  Of course, they are very difficult to make.
>>>
>>> Rick Karlquist N6RK
>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to 
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>>
>
>
>
> ------------------------------
>
> Message: 6
> Date: Sat, 8 Dec 2007 01:07:00 +0100
> From: Enrico Rubiola <rubiola at femto-st.fr>
> Subject: Re: [time-nuts] Cesium Oscialltors and Low Phase Noise
> Frequency Standard
> To: Discussion of precise time and frequency measurement
> <time-nuts at febo.com>
> Message-ID: <763FA38A-AFBE-41D9-89BF-D9F798827B71 at femto-st.fr>
> Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed
>
> Martyn,
> designing a Cs standard is not the job for a single man,
> yet I might help you to find frustrated scientists who worked
> on a Cs project (some 10 years ago I took a part in a project,
> designing damn impossible precision electronics).
>
> About the noise of your quartz oscillator, not bad.
> Yet:
>
> Oscilloquartz 8607 has -128.5 dBrad^2/Hz at 1 Hz offset, at 5 MHz,
> which scales to -122.5 at 10 MHz, thus -125.5 dBc.
> Off the shelf, may have some delay.
>
> Rakon has -132 dBrad^2/Hz at 1 Hz offset, at 5 MHz,
> which scales to -126 at 10 MHz, thus -129 dBc.
> Small production for space, not sure you can actually
> buy it.
>
> In your oscillator, is the power dissipated by the quartz of
> 40 microwatts?
>
> Can you send a spectrum?
>
> I am getting great fun in reverse engineering the oscillator
> noise.  The noise I mean, not the oscillator.  This takes
> some 40-50 pages of my forthcoming book on
> phase noise and frequency stability in oscillators.
> You can't enter an order number, you must wait for
> Cambridge University Press, which is a non-profit
> company.
>
> Cheers,
> Enrico
>
>
> On 6 Dec 2007, at 15:12 , Martyn Smith wrote:
>
>> Hi,
>>
>> Is there anyone out there clever enough to design me a cesium
>> frequency standard??
>>
>> There's only two manufacturers that I know of and there's room for
>> another supplier.
>>
>> Also you may be interested to read we have just developed what we
>> believe to be the worlds lowest close-in phase noise 10 MHz
>> oscillator.
>>
>> It makes -121 dBc/Hz @ 1 Hz.  Noise floor is only -162 dBc/Hz at
>> the moment, but we are working on reducing this a further 5 to 10 dB.
>>
>> Enter your order number here......
>>
>> Best Regards
>>
>> Martyn
>>
>> This Email is from:
>>
>> Martyn Smith
>> Precision Test Systems LTD
>> Tel: +44 (0) 1245 329608
>> Email: martyn at ptsyst.com
>> Web: www.ptsyst.com
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/
>> time-nuts
>> and follow the instructions there.
>
> Enrico Rubiola
> professor of electronics
>
> web: http://rubiola.org
> e-mail: rubiola at femto-st.fr
>
> FEMTO-ST Institute
> 32 av. de l'Observatoire
> 25044 Besancon, FRANCE
> voice: +33(0)381.853940 (E.Rubiola)
> voice: +33(0)381.853999 (switchboard)
> fax: +33(0)381.853998
>
>
>
>
> ------------------------------
>
> Message: 7
> Date: Sat, 08 Dec 2007 01:10:09 +0100 (CET)
> From: Magnus Danielson <magnus at rubidium.dyndns.org>
> Subject: Re: [time-nuts] Super stable BVA Quartz resonators... BVA??
> To: time-nuts at febo.com, didier at cox.net
> Message-ID: <20071208.011009.-1748779747.cfmd at bredband.net>
> Content-Type: Text/Plain; charset=us-ascii
>
> From: "Didier Juges" <didier at cox.net>
> Subject: Re: [time-nuts] Super stable BVA Quartz resonators... BVA??
> Date: Fri, 7 Dec 2007 17:17:59 -0600
> Message-ID: <06dc01c83927$68d90520$6501a8c0 at didierhp>
>
>> I am not aware of other crystal oscillators with better performance, so
>> either I am missing something (the more likely explanation) or there is
>> something to it.
>>
>> Maybe the cut is simply a smoke screen and the outstanding performance is
>> actually due to other process detail(s) not disclosed?
>
> Let's recall that the BVA isn't the same as a cut, but rather an approach 
> to
> handle and mount the cut crystal. The BVA exists in both AT and SC cuts.
>
> The analysis of Rick et.al. for the E1938 was pointing in another 
> improvement.
>
> Also, there are many ways to cut a crystal. :)
>
> Smokescreen or not, Oscilloquartz clearly beleive in the BVA methodology 
> and
> they seems to have customers for them too.
>
> Is the E1938 commercially available? If not, is there a followup?
>
> Do we really need BVAs or similars for most new designs, considering the 
> price,
> size and availability of modern telecom rubidiums?
>
>> Or maybe their oscillators are not that good, they just blow smoke really
>> well.
>
> Well, that would be stupid, since it is easy enought to measure and 
> verify.
>
> Cheers,
> Magnus
>
>
>
> ------------------------------
>
> Message: 8
> Date: Sat, 08 Dec 2007 00:15:11 +0000
> From: Brian Styles <brian.styles at cdmnet.org>
> Subject: Re: [time-nuts] Super stable BVA Quartz resonators... BVA??
> To: Discussion of precise time and frequency measurement
> <time-nuts at febo.com>
> Message-ID: <4759E20F.8090408 at cdmnet.org>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Didier Juges wrote:
>
> > Maybe the cut is simply a smoke screen and the outstanding performance
> > is actually due to other process detail(s) not disclosed?
>
> There's quite a bit of guff on the "Oscilloquartz" website - especially
> if you find your way to the OXCO 8607-B datasheet (pdf).
>
> I'm not qualified to weigh this all up, but they point out a double oven
> and an "electrodeless, SC-cut, 3rd overtone crystal, decoupled from its
> mounting structure by four rigid bridges". And they go on to list the
> consquent benefits.
>
> They've made over 10,000 of them. Anyone know what they're charging...?
>
> Yours,
>
>
>
> -Brian Styles
>
>
>
>
> ------------------------------
>
> Message: 9
> Date: Sat, 8 Dec 2007 01:15:00 +0100
> From: Enrico Rubiola <rubiola at femto-st.fr>
> Subject: Re: [time-nuts] Super stable BVA Quartz resonators... BVA??
> To: Discussion of precise time and frequency measurement
> <time-nuts at febo.com>
> Message-ID: <1DC37668-4B01-4B64-9092-845440283C49 at femto-st.fr>
> Content-Type: text/plain; charset=ISO-8859-1; delsp=yes; format=flowed
>
> BVA is a French acronym, it means
> Besson Vieillissement Amelior?
> Reymond Besson is the scientist who invented it, here in Besancon,
> a friend of mine, officially retired, yet still at work.
> "Vieillissement" means aging,
> "Amelior?" means improved.
>
> Somebody says that it also means "Besson vieux ?ne", if you
> know French, and French culture because this is not the kind
> of thing you can translate without killing the meaning.
>
>
>
> On 7 Dec 2007, at 17:15 , Michael Baker wrote:
>
>> Hello, All--
>>
>> In doing some reading to educate myself on the relative
>> short and long-term stability characteristics of the best
>> grade quartz resonators, I find that BVA cut resonators
>> are on the leading edge of quartz crystal technology.
>>
>> I have found out how a BVA resonator is fabricated, but
>> I have not discovered what the acronym "BVA" stands for.
>>
>> I suspect that the "B" in "BVA" may refer to Raymond Besson
>> the discoverer of the BVA quartz resonator, but I
>> have not been able to confirm that.
>>
>> Can anyone on the list shed some light on this?
>>
>> Mike Baker
>> ----------------------
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/
>> time-nuts
>> and follow the instructions there.
>
> Enrico Rubiola
> professor of electronics
>
> web: http://rubiola.org
> e-mail: rubiola at femto-st.fr
>
> FEMTO-ST Institute
> 32 av. de l'Observatoire
> 25044 Besancon, FRANCE
> voice: +33(0)381.853940 (E.Rubiola)
> voice: +33(0)381.853999 (switchboard)
> fax: +33(0)381.853998
>
>
>
>
> ------------------------------
>
> _______________________________________________
> time-nuts mailing list
> time-nuts at febo.com
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>
> End of time-nuts Digest, Vol 41, Issue 20
> *****************************************
>