[time-nuts] GPSDO 10 MHz Distribution Amp

Chuck Smallhouse w7cs at theriver.com
Sun Jun 21 19:53:44 EDT 2009


At 04:39 PM 6/21/2009, time-nuts-request at febo.com wrote:
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>DEMI (Down East Microwave) has 10 MHz distibution amplifers for 
>sale, either in kit form or built and tested.  The kits ( all the 
>parts, but sans connectors and enclosure) are only $25 and delivery was quick.

Each output is driven by an ERA device and has a two stage low pass 
filter.  I just put one together and it took about an hour.  Damn 
some of SMD chip capacitors are really small !  But I'm proud that at 
my age (77) I can still solder with a steady hand.

Chuck, W7CS











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>Today's Topics:
>
>    1. Re: LF power supply  noise (Mike Monett)
>    2. Re: Thunderbolts for sale (Richard W. Solomon)
>    3. Re: Bad capacitors (was Volt-nuts cooperation?) (Dave Mallery)
>    4. Re: GPSDO 10 MHz Distribution Amp (Don Key)
>    5. Re: GPSDO 10 MHz Distribution Amp (dave powis)
>
>
>----------------------------------------------------------------------
>
>Message: 1
>Date: Sun, 21 Jun 2009 15:27:54 -0300
>From: "Mike Monett" <xde-l2g3 at myamail.com>
>Subject: Re: [time-nuts] LF power supply  noise
>To: "" <time-nuts at febo.com>
>Message-ID: <mailman.2041.1245627544.2451.time-nuts at febo.com>
>Content-Type: text/plain; charset="iso-8859-1"
>
>
>   > Mike,
>
>   [...]
>
>   >> One of  the reasons I was attracted to the 543310A  was  it could
>   >> display 14  digits of frequency in one second. Sine then,  I have
>   >> figured a way to resolve 16 digits in one second, so that part of
>   >> the spec is no longer interesting.
>
>   > As was  described  by J. J. Snyder  in  "An  Ultra-High Resolution
>   > Frequency Meter"  in the FCS 1981 (as available from IEEE  UFFC) I
>   > assume, basically using the fact that adding more  measurements in
>   > a dense time raises the degrees of freedom and allows  for quicker
>   > interpolation.
>
>   > Modern counters like HP 53131, HP 53132 as well as Pendulum CNT-90
>   > or Fluke 6690 uses similar approaches.
>
>   I can't  find  any copies that are not payware, but  it  is unlikely
>   there is any connection between the methods.
>
>   Conventional averaging  methods are limited by the  exponential rise
>   in number  of  samples  that are required to  improve  the  SNR. The
>   measurement ends  up  taking too long, or  the  system  drifts which
>   renders the mesurement useless.
>
>   This provides  an  effective barrier to  the  amount  of improvement
>   possible in  SNR, and the available precision that is  possible with
>   conventional technology.
>
>   Binary Sampling  works  a completely different way.  It  ignores the
>   amplitude of  the  sample,  and only records  the  direction  of the
>   error.
>
>   According to  the Central Limit Theorem, the mean of  Gaussian noise
>   is zero.  This  forces the Binary Sampler to  converge  on  the true
>   value of the signal, and ignore the error caused by the amplitude of
>   the sample.
>
>   This is  a  really  big thing. The  problem  of  using  averaging to
>   improve sigma  has existed for over 109 years. And  nobody  has been
>   able to solve it up till now.
>
>   With a heterodyne sampling system, or conventional mixer technology,
>   the sample  delta is the offset frequency divided by  the  square of
>   the reference frequency:
>
>   Delta = Offset / Ref * Ref
>
>   With a delta of 1Hz and reference of 1 MHz, the sample delta is
>
>   1 / (1e6)^2 = 1 / 1e12,
>
>   or 1 picosecond.
>
>   Since the Binary Sampler discards noise, the result is  1 picosecond
>   resolution in 1 second.
>
>   I show  this  on my web site. The schematic for  the  measurement is
>   shown in Fig. 1 at
>
>   http://pstca.com/sampler/design.htm
>
>   A simple  boxcar  smoother  is used to  integrate  the  samples. The
>   result with different smoothing values is shown at
>
>   http://pstca.com/sampler/smooth.htm
>
>   A system  with  18.38  ps rms  jitter  would  require  averaging 338
>   waveforms to  obtain  1ps  rms  jitter.  With  conventional sampling
>   technology, this  would  require 169 seconds, and  the  system would
>   probably drift  during  the measurement,  rendering  the measurement
>   invalid.
>
>   So it  is not possible to obtain this amount of improvement  in this
>   system, and the measurement is impossible.
>
>   The Binary  Sampler gives 1ps resolution in 1 second. This  is shown
>   in Fig. 4 at
>
>   http://pstca.com/sampler/binsamp.htm
>
>   No other  system  can  achieve  this  performance.  And  anyone with
>   sufficient skill can duplicate this result at home.
>
>   Extending this to higher frequency, it should be possible  to obtain
>   a 1Hz offset at 100MHz with 1 uHz resolution. This gives
>
>   1 / (1e8)^2 = 1e-16 resolution in 1 second.
>
>   I do not think any existing equipment from HP, Fluke, or Pendulum or
>   anyone else can come close to matching this level of performance.
>
>   Also, existing  technology  must deal with noise  and  the averaging
>   problem. This  eliminates  much of the  performance  boundaries from
>   consideration.
>
>   As a  result,  conventional  technology cannot  reach  1e-16  in one
>   second.
>
>   > As being  reported, such mechanisms does not fair  well  with ADEV
>   > calculations, and especially the overlapping variants of  ADEV and
>   > den MDEV  and TDEV which was inspired by that  particular article,
>   > so using it twice forms unwanted filters.
>
>   My approach delivers continuous samples. No missing or extra bits.
>
>   >> The 543310A  can  do   a   single-shot  time  measurement  with a
>   >> resolution of  200ps,  and gets down to 1ps  with  averaging. The
>   >> HP5370B does  20ps  single-shot,   and  will  resolve  100fs with
>   >> averaging. But  I have figured a way to measure  2ps single-shot,
>   >> and a bit better with averaging. So that part of the spec  is not
>   >> so interesting any more.
>
>   > I assume  you  really mean HP 53310A and not HP  543310A,  even if
>   > your typing is consistent. The listed numbers is when weigthing in
>   > how various  jitter sources combine upon averaging  and  should be
>   > considered a bit conservative.
>
>   > By all  means  describe   what   you   mean  by  2  ps single-shot
>   > resolution.
>
>   That will  cure me of trying to type complex numbers  when  copy and
>   paste works  so  much better. But now I have to try  and  figure out
>   what your "weigthing" really means:)
>
>   The 2ps  single  shot  is  dead  straight  conventional time-to-time
>   conversion. Nothing new there, except I think I have some new tricks
>   on stabilizing  the  circuits against drift,  and  providing  a much
>   faster response  to  the  zero-crossing at  the  end  of  the timing
>   interval. All these reduce the noise in the sampling process.
>
>   But the real trick is applying the Binary Sampling technique  to the
>   result. That allows a huge reduction in the noise from  the sampling
>   process, and converges rapidly on a much more precise solution.
>
>   >> The 543310A will display the phase and frequency changes in a PLL
>   >> step response.  But  you can get the frequency  response  just by
>   >> looking at  the  VCO  DC error voltage. And if  you  look  at the
>   >> voltage across the bottom capacitor in a type 3 loop, you get the
>   >> phase response. Here's a picture:
>
>   >>         |
>   >>        --- C1
>   >>        ---
>   >>         |
>   >>         |----------O < -  Phase Error
>   >>         |       |
>   >>        --- C2   \
>   >>        ---      / R1
>   >>         |       \
>   >>         |       |
>   >>        ---     ---
>   >>         -       -
>
>   > You should recall that when HP built their line of analyzers, they
>   > where thinking  "what can we make this cool ZDT  core  do?" rather
>   > than attempting to build the best analyzer for all responsens.
>
>   I have a slightly different impression. I sold a lot of equipment to
>   Boisie, Idaho,  and I used to make a lot of trips there in  my Piper
>   Malibu, which was about the only realistic way of getting there from
>   San Jose:
>
>   http://www.jetphotos.net/viewphoto.php?id=5874208&nseq=0
>
>   There was  a  lot  of political  infighting  at  Boisie  involved in
>   development of  new equipment. The winner pretty  much  had whatever
>   say he wanted in the direction, and he ignored the input  from other
>   competent engineers.
>
>   As a  result, the equipment was limited by  that  individual's scope
>   and abilities. The result is much of HP's equipment suffered.
>
>   One example  is the 20ps single-shot resolution of the HP  5370B has
>   never been  matched by any later equipment, as far as I know.  A few
>   engineers at Boisie complained bitterly about the loss.
>
>   >> So about  the  only thing left of interest is  histograms  of the
>   >> jitter. Unfortunately, the 543310A cannot store enough samples to
>   >> really make an interesting graph. What I would like to be able to
>   >> do is  similar to an invention I made for the disk  industry long
>   >> ago, called  Phase Margin Analysis. There is a  brief description
>   >> on my web page at
>
>   >>   http://pstca.com/patents.htm#phasemargin
>
>   > Somewhere in  my map of apps there is a HP appnote  for  doing the
>   > same, to discs, intended for disc industry, back in the days.
>
>   That may  very well be a result of my invention,  which  occurred in
>   1970, was published in 1979, and was copied by IBM in the 1990's.
>
>   But I have all the HP appnotes for disk. I don't recall any  of them
>   describing what I show above. Can you provide more information?
>
>   [...]
>
>   > The 53310A  was  a  nice convenient tool  at  its  time,  but it's
>   > performance isn't  up to spec with modern times. It seems  like HP
>   > didn't pursue  it   into   much   deeper   levels   after  its VXI
>   > instruments, where as others went deeper.
>
>   I'm not  sure  about this, but I don't think there is  any  later HP
>   equipment that can approach what the 53310A does.
>
>   But I  can  now  match or beat it by orders  of  magnitude.  This is
>   sufficient for  our current needs, but I will always  be  working on
>   newer technology to break through the limits we now have.
>
>   > Cheers,
>   > Magnus
>
>   Thanks,
>
>   Mike
>
>
>
>------------------------------
>
>Message: 2
>Date: Sun, 21 Jun 2009 14:24:25 -0700 (GMT-07:00)
>From: "Richard W. Solomon" <w1ksz at earthlink.net>
>Subject: Re: [time-nuts] Thunderbolts for sale
>To: Discussion of precise time and frequency measurement
>         <time-nuts at febo.com>
>Message-ID:
> 
><10269879.1245619465545.JavaMail.root at mswamui-blood.atl.sa.earthlink.net>
>
>Content-Type: text/plain; charset=UTF-8
>
>Did you receive my e-mail ?
>
>73, Dick, W1KSZ
>
>-----Original Message-----
> >From: Brian Kirby <kilodelta4foxmike at gmail.com>
> >Sent: Jun 19, 2009 9:49 PM
> >To: Discussion of precise time and frequency measurement 
> <time-nuts at febo.com>
> >Subject: [time-nuts] Thunderbolts for sale
> >
> >I will have two Trimble Thunderbolts GPSDO, that I will be selling.
> >
> >Both were bought thru the Time-Nuts purchases.  There is nothing wrong
> >with these units, they are operational, and surplus to my needs.
> >
> >One unit comes with the Ault power supply and power connector.
> >
> >The second unit comes without a power supply and I will be furnishing a
> >pig-tailed power lead connector.
> >
> >I do not have pay-pal (sorry, I gave up on *bay...) and I can send COD.
> >I can only make this offer for the lower 48 of the United States.
> >
> >If you are interested, please contact me off this list.
> >
> >Brian Kirby - KD4FM
> >
> >
> >
> >
> >
> >_______________________________________________
> >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: 3
>Date: Sun, 21 Jun 2009 16:12:35 -0600
>From: Dave Mallery <dave.mallery at gmail.com>
>Subject: Re: [time-nuts] Bad capacitors (was Volt-nuts cooperation?)
>To: Discussion of precise time and frequency measurement
>         <time-nuts at febo.com>
>Message-ID:
>         <3010c9470906211512r73738824xf7c33fb2fc3f7757 at mail.gmail.com>
>Content-Type: text/plain; charset=windows-1252
>
>hi
>
>many thanks for the heads-up on the pg505 caps!
>
>they are supposed to be 350 ufd at 75 vdc.  they are anything but.
>
>(goes back to mixing/matching caps...)
>
>dave
>
>On Sun, Jun 21, 2009 at 10:21 AM, Mark Sims <holrum at hotmail.com> wrote:
>
> >
> > The problems I saw were mostly hard failures in the caps
> > (opens/shorts/etc).  These were in both power caps and signal caps.
> >
> > One lot that I saw was a group of 12 Mettler scales.  6 were used daily and
> > 6 were never used backup units.  When the company shut down the operations
> > that used the scales,  they were sold.  All the used units worked 
> fine.  The
> > backup units all had capacitor problems.
> >
> > I also bought a lot of new-in-box Tektronix TM500 modules.  Most wound up
> > having flakey capacitors.  BTW,  EVERY (new or used)  Tek  PG505 pulse
> > generator you will come across will have bad power supply filter caps...
> >  unless they were replaced.
> >
> >
> > ----------------------------------------
> >
> >
> > Does this happen even if the electrolytics are reformed before use?
> > _________________________________________________________________
> > Lauren found her dream laptop. Find the PC that?s right for you.
> > http://www.microsoft.com/windows/choosepc/?ocid=ftp_val_wl_290
> > _______________________________________________
> > 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.
> >
>
>
>
>--
>Dave Mallery, K5EN                 (ubuntu linux 9.04)
>HC31 Box 99E;                   Williamsburg,  NM  87942
>
>no gates...
>  no windows!
>    free at last!
>  linux counter #64628 (since 1997)
>
>"People aren't as dumb as Microsoft needs them to be."
>--PJ, May 2007
>
>
>------------------------------
>
>Message: 4
>Date: Mon, 22 Jun 2009 00:14:23 +0100
>From: "Don Key" <don.key at ntlworld.com>
>Subject: Re: [time-nuts] GPSDO 10 MHz Distribution Amp
>To: "Discussion of precise time and frequency measurement"
>         <time-nuts at febo.com>
>Message-ID: <04B4AD11A8FC49DAA586C95521161AEE at JimPC>
>Content-Type: text/plain; format=flowed; charset="UTF-8";
>         reply-type=original
>
>Hi Dave
>
>Do you supply your DA1-4L distribution amp as a ready-built unit?
>Your PDF Technical manual says you do, but there are only prices for the
>kits on your ordering page.
>Cheers.
>
>Jim.
>----- Original Message -----
>From: "dave powis" <g4hup at btinternet.com>
>To: "Discussion of precise time and frequency measurement"
><time-nuts at febo.com>
>Sent: Sunday, June 21, 2009 5:34 PM
>Subject: Re: [time-nuts] GPSDO 10 MHz Distribution Amp
>
>
>Hi Paul,
>
>Sounds a reasonable approach to me where an equal 2 way split is needed, and
>you already have adequate signal level available.  May not be up to
>'time-nuts' precision etc, but it is a practical method that will give what
>you need.  If you ever need to remove one Rig, just remember to terminate
>the unused split output in 50R!
>
>However, when you get yourself an analyser, sig gen or counter that takes
>the 10MHz reference, then you will need a DA!  Comeback to me
>(http://g4hup.com) or TAPR then!
>
>73,
>Dave
>
>http://g4hup.com
>
>
>
>
>________________________________
>From: Paul Christensen <w9ac at arrl.net>
>To: Discussion of precise time and frequency measurement
><time-nuts at febo.com>
>Sent: Sunday, 21 June, 2009 5:18:51 PM
>Subject: [time-nuts] GPSDO 10 MHz Distribution Amp
>
>In the next couple weeks, I plan on distributing the output of my GPSDO to a
>pair of Icom transceivers.  I've thought about using a DA like the TAPR
>TADD-1, but it seems that I can simply split the output of the +13 dBm GPSDO
>with a Z=50, 3dB equal power divider, that will yield an output of ~ +9.5
>dBm to each transceiver.
>
>I can't foresee any port isolation issues that would make necessitate the
>use of the DA for this application and the 3 dB "hit" in level to each
>transceiver still seems reasonable for proper transceiver operation.  Am I
>not considering something important?  Also, I do not want to add any noise
>with such a distribution that would in any way destroy the excellent phase
>noise characteristics of my GPSDO.  Thoughts?
>
>Paul, W9AC
>
>_______________________________________________
>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: 5
>Date: Sun, 21 Jun 2009 16:38:58 -0700 (PDT)
>From: dave powis <g4hup at btinternet.com>
>Subject: Re: [time-nuts] GPSDO 10 MHz Distribution Amp
>To: Discussion of precise time and frequency measurement
>         <time-nuts at febo.com>
>Message-ID: <720079.15159.qm at web86306.mail.ird.yahoo.com>
>Content-Type: text/plain; charset=utf-8
>
>Hi Jim,
>
>Thanks for the enquiry.  I do prefer to supply kits, as I am not a 
>full time business, and need to work for a living!  However, on 
>request I do build units, so if that is what you want, I can quote for that.
>
>Cost for the DA1-4L assembled will depend on the connectors you want 
>fitted - if you note from the page, I don't supply connectors with 
>the kit, since some folks want BNC's to fit in their systems, while 
>others want SMA's.   Let me know what connector you are interested 
>in, and where the finished unit is to be shipped to, and I'll put a 
>quote together.
>
>Best 73,
>Dave, G4HUP
>
>
>
>
>________________________________
>From: Don Key <don.key at ntlworld.com>
>To: Discussion of precise time and frequency measurement <time-nuts at febo.com>
>Sent: Monday, 22 June, 2009 12:14:23 AM
>Subject: Re: [time-nuts] GPSDO 10 MHz Distribution Amp
>
>Hi Dave
>
>Do you supply your DA1-4L distribution amp as a ready-built unit?
>Your PDF Technical manual says you do, but there are only prices for 
>the kits on your ordering page.
>Cheers.
>
>Jim.
>----- Original Message ----- From: "dave powis" <g4hup at btinternet.com>
>To: "Discussion of precise time and frequency measurement" 
><time-nuts at febo.com>
>Sent: Sunday, June 21, 2009 5:34 PM
>Subject: Re: [time-nuts] GPSDO 10 MHz Distribution Amp
>
>
>Hi Paul,
>
>Sounds a reasonable approach to me where an equal 2 way split is 
>needed, and you already have adequate signal level available.  May 
>not be up to 'time-nuts' precision etc, but it is a practical method 
>that will give what you need.  If you ever need to remove one Rig, 
>just remember to terminate the unused split output in 50R!
>
>However, when you get yourself an analyser, sig gen or counter that 
>takes the 10MHz reference, then you will need a DA!  Comeback to me 
>(http://g4hup.com) or TAPR then!
>
>73,
>Dave
>
>http://g4hup.com
>
>
>
>
>________________________________
>From: Paul Christensen <w9ac at arrl.net>
>To: Discussion of precise time and frequency measurement <time-nuts at febo.com>
>Sent: Sunday, 21 June, 2009 5:18:51 PM
>Subject: [time-nuts] GPSDO 10 MHz Distribution Amp
>
>In the next couple weeks, I plan on distributing the output of my 
>GPSDO to a pair of Icom transceivers.  I've thought about using a DA 
>like the TAPR TADD-1, but it seems that I can simply split the 
>output of the +13 dBm GPSDO with a Z=50, 3dB equal power divider, 
>that will yield an output of ~ +9.5 dBm to each transceiver.
>
>I can't foresee any port isolation issues that would make 
>necessitate the use of the DA for this application and the 3 dB 
>"hit" in level to each transceiver still seems reasonable for proper 
>transceiver operation.  Am I not considering something 
>important?  Also, I do not want to add any noise with such a 
>distribution that would in any way destroy the excellent phase noise 
>characteristics of my GPSDO.  Thoughts?
>
>Paul, W9AC
>
>_______________________________________________
>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.
>
>
>
>_______________________________________________
>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.
>
>
>------------------------------
>
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