[time-nuts] GPSDO 10 MHz Distribution Amp
Chuck Smallhouse
w7cs at theriver.com
Sun Jun 21 23:53:44 UTC 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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>When replying, please edit your Subject line so it is more specific
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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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>time-nuts mailing list
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>
>End of time-nuts Digest, Vol 59, Issue 74
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