Hi, Christophe --
All of the 8663As had EFC inputs as far as I'm aware, but not all of the
8662As did. Same for the 640 MHz output.
So if you're setting up an 8662A you'd need to check the option code.
Either that, or be prepared to modify it.
-- john, KE5FX
> -Original Message-
> qu
> Any suggestions on topologies, transistors, white papers, etc? I'm
> considering the NXP BFU590Q silicon bipolar transistor, which I have used
in
> a transformer feedback configuration at 100MHz with less than -180dBc/Hz
> PN.
You could take a look at the approach behind the option-K22 amplifie
> Now, while these measures is performed not on the oscillator itself but
> oscillator and output buffers, unless something is wrong with output
> buffers on either box, the output buffer noise seems to support good
> enough flicker and white noise to support the output of both
> oscillators. Then
> > It would be interesting to know what ADC was used and if there's an
> > SDR-board out there that uses the same ADC.
>
> Uh.. I remember John telling me what ADC it was, but I forgot, sorry.
It uses four AD9265s. The TimePod used four LTC2216s, but the AD9265s
support higher clock rates with
> And then, getting the data reliably out of the ADC into the FPGA, and
> synchronized across multiple channels. That particular part doesn't
> guarantee the startup state of the internal pipeline.
There's a sync pin for use with the clock divider, but AFAIK it does nothing
when the divider isn't
> Is there a _done_ solution to expand a Timepod to
> ~ 100 MHz, narrow-bandish is OK. I'm willing to solder,
> but I'm not ready for yet another development project.
> Not now.
A pair of double-balanced mixers driven by independent signal generators works
well. The mixer RF inputs are driven by
> -Original Message-
> From: time-nuts [mailto:time-nuts-boun...@lists.febo.com] On Behalf Of
> kb...@n1k.org
> Sent: Wednesday, March 25, 2020 9:46 AM
> To: 'Discussion of precise time and frequency measurement'
> Subject: Re: [time-nuts] Noise Floor
>
> Phase noise looks pretty good. ADE
> b) if I want to measure 1e-11 or even 1e-12 at 1sec - what resolution does
> my counter need? If the above was true, I would expect that a 1ps
> resolution (and an even better stability!) was required to measure ADEV of
> 1e-12, The fact that the (as far as I know) world's most recent,
> rocket-s
> -Original Message-
> From: time-nuts [mailto:time-nuts-boun...@lists.febo.com] On Behalf Of
> Bruce Griffiths
> Sent: Friday, May 15, 2020 4:32 PM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] f-multipliers from VHF to 10 GHz
>
> Indicative price:
> I've been trying to figure out how the error estimates (error bars) in the
> XDEV traces in TimeLab are computed. The status bar says " +/- sigma /
sqrt(n/
> m)", obviously "n" is the number of values in the bin for the computed
tau,
> but what is "m"? It cannot be smaller than "n" as the error e
> Then, M = tau / tau0? So, for a time series with a measurement interval of
1s,
> M would be equal to tau, right?
Exactly. And if the sample interval were 0.1s, then M would be 1 at t=0.1s
and 10 at t=1s.
-- john
___
time-nuts mailing list -- time-n
> To a first order, the ADC is like an ideal multiplier/mixer - phase noise on
> the
> clock contributes to phase noise on the sampled data by reciprocal mixing,
> just
> like a mixer.
The ADC-as-mixer metaphor is a useful abstraction, but a leaky one. Here's the
way I think of it: while all m
> -Original Message-
> From: time-nuts [mailto:time-nuts-boun...@lists.febo.com] On Behalf Of
> Gerhard Hoffmann
> Sent: Saturday, October 17, 2020 5:59 AM
> To: time-nuts@lists.febo.com
> Subject: [time-nuts] Fwd: cheap frequency extension for timepod
> . . .
> I have 2 17 dBm SRA1-WH, but
> FWIW I seem to recall that TWO shortcuts appear on the desktop
> after installing LH. One goes to a GPS unit in Seattle that you are
> accessing online. The other is YOUR local unit.
>
> Gordon WA4FJC
Correct. If you log on to the test server and force it to accept your
specified latitude/lo
If you're looking for a low cost surplus GPSDO, the ones Tom mentioned in
his post on Saturday are the ones you want. Not a Thunderbolt-E, and not
something from the China surplus/e-waste market.
-- john, KE5FX
> -Original Message-
> From: Robert DiRosario [mailto:ka3...@comcast.net]
> S
> Again, this is analogous to the 5071A having 1 MHz
> spurs of about -90 dBc, yet the ADEV is not much
> different than an open loop 10811. How high would
> the 1 MHz spurs have to be to affect ADEV?
With ADEV, you have to consider the measurement bandwidth before you can ask
questions like this
> -Original Message-
> From: time-nuts [mailto:time-nuts-boun...@lists.febo.com] On Behalf Of
> Richard (Rick) Karlquist
> Sent: Sunday, September 02, 2018 6:12 PM
> To: Discussion of precise time and frequency measurement; Forrest
Christian
> (List Account)
> Subject: Re: [time-nuts] PLL/G
> Has anybody tried the AD8003 (triple video line driver amplifier) for use
as
> distribution amplifiers? It looks to me like this part might be a decent
> choice...
I don't have any NF or residual PN numbers handy for the triple-amp
versions, but the single-amplifier part from the same family (A
> -Original Message-
> From: time-nuts [mailto:time-nuts-boun...@lists.febo.com] On Behalf Of
> Anders Wallin
> Sent: Saturday, December 15, 2018 9:03 AM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] new op amp for distribution amplifiers
>
> Hello G
> So the THS3491 is an LMH6702 replacement except
> for a slightly elevated noise floor. Why would
> anyone not want to use the LMH6702? What does
> the THS3491 have going for it?
Power output is what caught my eye. After the loss in the series termination,
the LMH6702 struggles to put out +15
> Stylish dead-bug! ;)
> On my board I increased Rf/Rg to 4k7, to get rid of the gain-peaking.
> With 4k7 resistors I see +20 dBc/Hz worse phase-noise with the THS3491
> compared to LMH6702 :( (image attached)
> If noise power scales with the resistors then it explains about 4k7/200R =
> 14 dB, fo
> I have been observing the relative time stability of a Jackson Labs Ln Rb
GPS
> disciplined oscillator and a 5071A cesium reference (undisciplined) , as
> measured via the 1 PPS outputs and a TIC. See the attached plot for about
8
> days of history. Horizontal axis is seconds and vertical axis is
Said at JLT isn't currently on the list so I'll forward his input:
--
. It looks like you are measuring the output of the OCXO or TCXO
inside the LN Rb. That unit has a tempco spec of 20ppb over its operating
temperature, the Rubidium is much much better of course (up to
To some extent, since JLT doesn't make the rubidium MAC module itself, they
are subject to whatever performance limitations are inherited from the OEM.
Holdover specifications don't involve thermal shocks, and the telecoms
rarely want to pay extra for performance beyond the requirements. I agree
t
> http://www.ke5fx.com/lnrb_18hrs_phase.png
>
> No excursions beyond +/- 10 ns so far, we'll see how it does over the next
> few days.
Something else I should note is that the 'house clock' GPSDO in the magenta
trace (a) is very well-shielded from airflow in an unventilated rack
enclosure; (b) ha
(Forwarded message from Said below)
-Original Message-
From: Said Jackson [mailto:saidj...@jackson-labs.com]
Sent: Tuesday, February 05, 2019 4:25 PM
To: 'John Miles'; 'Discussion of precise time and frequency measurement'
Subject: RE: [time-nuts] LN RB
Gents,
We h
> A friend of mine has a x96 multiplier from 108 MHz to 10 GHz but we don't
> have access to any counters capable if measuring the difference.
For sanity-checking an extremely small frequency discrepancy, perhaps you
could set up the DDS to output a signal very close to a plesiochronous
reference
> Hi all,
> I have not found details about the new product of the Jackson Labs, the
> Phase Station.
> The new driver is now added to the V1.32 Beta version of Timelab.
> It seems to be an alternative of Timepod.
> Can anyone anticipate something?
The PhaseStation 53100A can be thought of as the
> Wow, light years ahead of the Keysight system.
> At HP/Agilent/Keysight, this would be called
> a doomsday machine. This should put Keysight
> out of the phase noise business, probably
> permanently. If I still worked there, it would
> be fun to hear the debate between the bosses
> and the R&D
> As to your analogy, it is valid only if and to the extent that NIST-F2 has
> practical applications. That is what I am asking about.
The important thing about devices like NIST-F2 is not that they are better
than any other clocks, it's that they are still imperfect. The researchers
are studying
> My guess is well into 6 figure$.
It's a modular system like its 3048A and E5500-series forebears, so the only
limits are your imagination and your bank account. :) Very cool hardware,
noting that it has some competition from all-in-one instruments like the FSWP
that the earlier 'doomsday mac
> In the case of Power-Pole connectors, as someone else described, the
> exact placement and alignment of the crimp, and how the terminal deforms
> during the crimp, is important to successful insertion of the crimped
> terminal into the plastic shell where the contact-force leaf spring
> retains t
> I have searched the posts on this but am still unsure of how to transfer
the
> data to PN.exe. I can find no native interface for ADC samples.
Yes, that's the dreaded "exercise left to the student." :) Currently there
aren't any good plug-and-play solutions for baseband acquisition in either
PN
> This 5061B was working fine until a recent power failure, after which the
unit
> would not come on line (alarm light stayed lit).
>
> Major symptoms now...
Have you checked the continuity of the hot-wire ionizer? It may have opened
up like a light bulb filament when the power came back on.
> So, with a 5 MHz source, a RF generator that is doing DCFM lock of PLL
> and then analyse spectrum of that, that fails to lock this PLL loop, and
> I fail to get a monitored beat note that makes sense. So, I was hoping
> someone had done this and could help me with the teething problems. Once
> t
> I think you may be heading a bit off track digging into the 5120. The
> 53100a has a very different “heritage” than the TSC gear. The 5330
> “TimePod” would be a better thing to dig into to see its history. I’m
> guessing 52100A is a typo.
>
> The .TIM files are generated by TimeLab so that’s a
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