[time-nuts] ok, newbie questions

[J. Forster]

Certainly in the 1 in 10E9 region a scope is fine.

Set the scope to trigger on the 1 PPS and look at your local 10 MHz at 10
or 20 nS/div. A storage or DSO scope makes this pretty easy. You can tweek
your local osc pretty quickly this way. At 10 nS/div a 1 in 10E9 walks 1
div in ten seconds.

FWIW,

-John

=================


> Well, my 8662A I believe has an 10811A in it.  Hard for me to imagine that
> I
> would be able to see this drift on the scope? But I've never thought about
> it so maybe I need to think more! But I don't mind spending a bit of $ to
> avoid the periodic scope-based calibration process to adjust. Although
> granted, the scope approach seems pretty benign. I'll have to research
> this
> approach more.
>
>
>
> 73 Eugene W2HX
>
>
>
> From: Robert Atkinson [mailto:robert8rpi at yahoo.co.uk]
> Sent: Friday, November 26, 2010 11:47 AM
> To: Eugene Hertz; Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] ok, newbie questions
>
>
>
>
> Hi Eugene,
>
> From your comments and equipment list I guess you are looking for low
> noise
> and stability rather than absolute accuracy. In this case I'd go ro a
> 10811
> OCXO. Check to make sure none of you existing equipment doesn't have one
> already They were commonly fitted as high stab options. For calibration
> you
> can use a GPS with 1PPS output. The Timing versions are best. A quick
> check
> shows Resolution T's and Oncore timing boards available on ebay. There are
> also integrated antenna / receivers (HP/Symmetricom 58534A ) for under
> $50.
> You also need a 'scope. Triggger the scope from the 1PPS. Monitor the OCXO
> output and adjust for zero drift across the screen.
> Next up you will want to look a TBolt ;-).
>
>
>
> Welcome to the Nuthouse!
>
>
>
> Robert G8RPI.
>
>
> --- On Fri, 26/11/10, W2HX <w2hx at w2hx.com> wrote:
>
>
> From: W2HX <w2hx at w2hx.com>
> Subject: [time-nuts] ok, newbie questions
> To: time-nuts at febo.com
> Date: Friday, 26 November, 2010, 4:48
>
> Hi all, I am sure my questions have been asked before. Unfortunately, the
> mailman style archives are so hard to search through. So forgive me my
> transgressions. Happy will I be to get a reference to an old thread that
> answers my questions. Don't need new answers if old ones suffice. (of
> course
> new answers always welcome!)
>
> I am looking for a 10 MHz standard for my lab.  Accuracy/stability
> probably
> wouldn't make a hill of beans difference in the stuff I do, so my
> questions
> are more academic and it's just nice knowing I have a "really good"
> standard.
>
> 1. So from reading about this topic on KE5FX.com I understand that a
> better
> ocxo makes for better phase noise and near-term quality.  I also
> understand
> that some later tbolts had a very good ocxo in them and therefore would
> not
> benefit significantly from an upgrade as ke5fx did using an HP 10811 unit.
> I am considering a thunderbolt advertised on ebay by "flyingbest." I will
> be
> traveling to China (mainland, and Hong Kong) on business the last two
> weeks
> in December so I might save some shipping.  Here is a photo. Can anyone
> tell
> me if this unit has a  "better" 10811-class ocxo or "not so good "ocxo? I
> also understand that not all ocxo's are created equal, even if they are
> the
> same model number.
>
> http://tinyurl.com/2dg2dz3
>
> 2. Other GPS DO units seem to differ on the number of satellites they can
> receive from simultaneously (channels). What is the net effect of having a
> standard that can see 6,8 or 16 birds? Is noise averaged out? Is
> stability/phase noise improved? Here is an example of a 16 sat unit.
> Anyone
> have any experience with this unit? Good/bad indifferent? It seems they
> can
> be had for about $200.
>
> http://tinyurl.com/2ad5kls
>
> 3. And then there is the venerable HP units like this one.  I understand
> this uses the 10811 ocxo. Other than the better ocxo, is there anything
> inherently superior about these HP units to warrant the additional cost?
> Or
> are we mostly just paying for the HP name?  This one is 6 sats.
>
> http://tinyurl.com/24tkwdv
>
> Lastly, my use of a 10 MHz standard will be for use in equipment like
> microwave counters (EIP 548A), Spectrum analyzers (HP 8658B) VNA's (HP
> 3577A, 8753C to 6 GHz), synthesizer (HP 3326A and HP 8662A), premium
> receivers (Harris 590H), etc., etc. For these purposes, is a GPS DO
> advised,
> or perhaps a rubidium standard? For example, I don't need this to power a
> clock. Just a good, clean, stable signal with low noise, low spurs, etc.
>
> What's the overall opinion? THANKS !!!!
>
> (here's to hoping this message looks better than the first two tests I
> made)
> 73 Eugene W2HX
>
>
>
>
>
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