[time-nuts] [Bulk] ok, newbie questions

Fri Nov 26 16:12:54 UTC 2010

Joe,

You are bust greasing an already slippery slope.  :)

-John

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

> Eugene,
>
> Welcome to the list and beware of how 'addicting' this can be.  I started
> out with your exact same purpose, minus all the equipment you have, and am
> still a 'newbie'.
>
> First question is do you want a 'primary' standard (in essence, one that
> does not need to be calibrated) or a secondary standard?  The two
> practical
> choices for a primary standard are a GPSDO and a Cesium Beam Standard.
> For
> a secondary standard, Rubidium based oscillators or a good OCXO would seem
> the most practical.
>
> The Thunderbolt is a good choice and I do not know if the OCXO in the unit
> will make a big difference for your purposes.  It does require +12 VDC,
> -12
> VDC, and +5 VDC though.  I am not a big fan of switching power supplies
> for
> this application.
>
> The Z3805A requires only a single power supply and the Z3816A (at least)
> had
> an option for 110 VAC.  It tracks 8 sats.  A single DC supply is likely
> the
> easiest to build a battery back up for for continuous operation.
>
> You can 'discipline' with a single sat once the site survey is complete
> and,
> again, the number of sats is not likely to be an issue for your purposes.
>
> You may have already found it but you might want to take a look at
> http://www.realhamradio.com/ for additional information about the various
> Z38xxA units.
>
> Beware the shipping fees from Yixun.
>
> And, finally, how will you know when your 'reference' fails?  You will
> probably want to get at least one, if not two, additional units so you can
> leave one running and have another you can bring on line in relatively
> short
> order just to compare.
>
> Hope this helps.
>
> Joe
>
> -----Original Message-----
> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
> Behalf Of W2HX
> Sent: Thursday, November 25, 2010 10:48 PM
> To: time-nuts at febo.com
> Subject: [Bulk] [time-nuts] ok, newbie questions
>
>
> 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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