No subject

Sun Sep 12 16:34:46 UTC 2010

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> wrote:

From: W2HX <w2hx at>
Subject: [time-nuts] ok, newbie questions
To: time-nuts at
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"

1. So from reading about this topic on 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.

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.

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.

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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