[rescue] cheap gps for time reference (fwd)

[Dave McGuire]

On July 6, Kris Kirby wrote:
> >   It's a GPS/PLL stablized OCXO.  (Its oscillator is an HP 10811D, which
> > is an impressive oscillator by itself.)  That's a frequency standard
> > by most (if not all) definitions.  It is a long-term standard like a
> > cesium oscillator...excellent long-term stability, not-so-good
> > short-term stability.
> 
> Yeah, but for a frequency reference for general work, poor short term
> performance isn't a good thing. Especially when you are aligning radios
> and such.

  Define "general work".  For aligning radios and such, a rubidium
oscillator (great short-term stability, not-so-great long-term
stability) in a standalone configuration is probably a better choice.
Myself, I use frequency standards as components in "systems", rarely
standalone...to stabilize other oscillators, make longer-term
stability measurements, etc.  The test equipment on my workbench,
though, are all clocked by an OCXO quartz secondary standard.

  For aligning radios, the point is moot...anything more than a quartz
oscillator (or *maybe* an OCXO) is utter and complete overkill anyway.
The vast majority of radio gear doesn't even use ovenized oscillators
for their frequency generation...calibrating a bare crystal oscillator
in a ham rig against a rubidium standard is...ridiculous.

> Isn't Cesium a controlled substance? ;-)

  Absolutely.  But not the Cs-133 that's used in clocks, so far as I'm
aware.  At least, you don't need gov't paperwork to buy one.

       -Dave

-- 
Dave McGuire                  "Needing a calculator indicates that
St. Petersburg, FL              your .emacs file is incomplete." -Joshua Boyd