[time-nuts] EFOS2 MASER turns 34!

Tim Shoppa tshoppa at gmail.com
Mon Jan 2 14:42:23 EST 2017

Very nice report, Corby!

When I was in grad school back in the 90's, doing vacuum pump work was a
very menial task usually assigned to grad students, so naturally I became
quite familiar with it :-). Especially cleaning up messes with decrepit old
experimental systems!

I think back to those days and maintaining an already-functioning H-Maser
actually seems perfectly feasible in the long term.

The tight geometry of the copper package of a H-Maser sure seems a lot more
feasible than the other atomic clocks which are way more hi-tech stuff.
That said, machining the copper would be way beyond my ability!

I also did get to work some plasma physics experiments where we used
kettles - literally large industrial cooking kettles, with some hacked-in
brazed-shut machining for the various probes and plumbing. Maybe if there
was some way to homebrew a primitive H-Maser with that low level of
construction competence I could give it a try!

Please share more tales/pics of your H-Maser experience!

Tim N3QE

On Mon, Jan 2, 2017 at 1:18 PM, <cdelect at juno.com> wrote:

> Happy Birthday EFOS2 Maser!
> The EFOS2 active hydrogen Maser at my place just turned 34 years old!
> Pretty impressive reliability.
> It is an Oscilloquartz Maser, they are now called T4 Science.
> I know a guy in Norway that bought the refurbished EFOS3 Maser last
> year directly from T4 Science! It is 32 Years old!
> I have had the EFOS2 running here pretty much continuously since
> Sept 2007.
> I've had to refill the Hydrogen bottle 3 times.
> replaced ion pumps 4 times (requires a CLEAN vacuum pumping system)
> Had to repair one of the ion pump supplies (bad capacitor)
> Also removed original 1 transistor power oscillator that was used to
> drive the discharge providing the atomic Hydrogen.
> I replaced it with a custom class A oscillator amplifier.
> It uses an Oscilloquartz B5400 Quartz oscillator that has aged very
> little since 2007!
> Cheers,
> Corby Dawson
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