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

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@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 > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/ > mailman/listinfo/time-nuts > and follow the instructions there. >

Corby Congratulations on keeping the Maser going. Pretty amazing. You should check it against wwvb to make sure its accurate. Chuckle. Regards Paul WB8TSL On Mon, Jan 2, 2017 at 2:42 PM, Tim Shoppa <tshoppa@gmail.com> wrote: > 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@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 > > > > _______________________________________________ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to https://www.febo.com/cgi-bin/ > > mailman/listinfo/time-nuts > > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/ > mailman/listinfo/time-nuts > and follow the instructions there. >