According to one of the articles 23,870,129.007 Hz +/- 10 Hz. That may have been the measurement limit at the time and the technology. Paul
On Mon, Sep 20, 2021 at 1:15 PM Andy Talbot <[email protected]> wrote: > What's the exact resonance frequency of ammonia? To as many sig figures > as it's been calculated. > Googling just seems to throw up "approximately 23.8GHz" > > Andy > www.g4jnt.com > > > > On Mon, 20 Sept 2021 at 18:10, paul swed <[email protected]> wrote: > > > Well at the very next MIT flea I will grab some 23 GHz waveguide. Maybe > > Nearfest in October. Another trick I have actually used on 10 GHz id 3/4" > > copper tube as waveguide. Its quite low loss but circularly polarized. So > > to use it I needed to rotate the coupling in the shack for best return > > loss. So perhaps 1/2" or 1/4" would be the same. At least in the earliest > > Amonia system they simply seemed to have filled the waveguide with > amonia. > > Then launched 23 GHz down the length of it. Good thing about amonia if > you > > have a wave guide leak you would know it. > > Indeed there is a ton of modern 23 GHz technology available. I was going > to > > make some comments on system oscillators and deleted them. I haven't > looked > > at what types of oscillators or multipliers are out there at a cheap > cost. > > All this being said its a curious possibility. But if its no better then > a > > Cesium not worth any effort. Its one serious advantage is you could > refill > > the amonia. Not really sure what would get used up. I think as mentioned > > here the amonia H would disassociate. > > Regards > > Paul > > > > On Mon, Sep 20, 2021 at 11:07 AM Lux, Jim <[email protected]> wrote: > > > > > On 9/20/21 7:17 AM, Poul-Henning Kamp wrote: > > > > -------- > > > > paul swed writes: > > > > > > > >> Though honestly bending 23 GHz waveguide might be tricky. Or simply > > > leave it > > > >> straight after all it Amatuer grade. > > > > I seem to recall that there was about 10-ish meter coiled up in the > > > > one on the famous old picture. That might be a bit unwieldy. On the > > > > other hand, that was probably not waveguide as much as just plain > > > > copper-tubing ? > > > > > > That would depend on whether you want to control moding. (the picture > > > says rectangular) Bending WG is pretty easy if the radius is large > > > compared to the size of the WG - it's very soft copper, so you just > need > > > an appropriate form around which to bend it. The trick of filling it > > > with sand also helps. At 23 GHz, you probably want to use WR34 or WR42 > > > (Hmm, probably the bigger, so you're farther from cutoff, 17 and 14 GHz > > > respectively). > > > > > > > > > > >> Lastly they discussed an Amonia maser. Never knew. Wonder if it > > actually > > > >> vented amonia slowly. Sort of sounds that way. > > > > I would suspect the main problem with an amonia maser is that the > > > > Amonia disassociates and the hydrogen leaks out though the metal ? > > > > > > > I wonder, though, if you were "building your own atomic clock" whether > > > ammonia might not be easier than Cs or Rb, for instance. These days a > 23 > > > GHz oscillator and other parts are fairly easy to come by, and ammonia > > > is somewhat easier to handle than Cs or Rb. I would normally think you > > > can get any of them by just ordering them, but since ammonia is used in > > > synthesis of methamphetamine, it may not be so easy to get a small > > > bottle of ammonia gas. > > > _______________________________________________ > > > time-nuts mailing list -- [email protected] -- To unsubscribe > > send > > > an email to [email protected] > > > To unsubscribe, go to and follow the instructions there. > > _______________________________________________ > > time-nuts mailing list -- [email protected] -- To unsubscribe > send > > an email to [email protected] > > To unsubscribe, go to and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- [email protected] -- To unsubscribe send > an email to [email protected] > To unsubscribe, go to and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] -- To unsubscribe send an email to [email protected] To unsubscribe, go to and follow the instructions there.
