Re: [time-nuts] backfill

Poul-Henning wrote: Next down the line is hydrogen, which comes with a shitload of issues. No argument there. But other methods all have their own shitloads -- it just depends on which shitload the designers dislike the least. you will find little love for hydrogen cooling [today] In

Re: [time-nuts] backfill

My memory of high vacuum work is that you need to pump for 4 hours at 300C to remove the water monolayer from glass. On top of the that water monolayer is another water monolayer that comes off more easily, and on top of that another……….. cheers, Neville Michie > On 9 Jun 2017, at 10:57 AM,

Re: [time-nuts] backfill

alpha quartz to beta quartz phase transition at 573C amongst other factors. Bruce > > On 10 June 2017 at 12:31 Hal Murray wrote: > > > > > > You can’t quite process a crystal at 300C, but you can get close. > > > > > > What happens if

Re: [time-nuts] backfill

> You can’t quite process a crystal at 300C, but you can get close. What happens if you get it too hot or too long? What's the limiting factor? -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To

Re: [time-nuts] backfill

Hi You can’t quite process a crystal at 300C, but you can get close. Bob > On Jun 9, 2017, at 7:38 PM, Neville Michie wrote: > > My memory of high vacuum work is that you need to pump for 4 hours > at 300C to remove the water monolayer from glass. > On top of the that

Re: [time-nuts] backfill

Hi Well one thing that happens is that the glue that holds the blank in the holder turns to ash …. Bob > On Jun 9, 2017, at 8:31 PM, Hal Murray wrote: > > >> You can’t quite process a crystal at 300C, but you can get close. > > What happens if you get it too hot or

Re: [time-nuts] PPS sync

je...@hanler.com said: > It’s interesting how it jumps around from PPS to PPS. You can work out what the offset will look like. Assume your clock is roughly 10 MHz. So you divide by 10,000,000 to get a PPS. If your clock is 2.001 HZ fast, then you need to divide by 10,000,002. That

Re: [time-nuts] backfill

Bob wrote: In this case hydrogen + oxygen (like from oxidized metal) goes to H20. You very much do not want water running around inside your crystal holder… Helium is inert. The insides of mains alternators are almost entirely metal -- tons and tons of copper tubing, and the casings and

Re: [time-nuts] backfill

Hi Cold traps and vac-ion pumps were very common on precision crystal seal setups 50 years ago. They have gotten better since then…. Bob > On Jun 9, 2017, at 9:13 AM, jimlux wrote: > > On 6/8/17 1:19 PM, Bob kb8tq wrote: >> Hi >> >> If you look at the thermal

Re: [time-nuts] backfill

Hi My guess is that crystals are more sensitive to moisture than the alternators…. The level of “clean” you need in a precision crystal enclosure is way beyond what is required in a number of other areas. One layer of water molecules is way to much in a modern crystal. can and do use

Re: [time-nuts] backfill

It is possible that the ageing of a crystal is associated with the redistribution of the surface water monolayer, under the influence of the minute temperature gradient of an oscillating crystal. Some energy is dissipated in the quartz, so some gradient may exist. When a crystal is resting, the

Re: [time-nuts] backfill (was: Poor man's oven)

The difficulty with hydrogen is to keep it where you want it. It does not take very much for it to leak out (or in, as the case may be) On Jun 8, 2017 4:58 PM, "Alan Melia" wrote: > Hi Bob, it also depends on what you allow to leak into the vacuum. > Hydrogen is a

Re: [time-nuts] backfill (was: Poor man's oven)

Wouldn't the low density of helium reduce some mechanical friction? I realize the motions are small but they are motions. The "Cousteau effect"? :) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to

Re: [time-nuts] backfill

On 6/8/17 1:19 PM, Bob kb8tq wrote: Hi If you look at the thermal conductivity vs very low pressures, the conductivity comes up pretty quickly from a hard vacuum. There is essentially no impact on Q. basically, when the mean free path gets to be shorter than the distance to the wall, the

[time-nuts] Symmetricom Time Source 2700

Just got a Symmetricom Time Source 2700. Bought it for the PRS 10 to keep. . It came with a 48 V power source. Does any one want the rest of the Unit. You pay shipping. Please off list. Bert Kehren Palm City Fl/ ___ time-nuts mailing list --

Re: [time-nuts] backfill

In message <593a4677.5080...@yandex.com>, Charles Steinmetz writes: >The insides of mains alternators are almost entirely metal -- tons and >tons of copper tubing, and the casings and rotor shaft are steel. And >the alternators must operate at a relative humidity of absolute zero.