[time-nuts] R&S XSRM Rubidium

[Magnus Danielson]

On 01/22/2011 11:31 PM, paul swed wrote:
> Well pretty interesting late afternoon.
> The oscillator works but C-11 definitely is troubled. Additionally a key
> element is an effective ground. Bridge the low side of the ampule to a
> better ground and the oscillator seems to reliably start. Ignition occurs
> when the oscillator is in the 80-85 MC range. It can tune from 65 to 130 MC.

Interesting. I tuned for maximum amplitude. Seemed to work well enough.

> Now the neat part.
> That 1-2 mm silver dot that I see in the ampule. When warm it actually moves
> around as you tilt the lamp assembly! Like  drop of water would but very
> slowly. So I think this is the RB Magnus speaks of. I will need to peel the
> mica cover off the area to try to heat this up and return it hopefully to
> use.
> The fact that the dot moves means I may be able to get it to the center of
> the sphere to more easily heat it.
> Magnus when you heated yours did it simply vaporize??? Or did you get it to
> simply move down deeper in the core area?

I was quite brutal. I didn't remove it from the back-piece and mica, I 
just heated it up as it would be horizontally oriented. I used the 
end-piece and removal-tool as cool-off area and mechanical holder. I 
simply just heated it as it was heated in the oscillator the first time. 
Then I got the grey surface of the glas. Darn. Next I thought that I 
would let the got gas evaporate up in the colder corner... so I oriented 
the open glas downwards and let it remain in the holder, heated it 
properly up and saw the grey completion disappear, stayed on it with the 
heat somewhat longer and then just turned the heat off and let it sit 
there and cool down. When it had cooled down (I was able to hold the 
removal tool fairly quickly, so it was acting as an OK cooler) I looked 
into the lamp and could clearly see the rubidium blob right in the 
middle and no more splatter. Nice and clean.

> Other thing, measuring ignition time. On the first run just for the heck of
> it I flashed a led light into the ampule and it ignited instantly. So
> perhaps for old hard starting end of life RB lamps this might be a trick to
> at least get it going for a bit longer.

Hehe.. we are starting to have fun now. :)

Cheers,
Magnus