Ed,
On 04/29/2012 12:11 AM, Ed Palmer wrote:
Paul,
On 4/28/2012 1:26 PM, paul swed wrote:
Ed
Several comments
Great pix with the right level of detail to actually see and analyze
stuff.
Second what a find you have there. A real mans RB nothing small about the
gas cells.
Exactly. I can use this as an experimental platform for various changes
& enhancements. Even an FRK would be awkward to start hacking on.
Indeed. These larger rubidiums is much more fun in that respect.
The color of the lamp is way off to my thinking and what I have seen.
That
color tends to be from a non heated RB. But I need to be very careful
with
that comment. Perhaps the gas mixtures simply a bit different and so the
color would be different. Also its not as bright as I might expect.
Agreed. The color is mostly due to my cheap camera trying to white
balance something with no white! It's also possible that the color has
shifted over 40 years due to outgassing, leakage, and absorption of Rb
into the glass - notice how brown the glass is in the picture of the
bare lamp. Also, the temperature would be off since the lamp was
somewhat out in the open. I tend to agree with your assessment of the
intensity. I'm surprised that after 40 years it's as bright as it is.
Some years ago Corby mentioned that Tracor lamps usually last for only
10 years. Unfortunately, this unit doesn't measure the photocurrent so I
don't know how much it's faded. I measured the voltage across the
photocell and got 10 mv across 100 ohms, but that's almost meaningless
without a working unit to compare it to.
The purple/pink colour is expected. Using Xenon in Rb lamps is common,
and it has been found that running the lamp in mixed mode, i.e. both
rubidium and xenon emission, provides a stable and low noise source.
Xenon can be filtered easily, so the S/N can be kept good in that
aspect. The hotter Rb only mode of the rubidium lamp provides a higher
light-intensity pulling and also is a bit more unstable to control the
light level over time.
So, pink is expected.
Noting the various components its quite possible they have drifted in
value. Like the transistors thats an age that they would tend to do that
over 30-40 years.
I've been watching for that, but haven't seen any problems so far. Even
the Ta capacitors and Ge transistors are all good. The only component
change I noticed was the main power supply capacitor.
Lastly your bench
Nothing like a bench jammed with Stuff. Comfortable.
It's possible that the bench has rotted away and the stuff is
self-supporting. I'm not sure and don't really want to know. :-)
What you don't know doesn't hurt you...
Sorry to say I have seen those pins and have no clue how you might find
them. Hamfest flea market stuff?
AFAIK, there's no such thing as a hamfest within 500 miles of here.
Maybe just as well.
I seem to never get informed, but not being a ham helps.
Cheers,
Magnus
_______________________________________________
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.
