The AM Forum

http://w2dtc.com/w2dtc-mystery-tube-page.htm

Hi Ken,

The mystery tube you have is for producing x-rays.  The disc at the bottom would be made of a particular metal depending on the characteristic wavelengths needed.  They're normally marked with what they are so that the scientists using them know what they're good for.  You might find "Cu", "Mo" or the symbol for one of the other common source materials engraved on the base somewhere.   All you need now is the rest of the system and you can produce some real high frequency stuff!

73,  Dave.

This may be for a gas chromatagraph or spectrometer. I don't do much work over in the lab but I did have one device that I tended to where test gases and unkowns were pumped in over a hot filament.

Hi Dave, G3UUR, I did indeed find the "CU" stamp on the tube. I added two photos to the webpage showing the "CU" if you want to take another look.

http://w2dtc.com/w2dtc-mystery-tube-page.htm

Thank you for identifying the tube as an X-ray tube.  I guess the tube had some sort of a removable anode that slid inside the glass cylinder.

Again thanks for the ID.

73,
Ken W2DTC

Hello again Ken,

Glad I could be of some assistance.  I haven't used lab x-ray sets for many years, so your photos brought back some memories of both happy and extremely frustrating times!  The filaments on the Nonius-Enraf set-up I used in my early years as an academic were forever going o/c and had to be changed.  They were made to be changed, but I remember it was an awkward job. I also had problems sealing the tube, which was mounted vertically with the anode block grounded and water cooled.  The anode was a block of copper, molybdenum, or whatever with an inclined face so that the x-rays generated by the electron stream hitting the anode were not scattered or attenuated by the surface in the direction of take-off.  I don't see an anode block like the ones I used in your photos of the tube.  I remember I had to change the tube to change the anode material.   The filament was held at anything up to -60kV on the set I used, and I could vary the electron stream (anode current) by varying the power to the filament.  I never thought anything about it at the time, but the insulation on that filament transformer must have been pretty good!

I went over to using mainly synchrotron x-ray sources in the mid 1980s and gave up using lab sets pretty much.  I used to do experiments on one of the many synchrotrons at Brookhaven National Lab on Long island quite a lot through the '80s and '90s.  It was the 'Ham shack' there that got me into collecting vintage gear.  It was a time capsule from the '50s and '60s when I discovered it in the late '80s, but in about '91 or '92 some young hams took over the BNL radio club and sold it all off.  I suppose I was lucky to have it to myself for a few years, but was devastated to find it all gone when I returned for my next visit after it had been sold.  I wonder who's got all that lovely old gear now?

73, Dave.