[MSA-Talk] Replacing old Phillips XRD MA stabilizer?

[Henry Barwood]

Would anyone happen to have a schematic on how to replace the Ma
stabilizer on an old Phillips XRG 2000 generator with a rheostat? I do
not need stabilized Ma, since I'm only going to use the unit for XRD;
however, I have only a vague idea of how to do the re-wiring and would
love to have a guide.

Something has died in my stabilizer and it runs away and blows the F3
fuse (.5 amp) after about 1-2 minutes of operation. If anyone knows a
fix other than replacing the unit, I am open to suggestions. Thanks.

Henry

--
Henry Barwood
Professor, Earth Science
Department of Chemistry and Physics
Troy University
Troy, Alabama 36082


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[Larry Finger]

On 09/09/2013 01:02 PM, Glenn Waychunas wrote:
> Hi Henry:
>
> I think your tube was gassy and that is why it took so much current. As Rex
> stated, the filament in the tube is likely OK. There used to be a protocol for
> slowly bringing up older tubes--which allowed some self-gettering in the tubes.
> However likely you cannot use this. I suspect the ma stabilizer is OK. The
> system can be checked with a dummy load that behaves like an x-ray tune more or
> less.
>
> Philips should be able to hep you with schematics and suggestions. If not you
> might contact Dave Rognlie at Blake Industries in New Jersey if he's still
> around. Maybe he or his technician can help. The old Philips generators were
> not too hard to fix as the components were easy to reach. Hence a decent
> electronics tech could fix it. Modern units need factory-trained people to service.

The most-common problem with those MA regulators was a bad 2D21, which is the
only vacuum tube in the stabilizer.

Larry

[Glenn Waychunas]

Hi Henry:

I think your tube was gassy and that is why it took so much current.  As Rex stated, the filament in the tube is likely OK.  There used to be a protocol for slowly bringing up older tubes--which allowed some self-gettering in the tubes.  However likely you cannot use this.  I suspect the ma stabilizer is OK.  The system can be checked with a dummy load that behaves like an x-ray tune more or less.

Philips should be able to hep you with schematics and suggestions.  If not you might contact Dave Rognlie at Blake Industries in New Jersey if he's still around.  Maybe he or his technician can help.  The old Philips generators were not too hard to fix as the components were easy to reach.  Hence a decent electronics tech could fix it.  Modern units need factory-trained people to service.

Best wishes

Glenn

--
Glenn Waychunas

Senior Scientist
Earth Sciences Division      Geochemistry Department
Lawrence Berkeley National Laboratory  MS 74-316C
One Cyclotron Road  Berkeley CA 94720

GAWay...@lbl.gov
Office:  Building 74 room 207
Laboratories:  Building 74 room 227 (Interfaces), Building 74 room 229 (Nanogeoscience)
Phone  510-495-2224
FAX 510-486-5686
Cell 650-400-3595