{"id":4222,"date":"2026-05-13T05:39:26","date_gmt":"2026-05-13T12:39:26","guid":{"rendered":"https:\/\/www.rbdinstruments.com\/blog\/?p=4222"},"modified":"2026-05-13T05:39:28","modified_gmt":"2026-05-13T12:39:28","slug":"20-610-electron-gun-supply-hv-offset-potentiometer-modification","status":"publish","type":"post","link":"https:\/\/www.rbdinstruments.com\/blog\/20-610-electron-gun-supply-hv-offset-potentiometer-modification\/","title":{"rendered":"20-610 Electron Gun Supply HV offset potentiometer modification"},"content":{"rendered":"\n

The 20-610 Electron Gun Supply provides the electron beam high voltage for the PHI 600 and 660 scanning Auger systems.  As part of the energy linearity and elastic peak calibration, R108 on the high voltage control board in the 20-610 must be adjusted.  To adjust R108 the 20-610 needs to be pulled out of the electronics rack and the cover needs to be removed to gain access to R108.  This blog post shows how to install a modification to the 20-610 that allows R108 to be adjusted from the front panel without needing to pull out the unit or remove the cover from the 20-610 unit.<\/p>\n\n\n\n

Parts needed:<\/p>\n\n\n\n

3 pin male and female micro pin connectors (available at Digikey, Amazon, eBay\u2026)<\/p>\n\n\n\n

5k ohm 10 turn precision panel mount potentiometer<\/p>\n\n\n\n

Vernier dial with lock<\/p>\n\n\n\n

3 feet of thin wire 24 to 30 AWG)<\/p>\n\n\n\n

Solder and heat shrink<\/p>\n\n\n\n

Soldering iron and solder sucker or copper braid<\/p>\n\n\n\n

Procedure \u2013<\/p>\n\n\n\n

Make sure that the 20-610 electron gun supply is turned off and unplugged.<\/p>\n\n\n\n

Remove the 20-610 from the electronics rack. You will need to remove the large high voltage cable and the small Remote Programming connector.<\/p>\n\n\n\n

Remove the cover from the 20-610<\/p>\n\n\n\n

In the space between the power switch and the Beam Voltage meter find a spot that is centered and drill a 5\/16″ hole using a stepper drill. Make sure that the potentiometer will clear the Beam Voltage meter and the power switch -measure twice!<\/p>\n\n\n\n

Prep the 3 pin connectors by soldering wires to each pin and using heat shrink to insulate the exposed pins. The wires should be about 6″ to 8″ in length.\u00a0 The purpose of the connectors is to be able to separate the 100 Control board from the front panel potentiometer in case the 100-control board ever has a problem and needs to be removed to troubleshooting.<\/p>\n\n\n\n

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