Trying to find replacement SCR- GFF300E12

Greetings! I'm looking to find a replacement for an SCR/ Thyristor used in a portable X-Ray machine.(Philips PMX-SFR-2) The component is cylindrical (1 1/8" diameter. 1" height, with three quick connect terminals protruding from the top) and a flat surface mount base (no stud). The markings on it show a logo followed by "Japan" and then GFF300E12, a thyristor diagram, then 8662AF. I have tried several electronics suppliers websites with no success. I do not have a spec sheet on it, but the fact it is being used in X-ray suggests that it is reasonably high voltage/current. Any ideas how I might track this down.

Hi Jim,

Have you tried "ECG SEMICONDUCTORS MASTER REPLACEMENT GUIDE". This book is from PHILIPS. My book is a bit too old because the SCR numbers only go to GFE and then it stops. I took 5 numbers starting from 80A to 550Amp so I'm sure that if you get get hold of a later book, you'll be able to find what you are looking for.

SODA