I had the privilege of meeting Frank James at the very end of his career at CERN. I came to CERN as a technical student in the radio-frequency group in 1985, the year of Frank’s retirement, and I clearly remember how kind and helpful he was with the young inexperienced person that I was at the time.
I remember him as a very open and always positive person, ready to provide good advice and to help me in finding out the instrumentation that I needed for my thesis work.
The “Frank James” amplifier was a unit that he developed for the new linac, Linac2, between 1975 and 1979.
The design done by Frank was quite standard, but when building the device, he encountered a lot of technical problems that he had to progressively solve, coming out with a very sophisticated and reliable unit that everyone started to call “the Frank James”.
The ”Frank James” had been reproduced in a dozen units and has faithfully and reliably served in the RF system of our linacs for 39 years, until Linac2 was finally switched off in 2018. If you happen to come to Geneva, a few “Frank James” are still visible in the old Linac2 building.
We have a few former colleagues who reached such an age. What they have in common I think is a wide intellectual curiosity and a positive spirit that keeps them motivated in their old age. Frank fully had all these qualities.
Please forward all my sympathy to Frank’s family, personally and on behalf of CERN and of all his former colleagues.  
Best regards,
Maurizio