[Amps] the radio handbook by mr orr w6sai and amps

[Ian swain]

Hi guys

I have a question about the radio handbook by w6sai

Is this book like the arrl handbook in regards to the different
editions and content not changeling much over the years in any
great deal ?

Why I ask is I have 23ed book here which i don't own but would
like to get a copy of for myself.  I find the section in the book on
amp's of most interest :)

Is there much change of the amp section in this book over the last 20
years ?..

regards
Ian
zl2ias