One (hopefully final) thought.
In the days when information was difficult to come by, Tomer collected much of the important lore that was only known to designers and repair technicians, and then distilled it into a form written in the vernacular and comprehensible to non-engineers. This was a laudable and valuable accomplishment, and, judging by the number of copies sold, it surely assisted many hobbyists and technicians in understanding, repairing, and building equipment using vacuum tubes.
Books like the Radiotron Design Handbook, to contrast, are a technical tour de force, of course, and remain so even to this very day, but the content was likely not accessible to ordinary people without specialized knowledge or training, including the technicians who simply wanted to fix equipment, understand and evaluate options, and extend the lifespan of their tubes. The local bookstore likely did not carry RDH but it would have carried Tomer in the section with home and auto repairs. I remember even in the 1970s that bookstores carried limited volumes and one simply had to know that a book existed to have it ordered. This continued into the 1980s and early 1990s.
Consider how dark the times were when Tomer was writing. For example, I note that the surgistor, a thermistor with a bi-metallic switch (heat eventually closes the switch), was added to series-string heater equipment—televisions and radios—extend the tube lifespan by reducing heater inrush current. This (to us) obvious tweak was really only known to repair techs and savvier consumers, but one had to be in the cognoscenti to have access to such information. It was available in the repair shops and hardware stores for consumers to add. I know my dad added those to our televisions which were not so equipped and he explained to me why this was necessary.
(The conversation went roughly like this. Me: But if saves the tubes why doesn't it already come installed? Him: Because the manufacturer saves money by leaving it out and it doesn't care if I have to buy tubes more often. Me: But that's wasteful! Him: (nods) My grandfather once told me that this country was founded upon massive waste. Get used to it because it isn't going to change.)
We now have a firehose torrent of information which Tomer would have viewed, I believe, with amazement and incomprehension. He laboriously and tediously assembled information is readily accessible in minutes to anyone with a search engine.
I again suggest anyone reading Tomer as a definitive source consider which areas remain true to this day, and which, like the cautions on fixed bias, were an artifact of the times in which he wrote or which afflicted particular designs. Tomer clearly and concisely identifies issues which ought to be thought about and researched. I cannot think of a single issue Tomer raises, including the merits and risks of fixed bias, which should not be carefully considered and pondered by anyone involved with vacuum tube equipment.
You may not reach the identical conclusions which Tomer did and promoted, but the exercise is valuable as it improves understanding. Circuits do what they do, not what we want, and the more we know about the risks and rewards the more informed our decisions become.
Take your own informed counsel instead of relying upon dogma.
. In fairness i try to do the math. Practice makes it easier. I try to follow blazed paths when i can though
