Jeff Liebermann wrote:

...
Others have suggested cut-n-try which is probably good enough. As
long as the coil looks roughly like the original, it should work.
...


Yeah, working as a software engineer and finding I get the most money
from convincing those "with money" that I am worth "some of their money"
has made me aware of the value of reverse engineering--whether software
or hardware--it works!

But, if you have built enough "old box tube xmitters", you can almost
guess the dia./turns/and-caps wink Heck, bet I could come up with a
circuit using the same coils, using a fet, and saving the cost of the
filament power! Indeed, if the tube uses an octal socket, in his current
GDO, why not replace the tube with a fet(s)?

Regards,
JS