The RF output power adjustment in the AMT5000 part 15 transmitter from sstran.com has creative applications.
The RF power control of course was designed so the user can adjust for precisely 100 mW, but it has other uses besides.
For strictly indoor AM listening I back the RF power down to 36 mW (minimum power) which is just exactly enough to cover the interior without reaching other neighborhoods, although at such a low level it provides a real DX challenge for distant listeners.
While dabbling in the yard 36 mW is slightly more fragile for portable listening but still useful, although I usually crank up to 100 mW for solid yard coverage.
The high side reaches nearly 400 mW but getting up there would be wrong so I prove my trustworthiness by never doing it.
I hear about people struggling with other transmitters and I have to ask myself, "Why? Why do they torture themselves?"