Makers of the Spitfire 100 mW AM Transmitter also make the Mosquito 1-Watt AM Transmitter, and if it had a variable power adjustment that allowed reduction to 100 mW, I would order one immediately so that it could be operated legally here in the U.S., with reserve power available if the FCC ever allows raised AM field strength, also making it possible for me to experiment in search of the precise power that would provide full-quieting at night over the same area experienced during daylight.
The schematic diagram is shown in the manual showing no power variability and no parts list.
Another 1-Watt AM Transmitter made by Vintronics can be found on Ebay, but also with no power varying control.
I didn't know the Netherlands allows 1 watt. I don't think this is a world wide trend as mentioned but maybe the FCC should take a look. But I think over there the AM band is hardly used and the commercial stations don't care as they are not on it. I didn't think any country in the European Union as shown in the other countries rules allowed any unlicensed use and the one watt could need a permit of some kind. In fact it does according to this and you are assigned a frequency. You can have 1-5 watts.
https://swling.com/blog/2016/01/netherlands-proposal-to-open-mediumwave-band-to-low-power-stations/
I have to wonder, how come the Vintronics can be had for $140 USD and is one watt when the Procaster and the Rangemaster for example are $695 and up to $1200?
There has to be a catch, and they are not made in China. Just wondering about the quality.
I like they have a UK warning that a license is needed but nothing mentioned about using this in the USA.