Powerful boat anchor radio's from the 1990s. Were used in policing, emergency services and also in production environments. Radio's operate at 110 watts but can be modified to get more power output.
Easily convertible to amateur radio bands including 2 METER, 70 centimeters as well as 6 METER and 10 METER. It would appear the VHF models that operate close to 147 MHz would be the easiest to convert into ammeter radio environment.