My late friend, N7JEU, was a Marine who operated a mobile high-speed communications post mounted in a jeep. His job was to report where his unit’s last heavy artillery struck. Then he had to change locations before Charlie could get fix on his location. I’ve forgotten exact power, but I think it was three or four watts output.
The rig above is very similar to the one he used.
I met him on the 40-meters one cold October night. I was using a rock-bound Heathkit DX-20. He was using a Hotwater 8.