This is always an area where hams have difference of options. Some will say that Portable means that you are not at home. If was a station that moved from someplace else and would later move back to where it came from.
setting up an Amateur Radio station at the summer cottage for two weeks using a dipole in the trees that would be portable.
sitting at a camp site in the woods with a qrp lash up hooked to a wire antenna or antenna you had to set up that would be portable.
a station mounted in a car, boat, airplane, motorcycle or carried on your back hooked to a mobile antenna that was mounted on the car, boat, airplane motorcycle or your backpack
that can be used while moving, that would be mobile.
First the rules, There are none! I could find anything in Part 97 that defines Mobile or Portable. There is some talk about Maritime Mobile but the rules do not even define that.
PART 97—AMATEUR RADIO SERVICE
§97.3 Definitions. There is no mention of Portable or Mobile in the definitions.
One definition that I have seen used is around the internet and forums is that Portable is a station moved to a fixed location and operated while stationary. A station in a big van, like an EMS field command station. Mobile is using the radios in your car, boat, plane, et cetera while driving.
In the UK the rules attempts to define /M or /P.
When operating at locations other than the Main Station Address, it is recommended that the following suffixes be used:
- If the Licensee operates the Radio Equipment at an Alternative Address, the Licensee may use the suffix “/A” with the Callsign;
- If the Licensee operates the Radio Equipment at a Temporary Location, the Licensee may use the suffix “/P” with the Callsign;
III. If the Licensee operates the Radio Equipment from a Mobile location, the Licensee may use the suffix “/M” with the Callsign;
We see that the choice of suffix depends only on the “location” of the equipment. Another important point is that these suffixes are only “recommended”. You “may use” them, or not.
So should you use /M or /P in the USA? I say yes and I subscribe to the definitions that portable is a station moved to a fixed location and operated while stationary. A station in a big van, like an EMS field command station and that Mobile is defined as using the radios in your car, boat, plane, et cetera while driving.
But that is just my opinion and you can have your own since Part 97 doesn’t tell you what to do.