Just bought a VHF radio with GPS logging (see title). I had assumed that when you connected a computer to it as a USB device it would be just like a thumb drive. Unfortunately that wasn’t the case.
You can download some special software for PC download (sic) but that doesn’t include Mac or the mighty Linux. So some DDGing later brought me to https://github.com/cr/hx870 which uses python to access it.
It was easy to set up a virtual environment for python 3.6 and use pip to install from the github repo.
You can make sure it is connected to USB, using… lsusb it should show an entry for a device called Yaesu Musen HX890

Then:

Then use:
hxtool gpslog -g yourfilenamehere.gpx or (-j for geojson format)
…to transfer you GPS log from the device to your PC.

Once you have the file safely on your hard drive you can open it using something like QGIS with the GPS tools installed (GQIS -> Plugins -> Manage and install plugins -> (search for GPS) -> GPS Tools (tick it)
Then Vector -> GPS Tools -> [Load GPX File]

By the way to access the setup menu (just in case you haven’t read the manual) hold down the menu/set button for a second or two instead of just tapping it. You clear the log by using the GPS settings menu.