According to the datasheet, those things are microwave tubes, for use at centimeter wavelengths. Don't know how well one would work at HF. Might be a good tube for VHF or UHF though. Wonder if anyone ever tried AM on the 70 cm band?
What does its frequency range have to do with anything? All that sets is the upper limit and the tube could be used at DC or audio if desired. There are numerous UHF capable tubes in use at HF already.
The GI-7B would likely be a better AM tube than SSB since its IMD performance is not very good.
Carl