I think if their jamming goes up to 3 GHz, the sidebands of the jammer might affect at 3.4 GHz too, but yeah, there is also that one.
The problem with making your own RF systems is that Ukraine would require a steady supply of RF components, which might be hard to secure in war time over off the shelf, which probably have stocked supply lines in most places, through hobbyists stores.
I think if their jamming goes up to 3 GHz, the sidebands of the jammer might affect at 3.4 GHz too, but yeah, there is also that one.
The problem with making your own RF systems is that Ukraine would require a steady supply of RF components, which might be hard to secure in war time over off the shelf, which probably have stocked supply lines in most places, through hobbyists stores.