My Sony Xperia Z5 supports EU 700Mhz plan* (I think, it supports bands 12,17,28), even if it's not offered anywhere at the moment. But it also supports 2300Mhz that is supposed to be used for LTE. The problem here is not spectrum, but old systems in use. They could phase out 3G in favour of LTE (better speed) and use 2G for voice and slow data speed.
EU / U.S 700Mhz bands are not compatible.
https://en.wikipedia.org/wiki/United_States_2008_wireless_spectrum_auction
*If they use the same plan as APT countries.
https://en.wikipedia.org/wiki/Asia-Pacific_Telecommunity_band_plan_in_the_700_MHz_band
As for antennas for TV, they are going to receive the signal but the televisions don't do anything with it. The risk is if the strength of the signal is higher than the tuner can handle, resulting in a burnout.
Biting the hand that feeds IT
