Earlier quoted context omitted.
If it were me, the antenna would be a few hundred feet away from the equipment. And the antenna wouldn’t be anything like an antenna, just something that looks like a lawn-chair. And I’d move it every day or two. And definitely not run it 24h!!! Could still be found, but good luck.
Hmm, then you need a super-mega-amplifier tacked on to boost the signal over the cable (AFAIK, the frequencies used really like short antenna runs). So that then means a super-thick faraday cage around the actual device, and probably somewhat noteworthy power consumption (a battery certainly wouldn't be enough).
So after counter-side finds your camouflaged BTS, it is only disposable and relatively cheap part and doesn’t lead to whole operation uncover.
That probe part then would connect to starbucks wi-fi and interact with BTS software somewhere far from physical location, so you can’t quickly trace channel between probe and spy team.