Originally Posted by
pangolin
I think you are wrong about mode C being inoperative. When I was in a known jammed area I asked atc if they had our ADS -B and they said no but they still had mode C.
Depends on the spectrum(s) involved, and the power at your location.
GPS signals are pretty weak, I don't know for sure but strongly suspect that mode C (and other modes) will take more power to jam than GPS. GPS is probably always going to be the weak link in terms of which systems are susceptible to jamming or other interference. That and sat based wifi
