Rather trivially, as any superheterodyne receiver from has an intermediate frequency oscillator that is mixed with the signal - and it is hard to not emit RF from that.

Modern equipment just tends to be better designed to tighter tolerances as both the standards on inadvertent emissions and manufacturing have been tightened so it emits much less - but still not zero.

There is a lot of HF leakage from an analogue TV set up close. Not many users put their TV in a Faraday cage.