I made a few tests yesterday. A non-jamming SU27 could be picked up a 100ish NM in RWS. A jamming SU27 was reduced in the 80ish NM range. Small effect, but not shown on the radar.
In the other hand, I found FC3 radar the be somewhat underpowered. Using the jammer, they could lock at 21n , and without jamming lock in the 32ish NM range. Seems suspicious and probably not realistic.