Quick and dirty fix, just replace the following section. (This radar could use MoonJumper's avionics expertise.) The DetectSettings section of the aircraft data INI needs to be updated as well, so the AI will not be saddles with the old settings.
Anyway, assuming this is the Smerch-A1 radar, it should be able to detect targets at ~100km and track at ~50km with a massive amount of power. This particular radar was compromised when Belinko defected, but was still sold in export versions of the Foxbat.
[AvionicsData]
AvailableModes=SEARCH,ACQUISITION,TRACK,BORESIGHT
RangeUnit=KM
RangeSetting[1]=25
RangeSetting[2]=50
RangeSetting[3]=100
RadarPosition=0.0,4.0,0.0
MaxElevationAngle=17.66
MinElevationAngle=-17.66
MaxAzimuthAngle=56
MinAltitude=800.0
MinReturn=0.05
SearchRangeSetting=3
ScanPattern[1].BarElevation[1]=4.0
ScanPattern[1].BarElevation[2]=0.0
ScanPattern[1].BarElevation[3]=-4.0
ScanPattern[1].ScanRate=70
ScanPattern[1].ScanBeamAngle=6.0
ScanPattern[1].ScanArc=56
SearchRange=100
SearchStrength=150
SearchTargetTime=1.0
AcquisitionSymbolSpeed=1.5
AcquisitionTime=1.5
LostAquisitionTime=1.0
TrackRangeSetting=2
TrackCapabilities=
TrackRange=25
TrackStrength=120
TrackMemroyTime=5.0
BoresightRangeSetting=1
BoresightElevation=1.5
BoresightAzimuth=0.0
BoresightBeamAngle=12