Spectra 72Mhz no range

[Abdul]

Got a used spectra 72Mhz Module from a member here.
Tested with few Rxs, no range.
Suspect the Rf power transistor giving problem.
Transistor get very hot when switched on with antenna extended.

Part number C4910.
Can't find replacement part at SL tower.

Does anyone know where to get the part ?
Any substitute?

Thanks