Searched for it on jaycar, and i got a result! TIP41C NPN Transistor
Silicon TypeType Mat Case Diss Vcb Ic Hfe Hfe @25C BiasTIP41C NPN TO-220 65W 100V 6A 30 3A
Seems ok to me, is that the one you are talking about?
Just had a look on the site with the circuit diagram, here is what it has to meet up to:
Bipolar NPN transistor : BD243C
Casing : TO220
Max. collector current : 6 Amperes
Max. total power : 65 Watts, while case is at 25 degrees Celsius
Transition frequency : 3 MHz
hFE (current gain) : 30 at 300mA (minimum value