Increase Power Output The stock IRF520 can be swapped out for IRFZ24N, and peak power will increase by about 20 watts.  Please check to see If you radio can take the modification.
 
4 in each package
 
GENERAL DESCRIPTION QUICK REFERENCE DATA N-channel enhancement mode SYMBOL PARAMETER MAX. UNIT standard level field-effect power transistor in a plastic envelope using VDS Drain-source voltage 55 V ’trench’ technology. The device ID Drain current (DC) 17 A features very low on-state resistance Ptot Total power dissipation 45 W and has integral zener diodes giving Tj Junction temperature 175 ˚C ESD protection up to 2kV. It is RDS(ON) Drain-source on-state 70 mΩ intended for use in switched mode resistance VGS = 10 V power supplies and general purpose switching applications.