MJ8503 Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 800 V
• Collector-Base Voltage, max: 1400 V
• Emitter-Base Voltage, max: 8 V
• Collector Current − Continuous, max: 5 A
• Collector Dissipation: 150 W
• DC Current Gain (h_fe): 8
• Operating and Storage Junction Temperature Range: -65 to +200 °C
• Package: TO-3

Here is an image showing the pin diagram of this transistor.You can replace the MJ8503 with the MJ8505.