Tube Freq Output power Gain Eff Voltage Size Weight 2xGU74b/4cx800a 144 MHz > 2500 Watts 19 - 20 dB 74% linear mode 220-240 Volt 19 x 17 x 11 Inch 45 Kg Heater and High Voltage both "soft" start High Voltage delay timer:  HV cannot turn on before the tube is ready Cannot apply drive without HV: PA kept in STDBY (No operation is possible without HV) HV plate line is fuse protected The HV transformer protected by magnet circuit breaker (overcurrent breaker) Control and screen grids are overcurrent protected (trip circuit) Blower delay timer:  Blowers run after PA is off for better cooldown Built-in coax relay sequencer:  Separate exciter & tower relay/preamp box outputs Coax transfer relays