2m GU-78b Amplifier
by LZ2US
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Tube:  GU78B / 4CX2500
Freq:  144 MHz
Power output > 4 kw
Power gain:  20-21 dB

Eff.  70 %  linear mode
220-240 volts
Size:  19x17x11 inches
Weight:  54Kg / 25Kg w/o HV supply
  • 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 (depends on the order - contact LZ2US to discuss)
  • Available also as RF Deck only; complete except for HV supply:  Requires 3KV @ 2.2A
  • Overall View

    Bottom View

    Top View

    Rear Panel & Bottom

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