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Icom IC-781
Specifications

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Discontinued Amateur Base Transceivers 

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IC-781 Specifications

General
  • Frequency Coverage:
    • Receive:
      • 0.1 ~ 30.0 MHz
      • guaranteed range 500 kHz ~ 30 MHz
    • Transmit:
      • 160-m band 1.8 ~ 2.0 MHz
      • 80-m band 3.5 ~ 4.0 MHz
      • 40-m band 7.0 ~ 7.3 MHz
      • 30-m band 10.1 ~ 10.15 MHz
      • 20-m band 14.0 ~ 14.35 MHz
      • 17-m band 18.068 ~ 18.168 MHz
      • 15-m band 21.0 ~ 21.45 MHz
      • 12-m band 24.89 ~ 24.99 MHz
      • 10-m band 28.0 ~ 29.7 MHz
  • Modes: A3J (SSB),A1 (CW),F3 (FM), F1 (RTTY), A3 (AM)
  • Frequency step: 10 Hz (with [TS] OFF); 1 Hz (with [TS] ON)
  • Antenna impedance (with [TUNER] OFF): 50 ohms (unbalanced)
  • Power Supply Requirement: 100 ~ 120 V AC (U.S.A. version).
  • Power consumption:
    • Receiving maximum. audio: 150 VA; standby: 140 VA
    • Transmitting maximum.: 760 VA; minimum: 325 VA
  • Usable Temperature Range: -10C to +60C; +14F to +140F
  • Frequency stability: 15 Hz (-10C to +60C; +14F to +140F)
  • Dimensions: 425(W) x 149(H) x 411(D) mm, 16.7(W) x 5.9(H) x 16.2(D) in
  • Weight: 23 kg; 50.7 lb.

 

Transmitter
  • Maximum output power:
    • SSB: 150 W PEP
    • CW, RTTY, FM: 150 W
    • AM: 75 W
  • Modulation system:
    • SSB: balanced modulation
    • FM, RTTY: reactance frequency modulation
    • AM: low level modulation
  • Maximum frequency deviation: 5 kHz
  • RTTY shift width: 170 Hz, 425 Hz, 850 Hz selectable
  • Spurious emissions: Less than -60 dB
  • Carrier suppression: Less than -40 dB
  • Unwanted sideband: Less than -55 dB (with 1 kHz modulation)
  • Microphone impedance: 600 ohms

 

Receiver
  • Receive system:
    • SSB, CW, AM, RTTY: Quadruple-conversion superheterodyne
    • FM: Triple-conversion superheterodyne
  • Intermediate frequencies:
    Mode 1st 2nd 3rd 4th
    SSB 46.5115 MHz 9.0115 MHz 455 kHz 10.6950 KHz
    CW, RTTY 46.5106 MHz 9.0106 MHz 455 kHz 10.6950 KHz
    AM 46.5100 MHz 9.0100 MHz 455 kHz 10.6950 MHz
    FM 46.5100 MHz 9.0100 MHz 455 kHz -
     
  • Sensitivity (preamp ON):
    • SSB, CW, RTTY (for 10 dB S/N):
      • 0.1 ~ 0.5 MHz Less than 0.5 V
      • 0.5 ~ 1.8 MHz Less than 1.0 V
      • 1.8 ~ 30 MHz Less than 0.16 V
    • AM (for 10 dB S/N):
      • 0.1 ~ 0.5 MHz Less than 3.2 V
      • 0.5 ~ 1.8 MHz Less than 6.3 V
      • 1.8 ~ 30.0 MHz Less than 1.0 V
    • FM (for 12 dB SINAD):
      • 28 ~ 30.0 MHz Less than 0.23 V
  • FM squelch sensitivity: 28 ~ 30 MHz Less than 0.23 V
  • Selectivity:
    • SSB, CW-W, RTTY-W, AM-N: More than 2.4 kHz/-6 dB ; Less than 3.8 kHz/-60 dB
    • CW-N, RTTY-N (with [CW250Hz] OFF): More than 500 kHz/-6 dB; Less than 1 kHz/-60 dB
    • CW-N, RTTY-N (with [CW250Hz] ON): More than 250 kHz/-6 dB; Less than 800 kHz/-60 dB
    • AM-W: More than 6.0 kHz/-6 dB; Less than 15.0 kHz/-60 dB
    • FM: More than 15.0 kHz/-6 dB; Less than 30.0 kHz/-50 dB
  • Spurious and image rejection ratio:
    • Image: Less than -80 dB
    • IF: Less than -70 dB
  • Audio output: More than 2.6 W with an 8 ohm load at 10% distortion
  • Notch filter attenuation: More than 45 dB
  • RIT variable range: 9.99 kHz
  • Specifications are subject to change without notice or obligation.

 

Antenna Tuner
  • Output matching range: 16.7 ~150 ohms unbalanced
  • Minimum input power: 15 W
  • Auto tuning accuracy: VSWR less than 1.2:1
  • Insertion loss: Less than 0.5 dB (after tuning)

 

CRT Display
  • Output level:
  • Composite video signal: 1 Vp-p
  • Video components: 0.7 Vp-p positive
  • Synchronous components: 0.3 Vp-p negative
  • Output impedance: 75 ohms
  • Horizontal frequency: 15.75 kHz
  • Vertical frequency: 60 Hz


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