Note
QST, Jun 1981, p. 108.
QST, Aug 1981, p. 2. (290A, good image)
QST, Jan 1982, p, 100.
The major difference bewteen the A and H models is output power. The A is 10 watts and the H is 25.
CPU control with ICOM's original programs provide various operating capabilities. No-backlash dial controlled by ICOM's unique rotary encoder circuit. The band-edge detector and Endless System provides out-of-band protection. There are no variable capacitors or dial gears.
The IC-290 can accommodate FM, USB, LSB, CW coverage in the 144~146 MHz (IC-290H: 143.8~148.2MHz) frequency range.
The Memory Scan allows you to monitor five different memory channels and two VFO frequencies, and the Program Scan provides scanning between two programmed frequencies. The scanning speed is adjustable, and the auto-stop terminates scanning when a signal is received or a channel is empty, for all modes.
Two separate VFO's can be used independently either for simplex operation or for duplex operation, and any desired frequency can be split in duplex operation.
Frequencies are displayed in 5 LED digits representing 100Hz digits.
Automatic recycling restarts tuning at the top of the band, i.e., at 145.999.9MHz when the dial goes below 144.000.0MHz. Recycling changes 145.999.9MHz to 144.000.0MHz as well. Quick tuning in 1KHz steps is available, and fine tuning in 100Hz steps in the SSB and CW modes, and 5KHz steps and 1KHz steps in the FM mode.
The RF amplifier and first mixer circuits using MOS FETs, and other circuits provide excellent cross modulation and two-signal selectivity characteristics. The IC-290 has excellent sensitivity demanded especially for mobile operation, high stability, and with crystal filters having high shape factors, exceptional selectivity as well.
The transmitter uses a balanced mixer in a single conversion system, a band-pass filter and a high-performance low-pass filter. This system provides distortion-free signals with a minimum spurious radiation level.
The IC-290 has a built-in noise blanker, CW break-in, CW monitor, and APC.
Specifications
– Numbers of semiconductors
Transistor: 61
FET: 6
IC: 28
Diode: 134 (IC-290H: 135)
– Frequency coverage:
144.0 MHz~146.0 MHz
IC-290H: 143.8~148.2 MHz
– Frequency resolution: SSB 100Hz steps, FM 5KHz steps
1KHz steps with 1KHz STEPS button depressed
– Frequency control: Microcomputer based 100Hz step Digital PLL synthesizer. Independent Dual VFO Capability
– Frequency readout: 5 digit LED 100Hz readout
– Frequency stability: Within ±1.5KHz
– Memory channels: 5 channels with any inband frequency programmable
– Usable conditions: Temperature: -10°C~60°C (14°F ~ 140°F)
– Operational time: Continuous
– Antenna impedance: 50 ohms unbalanced
– Output power:
SSB: High 25 (10) W (PEP), Low 1W (PEP)
CW: High 25 (10) W, Low 1W
FM: High 25 (10) W, Low 1W
– Emission mode: USB, LSB, CW, FM
– Modulation system:
SSB: Balanced modulation
FM: Variable reactance frequency modulation
Max. frequency deviation:** ±5KHz
– Spurious emission: More than 60dB below peak power output
– Carrier Suppression: More than 40dB below peak power output
– Unwanted Sideband: More than 40dB down at 1000Hz AF input
– Microphone: 1.3K ohm dynamic microphone with built-in preamplifier and push-to-talk switch.
– Operating mode: Simplex, Duplex (Any in-band 100KHz steps frequency separation programmable)
– Tone Burst: 1750Hz ±0.1Hz (IC-290H: Not installed)
– Receiving system:
SSB, CW: Single conversion superheterodyne
FM: Double conversion superheterodyne
Receiving mode: SSB (A3J, USB/LSB), CW (A1), FM (F3)
– Intermediate frequency:
SSB, CW: 10.75MHz
FM: 10.75MHz, 455KHz
– Sensitivity:
SSB, CW: Less than 0.5 uV for 10dB S+N/N
FM: More than 30dB S+N+D/N+D at 1 uV; Less than 0.6 uV for 20dB Noise quieting
– Squelch sensitivity: Less than 0.4 uV
– Spurious response rejection ratio: More than 60dB
– Selectivity:
SSB, CW: More than ±1.2KHz at -6dB point; Less than ±2.4KHz at -60dB point
FM: More than ±7.5KHz at -6dB point; Less than ±15KHz at -60dB point
– Audio output power: More than 2W
– Audio output impedance: 4~8 ohms
Power supply requirement: 13.8 VDC, 6A Max.
Current drain (at 13.8 VDC):
Transmitting:
SSB (PEP 25W): Approx. 4.8A
CW, FM (25W): Approx. 5.0A
FM (1W): Approx. 1.6A
Receiving:
At max audio output: Approx. 0.9A
Squelched: Approx. 0.7A
