Note
The Icom IC-735 is a complete HF all-band transceiver and general coverage receiver. As a notable piece of late 20th-century solid-state gear, it packs a significant amount of advanced technology for its time into a compact package, making it highly suitable for mobile, portable, or space-constrained base station setups.
Features
– Transmitter: It covers all amateur HF frequencies from 1.8MHz to 30MHz, which includes the 10MHz, 18MHz, and 24MHz WARC bands.
– Receiver: Tunes continuously from 100kHz to 30MHz.
– Operating Modes: It supports SSB, CW, AM, and FM operation.
Power: Roughly 100 watts of output power. Specifically, it handles 200 watts PEP input for SSB, 200 watts input for CW and FM, and 40 watts of output for AM.
– Output power is continuously adjustable from 10 watts to its maximum.
The receiver boasts a 105dB dynamic range, utilizing a 70.4515MHz first IF circuit with two high-quality crystal filters to virtually eliminate spurious responses.
DFM System: It incorporates ICOM's Direct Feed Mixer (DFM) system. This feeds incoming signals directly into a high-level first mixer, resulting in a higher spurious response rejection ratio, wider dynamic range, and better sensitivity.
Signal Management: The unit features a Passband Tuning (PBT) system for continuous center frequency adjustment of the IF passband, alongside a sharp IF notch filter to cut out strong interference.
Amps/Attenuators: A 10dB preamplifier and a 20dB attenuator are included as standard equipment.
Dual VFOs & Memory: It features two VFOs (A and B) and 12 programmable memory channels that store both frequency and mode. The internal CPU is backed up by a lithium battery that maintains the memory for up to five years.
Scanning: It supports multiple scanning features, including Memory Scan, Programmed Scan (between two programmed frequencies), and Mode Selective Scan.
Specifications
– Ham Bands: 1.8–2.0MHz, 3.4–4.1MHz, 6.9–7.5MHz, 9.9–10.5MHz, 13.9–14.5MHz, 17.9–18.5MHz, 20.9–21.5MHz, 24.4–25.1MHz, and 27.9–30.0MHz.
– General Coverage Receiver: Continuous from 0.1MHz to 30.0MHz.
– Emission Modes: SSB (A3J/J3E), CW (A1/A1A), AM (A3/A3E), and FM (F3/F3E).
– Frequency Control: CPU-based 10Hz step digital PLL synthesizer.
– Frequency Stability: Less than ±200Hz from 1 to 60 minutes after power-on; less than ±30Hz after 1 hour at 25°C.
– Antenna Impedance: 50 ohms unbalanced.
Transmitter
– RF Output Power: SSB/CW/FM: 200 watts PEP input (approximately 100 watts output); AM: 40 watts output.
– Output power is continuously adjustable from 10 watts to maximum.
– Spurious Output: More than 50dB below peak power output.
– Carrier Suppression: More than 40dB below peak power output.
– Unwanted Sideband: More than 50dB down at 1000Hz AF input.
– Microphone Impedance: 600 ohm electret condenser.
Receiver
– Receive System: Triple conversion superheterodyne.
– Intermediate Frequencies:
1st: 70.4515MHz (SSB, AM, FM) or 70.4506MHz (CW).
2nd: 9.0115MHz (SSB, AM, FM) or 9.0106MHz (CW).
3rd: 455kHz (all modes).
– Sensitivity (1.6–30MHz with Preamp ON):
SSB/CW: Less than 0.15µV for 10dB S/N
AM: Less than 1.0µV for 10dB S/N
FM: Less than 0.5µV for 12dB SINAD.
– Selectivity:
SSB/CW: 2.3kHz at -6dB; 4.0kHz at -60dB.
AM: 6.0kHz at -6dB; 18kHz at -50dB.
FM: 15kHz at -6dB; 30kHz at -60dB.
– Spurious and Image Rejection: More than 80dB.
– Audio Output: More than 3 watts at 10% distortion with an 8 ohm load
Power Supply Requirement: 13.8V DC ±15% (negative ground).
Current Drain (at 13.8V DC):
Transmit: Approximately 20A at 200W input.
Receive: Approximately 1.5A at maximum audio; 1.2A when squelched.
