IC-746 PRO

The ICOM IC-746 HF/VHF rig was first released in 1998, become one of the best value transceivers in the marketplace. The IC-746PRO upgraded radio, with a new DSP system, was released three years later. Following on the success "746" the "746 Pro" covers 160-10 meters plus 6 and 2 meters all mode, 100 Watts of output is available on all bands. The new Pro version features 32 bit floating point Digital Signal Processor and 24-bit ADC/DAC. There are no more optional 9 MHz or 455 kHz IF filters as the digital circuit allows your to select 51 filter bandwidths. There is even a built-in Baudot RTTY demodulator. The IC-7400 is the "746 Pro" version approved for the European market, similar in specifications but with VHF receive frequency coverage limited to 144-146 MHz.

IC-746 PRO description :

Icom has taken the DSP technology introduced in the IC-756PRO series, and created a whole new radio category. Covering all HF bands as well as 50 MHz and 144 MHz, the transceiver also includes a general coverage receiver from 0.03-60 MHz and 108-174 MHz with full IF DSP capability. The IC-746PRO incorporates the 32-bit DSP features to create some of the most flexible signal enhancing, and interference reduction ever offered in this type of radio. Starting with the 32-bit DSP processor and 24-bit ADC/DAC, Icom enables the ham radio operator to create the listening environment that best suites the current band and operating conditions. All Mode Digital Modulation and Demodulation: For signal purity and clarity, an all mode digital PSN (Phase Shift Network) system has been incorporated into the DSP system. For transmit, this greatly reduces the intermodulation distortion, producing the highest quality transmit audio. While the PSN separates the signal from noise by phasing out noise and other unwanted signals. IF Filter Shapes: You will never have to purchase optional filters, with over 51 different filter widths, just dial in the width you want. Then select whether you want a sharp or soft filter shape for SSB and CW modes, see figure. For the Digital operators, your digital filters are separate from the SSB filters.

ICOM IC-746PRO SSB soft (left) and sharp (right) filter

ICOM IC-746PRO CW soft (left) and sharp (right) filter

Above, example of 2.4kHz SSB and 500Hz CW filter shape. Passband width range 50-3600 Hz for SSB mode, 50 to 500 Hz with 50Hz step and 600 to 3600 Hz with 100Hz step. By manipulating the incoming signal, the DSP is able to reduce various types of noise (Digital Noise Reduction) and enhances the receive signal components. Providing an outstanding signal to noise ratio to give clean, clear audio.

The internal antenna tuner matches the HF and 50 MHz bands automatically. After operating on a band for the first time, the tuner memorizes the selected antenna and preset point providing for very high speed tuning. Two antenna connectors for HF and 50 MHz bands and one for 144 MHz band is equipped on the IC-746PRO.

IC-746 PRO digital twin PBT and notch filter :

Tailor your IF passband with the Twin PBT by shifting the upper and lower IF passbands. Depending on the use of the concentric knobs, you can either narrow the IF passband, or shift the entire passband to eliminate interfering signals. Interference management is not a problem with the manual Notch filter. With it's incredible 70 dB attenuation, the manual notch can eliminate a wide variety of single-tone QRM. The automatic Notch Filter can on the other hand track two or more interfering signals like heterodynes.

IC-746 PRO AGC loop management :

Another first in this class of transceiver, the IC-746PRO incorporates a multiple Automatic Gain Control loop management system, which uses the DSP filtering to remove unwanted signals from the AGC control. This means, if an unwanted signal is removed using the DSP, the AGC will not be affected. Also, the Automatic Gain Control is independently controllable for mode and the time settings. (Off, 0.1-6.0 or 8.0 sec.).

ICOM IC-746PRO AGC loop

IC-746 PRO CW/RTTY functions :

Ample CW functions as electronic keyer, variable dot/dash ratio (2.8:1 to 4.5:1) and key speed (6-60 WPM), paddle polarity, bug key etc. CW pitch is adjustable (300 to 900 Hz). Full break-in capability. Double key jacks, one each for front and rear panel. 4 channel memory keyer stores up to 50 characters with serial contest number auto-counter, morse cut-number and auto repeat function. The built-in RTTY demodulator and decoder reads baudot RTTY signals on the screen without turning on your PC or other gear. The RTTY tuning indicator helps critical tuning. The Twin Peak filter removes interfering QRM giving you a more accurate decoded message.

The Microphone Equalizer will change your RST from "59" to "59 and Great Audio". Adjust your audio for Bass and Treble characteristics to total 121 levels for all voice operation. The transmit filter width in SSB mode is selectable from 2.8, 2.4 or 2.2 kHz. The receive tone control is also an equalizer for the received audio. As with the transmit audio, select the amount of Bass and Treble you need for the audio clarity you want.

ICOM IC-746PRO Speech Compression

Digital RF Speech Compression gives you all you need without fuss and noise. Great for breaking through QRM.

IC-746 PRO continuous duty at 100 Watt :

The 2SC2694 bipolar transistor are used to provide a clean 100 Watt of output power for SSB, CW, RTTY and FM modes (40 Watt in AM). The die-case aluminum chassis and the variable speed cooling fan enables the IC-746PRO to transmit full power all the time, the perfect companion for digital mode QSOs.

IC-746 PRO other features :

• 1Hz tuning and indication
• Triple band stacking register
• 2 types of preamplifier, regular and high gain, for HF and 50 MHz bands
• 1 preamplifier for 144 MHz band
• 20dB RF attenuator
• Level adjustable noise blanker, in 101 steps
• BPF function below 500 Hz band width in SSB mode
• 1/4 speed dial tuning function for SSB-data, CW and RTTY modes
• 108 selectable DTCS and 50 selectable CTCSS with encoder/decoder
• 1750Hz tone encoder
• Up to 10 memo-pads temporarily store frequencies and modes
• Quick split function with split lock function
• RIT and Delta-TX (XIT)
• Band edge beep
• CI-V capability for PC control
• VOX
• IF transmit audio monitor in SSB mode, AF transmit audio monitor for the other modes
• 102 memory channels
• 9600bps data terminal

By installing the CR-338, the total frequency stability of the transceiver will be improved. Remove the bottom covers, then remove the 4 screws from the shield cover of the RF unit, and disconnect P2 (Chassis) from J761 (Main), then lift up the shield cover as shown.

ICOM IC-746PRO optional high-stability crystal unit (CR-338) installation

Remove the 8 screws from the RF unit, disconnect J1, J121 and J151, then remove the RF unit. Now remove the supplied internal crystal and replace with the CR-338. Return the RF unit, J1, J121 and J151 to their original positions. Connect a frequency counter to the J262, 2LO IN, then adjust the reference frequency to be 64.00000 MHz with the L1901 on the RF unit. Return the J262, shield cover, P2 and bottom covers to their original positions.

IC-746 PRO options :

ICOM IC-746PRO options

IC-746 PRO price

We have collected for your convenience the ICOM IC746-PRO sale price (Euro) and its trend over time. Useful to guarantee a cheaper purchase of this radio and to put it for sale in the second-hand market. Of course offers, accessories, warranty terms and conditions can lead to different figures.

Price	Date	Condition
EUR 575.00 (600USD)	2022-jun	Second Hand In pretty good condition. Comes with HM-36 microphone, power cord, manual
EUR 728.90 (819USD)	2016-may	Second Hand Comes with HM-36 hand mic, DC power cord, original owner's manual, box