The IC-756Pro/Pro II has a real-time Spectrum Scope module (actually a mini-spectrum analyser with 1 kHz RBW @ -6dB) which is completely independent of the main receiver. The IC-746Pro "borrows" the main receiver to perform a band sweep for the spectrum-scope display (non-real-time). The receiver is muted during the sweep.
The IC-756Pro/Pro II has two independent physical 1st local oscillators (synthesisers), allowing Dual Watch operation (simultaneous reception on two frequencies in the same band and mode). The IC-746Pro lacks this capability.
The IC-756Pro II has a stronger RF front end than the IC-746Pro (IC-7400) or the IC-756Pro. It is interesting to note that the 7400 has two filters in cascade with 2 transistors in the 1st mixer, whilst the 756Pro II has only one filter and 4 transistors in the 1st mixer.
The IC-756Pro and Pro II use the ADI SHARC DSP; the IC-746Pro employs the TI DSP. The DSP performance in the two radios is similar, although the 746Pro's ADC's are a little noisier. The IC-746Pro's slightly superior IF-filter performance suggests DSP improvements.
The IC-746Pro has 2-metre capability; the IC-756Pro/Pro II/Pro III do not.
The IC-746Pro has a monochrome dot-matrix type LCD display, whilst the IC-756Pro and Pro II have a full-colour TFT display.
The IC-756PROII has a built in voice keyer, whereas the IC-746Pro does not.
The IC-756PROII has a separate receive-only (RX ANT) antenna socket; the IC-746Pro does not.
Voice-activated squelch, receive tone controls and a graphical SWR/frequency plot are offered on the IC-746Pro, but not on the IC-756Pro or IC-756Pro II.
The IC-746Pro CW keying sidebands fall off a little more rapidly than those of the IC-756Pro II.
Copyright © 2003 A. Farson VA7OJ/AB4OJ. All rights reserved. Last updated 11/27/15