Q: You mentioned the new 48kHz DSP (vs. 36kHz). Please explain why this is a large improvement. I'd like to know about some of the other important items as well.
A1: The 48kHz DSP is a big step up, because it will execute the DSP algorithm 25% faster than the 36kHz design. Thus, all processes in the algorithm will execute faster and more cleanly. The benefits to the user will be such items as:
Improved stop-band attenuation and shape-factors in IF filters
Greater rejection and improved shape-factor in the tuneable notch
Faster attack, better rejection and ability to suppress a greater number of tones in the auto-notch
More effective NR and NB
Faster attack and wider adjustment range in the AGC
Improved linearity and S/N in modulation and demodulation processes
Faster attack and improved linearity in the compression algorithm
Improved response time and narrower minimum RBW in the spectrum scope (now also implemented in DSP)
Sufficient extra "horsepower" for addition of new features
I believe that future DSP-based Icom receivers and transceivers will incorporate 48kHz DSP. One might wonder whether the ADC used in the new 48 kHz IF-DSP system will have slightly more dynamic range than the ADC's used currently in the IC-7800 and IC-756Pro3. This ADC will have to support a 96 kHz sampling rate.
A2: The aspects of the R9500 which I found most striking are as follows:
The 48kHz DSP
The improved spectrum scope, with adjustable RBW (min. 200Hz, useful for IMD analysis)
The dual DSP-based noise blanker
The adoption of the IC-7000's dual tuneable notch
The relay-switched front-end BPF (although I would have expected no less in a receiver of this calibre)
The ability to adjust centre frequency as well as BW and shape factors in the IF filters
Synchronous AM and APCO P25 reception capability
The enormous frequency coverage
The very attractive new cabinetry and front-panel styling (not unlike that of R&S)
Copyright © 2006, A. Farson VA7OJ/AB4OJ. Images courtesy Icom Inc.
Last updated: 09/25/2019