Interesting how much things change in just a few years. The interest in changing ceramic IF filters in the 996XT was started by Boatanchor, who discovered that a slightly narrower bandpass filter would improve NBFM and AM reception signal/noise.
Mu-Rata has discontinued making 450 KHz bandpass filters and their ceramic filter line is almost entirely limited to 10.7 MHz. This situation suggests that the newer scanners are using DSP filters for the IF. If that is so, the bandpass could easily be changed on the fly to correspond to the signal being received. I guess this approach is now used in all better quality ham receivers also. Anyone familiar with the general design of the 996P2?
I hear a lot of complaining about poor audio during digital decoding. This is typical of the electronics industry to sell a technology based on some irrelevant, imaginary benefit. Remember that fantastic audio quality was the reason for cell phones to transition to digital? Not! The real reason for the change was to fit more signals into a small bandwidth - which is a valid design goal. The goal in both cases is not fantastic audio quality. This is communications radio, not surround sound. Whether it is basically CDMA or TDMA, or some other algorithm, the basic idea is to accommodate more traffic, to implement proprietary channel use, or to provide space for some nearly useless data transmissions, and not to produce recording studio audio. For communications use (i.e. weak signal communications ability), FM is still more reliable and effective. That's the way it is.
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