That's interesting - I heard that the 7600Grs sync detc injects some
noise and that it doesn't lock onto weak signals very well. As with
all filters, the audio quality suffers, even cheap/bad PLL circuitry
injects some noise. The S350 is s typical example, where the narrow /
wide and low-pass filters have little effect and only muffle the audio.
I tried the S350 and it was the cheapist piece of crap radio, so for
AM DXing I just bought a $25 PLL RS radio that performs, as well as,
the S350. Too many radios are over-hyped - hell, my car radio received
everything the S350 could. The CCradio and SRII are over-hyped, as
well...