FM IF Filter
With these ultra narrow filters, RDS reception is impossible, and strongly modulated
stations are distorted and hard to understand. Therefor, the selectivity is fantastic.
These very narrow filters allow RDS reception only on very strong stations; strongly modulated
stations can be slightly distorted, but the selectivity is very good. If you don't need RDS, these
filters might be the best compromise between selectivity and listening pleasure
82kHz (= 80kHz Wide)
Those filters are quite rare, since they are actually "bad" 80kHz filters, which are just
too wide. Their advantage is, that RDS can be decoded in most cases, while the selectivity is
still very good. If you can get hold of them, don't hesitate - especially when you want to
decode the RDS signals
These filters are the smallest "regularily" available IF filters. The offer a quite good
sensitivity and allow perfect RDS decoding. If you perform serious FM DXing, you should use
filters not wider than these; only for HiFi puristy, they might be too small.
Better HiFi receivers sometimes use 150kHz filters. They have hardly any impact
on the sound and offer a fair sensitivity, but are not really suitable for DXers.
These filters are standard equipemt in many radios and tuners. They are much to wide for DXing.