MFJ MFJ-784B, Instruction Manual, Page: 55 / 74

MFJ-784B Instruction Manual
Filter Description 5-3
Band-stop Filter
Use: Rejecting broad or variable frequency signals between 1400-2200 Hz.
Removes medium to wide frequency width.
When the low reject filter,
the Tunable Filters left knob, is adjusted to a
frequency higher than the high reject filter, the Tunable Filters right knob, the
filter removes all frequencies between the two filter settings and passes all
frequencies outside the settings of the two filters. This special filter is called a
band-stop or band-reject filter. A band-stop filter makes a "hole" in the middle
of the frequency range and passes everything on either side of the "hole."
For example: If the low reject filter is adjusted to 2200 Hz and the high
reject filter is adjusted to 1600 Hz, all frequencies between
1600 Hz and 2200 Hz will be removed. This creates a hole
with a 600 Hz bandwidth.
Typical Band-stop Filter Response
Frequency (Hz)
dB
-70
-60
-50
-40
-30
-20
-10
0
0 500 1000 1500 2000 2500 3000 3500 4000