R.flt ( Roofing Filters ) - Yaesu FT dx 1200 Operating Manual

i
nterference
Narrow-band Roofing Filters of 15 kHz, 6 kHz, 3 kHz bandwidths are provided in the first IF, right after the first mixer.
These filters provide protection
reception on a very crowded band (during a contest, etc.). Typically, the AUTO selection mode is satisfactory for most
operating situations.
Press the [ R.FLT ] button to toggle the Roofing Filter
selection.
à 3 kHz à 6 kHz à 15 kHz à AUTO .....
1
AUTO*
*1: The "AUTO" selection mode selects the optimum bandwidth of
the Roofing filter for the reception mode.
In this case, the selected bandwidth in the R.FLT column of the
Key Function Display glows green (Normally glows blue).
A :
dvice
 In the AM/FM mode, only the 15 kHz Roofing Filter
is utilized.
 As you repeatedly press the [ R.FLT ] button, the
selected Roofing Filter bandwidth will be displayed
in the R.FLT column of the Key Function Display
on the TFT display, denoting the Roofing Filter cur-
rently in use.
 Typically, this selection will be set to "AUTO."
q p :
uick oint
The "AUTO" selection of the Roofing Filter is based on
the operating mode. However, you may override the au-
tomatic selection, if band conditions warrant a different
(usually, a tighter) selection.
t :
erMinology
A "Roofing Filter," as its name implies, places a "Roof"
over the receiver IF system bandwidth. Starting at the
first mixer, the Roofing filter protects the circuitry down-
stream from strong signals, just as a roof on a house
protects the contents from rain and snow.
Page 50
r
ejection
r.Flt ( r
ooFing
for the 2nd mixer, DSP, and other circuitry that follow and can dramatically improve
)
F
ilterS
[ R.FLT ] Button
Indicates the receiver
k F
ey unction
FT 1200 O
DX
IF Roofing Filter
d
iSplAy
M
peraTing anual