Cessna 172P - Page 261

PII,OT'S OPERATING
HANDBOOK
SUPPLEMENT
10
DME
(TYPE 1e0)
IDENT
KNOB
-
F,otatiorr of
this oontrol increasoe or decreasee
the volums
of the
received
station'e
ldont
signal. An
erratic
display,
accompanled
by the
presence
of
two ldent slgnals, oan
result if
the airplane
ls
{lying
in
an area whore
two
sta,tlons using
the same
frequenoy are transmlttlng,
9, DIM-TST KNOB
-
DIM:
Controls
the
brilliance of the
readout lamp's eegxnents,
F,otate
the
control ae
desired
for
proper
laurp
illumination
in the
funotion wlndow
(The
frequenoy
window is dlmmed by
the alrcraft's
radio
light dimming
oontrol).
TST(PUSHTEST):
Thlscontrollsusedto
ut
lemps,
with
or without being
tuned
a,
readout
of
188 8 shouldbe seonwiththe
or
KNOTS
position.
The declmal
point
along wtth
188.8 will
light
in
the
MIITES mode,
When th€
oontrol ig released,
and had
the
DME
been
channeled
to a nearby
statioD, the dietauoe
to thet sta,tion
will
epp€ar.
If
the station
obanneled
was not in range,
a
"ba,r"
readoutwlll
be seon
(--'-
or
-- -).
10. MODE SELECTOR
SWITCH.
OFF:
Turns the
DME OFF,
MILES: Allows
a digital
readout to
a,ppear in the window whlch
represents
slant
range
(in
nautica,I miles)
to or from
the channeled
station.
MIN: Allows
a digital
readout
(in
minutes)
to appear in the
window
that it will
take the alrplene
to
travol the distance
to the channeled
station.
This time
is only
acourate
when
flying dirootly TO the station
and
a,fter the
ground
speed
has stabilized'
KNOTS:
Allows
a digital
r€edout
(in
knots) to aPpear
in the wlndow
tha,t
ls
ground
speed and
ie valid only afterthe
stabilization
time
(approximately
2 mlnutes)
has elapsed
when
flylng directly
TO or FROM
the ohanneled
station'
Figure 1. DME
190
Operating
Controts
(Sheet
2 of.Z)
I
30
May
1980
3