Operating instructions
:irr.
,,uter
ring
of the
MANUAL-PRE-
SF-T
TU\ING
control.
(2)
if the
clesired
frequency
has been
pre-
set.
pttlÌ
out
the
fine-tuning
control,
lift the
cam arm, and
rotate
the
MAN-
UAL-PRESET
TUNING CONTROL
r"rntil the
arro'Ltted
hole is over
the de-
sired
numbered
detent.
i.
Adjust
the
ANT.
TRIMMER
for
maximum
output
signal.
g.
Keep the
R.F. GAIN
control
low
for strong
signals
to
prevent
overloading;
the
volume
can
be
regulated
by
the
R.F. GAIN
control.
23.
Net
Operotion
o.
Repeat
the
procedure outlined
in
para-
graph
2l or
22, using
the
frequency
of the
net
control
station.
b.
Set
a
numbered
detent
(if
available
and
not
already
set)
to this
frequency
channel.
c.
Set
the
PHN.-C.W.-NET-CAL.
switch
to
the
NET
position.
d.
Without
disturbing
the
receiver,
tune
the
ercí,ter
of the
local transmitter
to
the
net-con-
trol-station
frequency
by tuning
(the
exciter)
for a
zero-beat
indication
on
the
receiver.
e.
Set
the
PH\-.-C.\\r.-NET-CAL.
switch to
the
PHN. or C.\\'.
qrosition,
as
required.
l.
Complete
the
tuning
of the transmitter.
24.
Callbrotion
To calibrate
the
receivef.
Ìrerform
the
follow-
ing steps
:
o.
Turn the
PO\trrER
su'itch
to
ON.
b. Adjust
the
filament
voltage
(par.
15ci).
c.
Turn PHN.-C.W.-NET-CAL.
to
CAL.
d.
Short
the antenna
with the
shorting
srvitch
and check
the
calibration
of the
I'IANUAL-
PRESET
TUNING
control over
the
complete
range of
tuning
for all
four bands.
A beat
note
should
be
heard at every
integral
multiple
of
200 kc. If
necessary,
tune
ANT.
TRIMMER
control
for maximum
beat
signal.
When
the
beat
note does
not occur
at
integral multiples
of
200
kc, it
is necessary
to realine the
receiver.
25. Stopping
Procedure
a.
Turn the POWER
switch to OFF.
b. Turn
the
MANUAL-PRESET
TUNING
control
to the
l-f
(low-frequency)
end of the
tuning
range of
any band.
This
protects
tuning-
capacitor
plates.
Section
lV. OPERATION
IJNDER UNUSUAL
CONDITIONS
Note. Radio
Receiving
Set AN/GRR-5
is rvaterploof
and
should
be
kept
in its cabinet
at all
tiines
except
for
maintenance
purposes. Tighten cap
of
SPARE
FUSES
compartment
"vhen
set
is not in
use.
26.
Generol
The operation
of
Radio
Receiving
Set
AN/
GRR-5
may be
difficult
in regions
of extreme
cold,
heat,
humidity,
sand,
mud'
snow'
etc.
In
lrirragraphs
27,
28, and
29, instructions
are
given
on
procedures for
minimizing
the effect
of these
unusual
operating
conditions.
27. Operotion
in Arctic
Climotes
Subzelo
temperatures
and
climatic
conditions
..,,ciAte(l
rvith cold
'lveather
may
affect
the effi-
'.-,1i
,1rei'ation
of the
equipment.
Instructions
ì
lrlecaLrtious
for operation
under
such
ad-
.
r'-,. rrìn(litiotts
follow:
o. Handle
the equipment
carefully.
b. Keep
the equipment
warm and
dry.
If the
set
is not in a
heated
inclosure,
construct
an
insulated
box
for the
set.
Keep the
filaments
of
the
vacuum
tubes
lighted
constantly,
unless
this
overtaxes
the
power
suPPlY.
c.
Wear
a
knitted
woolen
cap
over the
ear-
phones
when
operating
in the
open air
with
headsets
that
do
not have
rubber
earpieces.
Frequently,
when
headsets
without
rubber
ear-
pieces
are
worn,
the
edges
of
the ears
may
freeze
without
the
operator
being
conscious
of
this
condition.
Never
flex rubber
earcaps'
since
this
action
may render
them useless.
If water
gets
into
the
receivers,
or
if moisture
condenses
within
them,
it may
freeze
and
impede
the
actuation
of the
diaphragm.
When
this
hap-
pens,
remove
the
bakelite
cap
and
remove
the
ice
and
moisture.
AGO
B13A