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When the site of desired operation is reached,
pull
out the
lcnob
of the
ON-OFF switch
in
the bottom of the cue
to
apply battery volbgc to the
unit. The cccieiver
now
will be
operative.
To transmit,
press
the button on
lhe microphone. releasing it again to receive.
If
the
unit
is 10
be
operated conrinuousl)· for
a
long period, occasional
checks on the transmitter filament voltage should
be
made, as the transmitter
output power falls off rapidly with small decreases ,n filament voltage. These
checks can be made most conveniently by an assistant
A change of frequency to
either the transmitter oc the
receive,
will
also have
to be nude
by
an ilSsistant unless the
optrafor
removes the unit
from his b«k.
·
When the equipment
is no
longer needed, the battery
should
be con-
set'ed by pushing in the
operating
knob of the ON-OFF switch,
and
so
opening the
battery circuit
.
SER
VICING INSTRUCTIONS
BATTERY REPLACEMENT
The
combin>.tion
"A"'
and
··n··
battery packs
should
be replaced when
the
··a--
voltage
falls
to
120 volts or when the
"'A"'
voltage
fall, to
about
2
volts, whichever occurs first.
The
··c-·
bo.ttery
mounted on top of the tr&nsmittcr-receivec chassis
should be
checked
periodically with a
high
resistance voltmeter, and
replaced
when the voltage at
its
4 .) volt
tap
drops below 3
volts.
Such replacement
should not be
necessary
more than once every
three
months or so, ~roviding
,t
is
fresh when installed, and depending considerably on the service hours
and climatic conditions to which the unit is
subjected.
TRANSMITTER SECTION
The valves in the transmitter section should be
chcc:kcd
peciodically
using
a
reliable tube checker or by replacing
them,
one
at a
time, by ones
known to be good,
and·
noting the
resulting operation
for
possible
improve-
ment. Apart from valves, little
trouble
is
J,kcly
to
be
experienced with
the
, transmitter section since all tuned circuits
c.tn be
kept adjusted quite
readily
in
the manner outlined
under "Preliminary Adj...:stmcnts··.
The contacts or the telephone-type relay
should
be
deaned periodically
using
• ··contact burnisher"
as emplored
in
the
cclephone
industry.
Should accurate neutralizing
of the
p·•
st,ge ever be considered
neces-
sary,
the following
proced
ure
should
be employed:
Connect
a resistance of from
30
to 40 ohm, between the
antenna
ter-
minal and
ground and tune the
transm,tier in the usual way into
this
dummy
load on the highest frequency. Now plug the kq cable into the key j>ek,
leaving
the
key
contact,
op,11
and connect
•
0-
120 ma, r-f metec in series
.. -,th tne dummy load
resistance.
rr
the 1ransmirier is pcoperly neutralized, the
II
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