Swann 400 - Transmitter Tuning Procedure

I MODEL
4OO
TRANSCEIVER
C. Ope
ration
{Cont)
4. Your Swan
400
will automatic ally
transmit on
exactly the same {!e-
quency
as
the one to which
you are
Iistening. There
is no adjustment
Jor rnaking them
the sarne, since,
by using
the 6alne oscillato!
for
both send
and receive, it
happens
automatically.
If separation
of re-
ceive and
transmit frequency
con-
trol is
desired, the
Model
22
dual
VFO adaptor
rnay
be installed
in
the
VFO
socket
on back
of the 400,
and a
pair
of 410's
or 4068's
may
then be
p)ugged into
lhe adaptor'
CALIBRATE
To calibrate
the Model 410
Frequency
Control
Unit dial,
tollow
these four
steps:
l.
Rotate the
function
switch to CAL.
Z, Rotate
th€
Kilocycles
dial to the
100
kc increment
neare6t the
d€
si red operating
frequency.
3,
An audio
beat note
will be heard
in the
6peaker.
4,
Adjust
the
Dial Set knob
for zero
TRANSMITTER
TUNING
Tuning
of the transmitter
is
not com-
plicated,
providing the lew
simPle steps
are followed
in the co!rect
order.
Do
not attempt
ini.tial
tuneup without
first
performing
the
ptocedures for Receive
operation
described
above.
The louow-
ing
procedures
assurne
that
the
unit has
been
checked
out in Receive
Position,
and
that the
powe! suPPIy
and Frequency
Codtrol
Unit are adjrsted
and
oPerating
properly.
t. Rotate
the Fonction
S]vitch
to
TRANSMIT,
read
the cathode
current
on
the front
Pane1
meter.
l4
Ouickly
rotate the
CAR
BAL con-
trol
on the lront
Panel
until
the
mete!
reads
rninimurn
cathode
Next, adjust
the PA
Bias control
on
the rear
ol the
chassis until
the
mete!
reads 50 !na.
3.
4. If thi€
is the
first time the
trans-
ceiver
is being
tuned on this
band,
set
the PA LOAD
switch
to
Position
l. Afte!
experience
ir tuning
uP,
the control
rnay
be set
to whatever
po6ition has
been found
to be
optimum
on each
respective
band.
Now, in
rapid succession:
(a)
Turn the CAR.
BAL.
control
clockwise
until a 51i8ht
increase
in meter
reading
is obtained.
(b)
Rotate
the PA GRID
control
for
maximurn
meter
!eading.
(c)
Rotate
the PA
PLATE
control
for minimurn
meter leading.
(d)
Adjust
car. bal.
for a leading
oI
150
rna.
IMPORTANT
-
Tuning
the PA
PLATE
for minimum,
or
"dip,
"
i3 known
ag
i
resonatingri
the
power
amplifiel
plate circuit,
and i3 vety
ilnportant
to
preserving tube
life. If the
transceive!
is held in
Tran8rnit
or
TUNE
position
for more
than
a few
seconds
while
out
of resonance and
with sorne
glid drive,
the
6HF5
tubes rnay
be severely
damaged.
For
this reason we
tepeat:
CAUTION
-
Do
not hold
the transceiver
in Trans-
mit
or TUNE
position for
any length
of
time without
rrdiPPingri
the PA
PLATE control.
The
PA GRID
rnust
first
be
Ipeakedrr
as in
(b),
above,
and
this requires
some carrier
supplied
as described
in
(a),
so it
can
be seen that
these stePs
rnust
be
p€rformed
quicklY. If the
PA
LOAI)
control
is too far
clockwise,
it lnay