Swann 400 - Carrier Frequency Adjustment; PA Neutralization Procedure

I
MODEL
4OO
TRANSCEIVER
D, Alignment
and
Troubleshooting
(Cont)
3. Set
PA
grid tuning
Iully clockwise,
phone
-cw
switch
in
Phone
Position,
sideband
selector
in USB
Position.
Procedure:
Adjust bandswitch
to
band shown
and
adjust
coils for
Peak
VTVM
!eading
as
follows:
Function
Switch
Band
vFo
F req,
(t.)
Adjust
Tune*
80 4,O25
LZO',
L305,
cI507,
zL40l
Tune
40 7,
350 L204,
L304
Tune
zo
r4,500
LZ03, L303
Tune
21,500
LZ|Z, L30Z
Tune
IO
29,?00
L20r,
!301
*
Note: I{
VTVM and
field
strength
meter
exceed
ful1 scale
readinS,
gwitch
to
transmit
posltron and
insert
carrier
with carrie!
balance
control to
keep
reading
on scale.
Fietd
Btlength
meter
and VTVM
must both
Peak
at
same
time
since
it is
possible
to t|.1ne
the coils
to
the VFO
lrequency
on l0 meters.
Care
rnust
be
taken that
the coils
be hrned
pro
pe
rly.
Following
the above
Procedures,
replace
orange
wire
to
Pin
I of
terminal slriP
adjac
ent
to V5.
ALIGNMENT
OF 5T?5
KC
TILTER
TRAP
With
RF
and
AF gain at
midscale,
feed
5I?5kc
signaf
to antenna
connector
and
adj\rst
L60Z
until
heterodyne
di€aPPea!8
o! S
-meter
reads
zero'
ADJUSTMENT
OT CARR]ER
FREOUENCY
A. With
dummy
load
and
outPut meter
attached,
tun€
transceiver
for
lnaxi-
rnurn
otrtput.
B. Null
out carrier
with
PTT
Pressed
and
set
reBting
Plate
current
to 50
ma
wlth
bias
Pot.
C,
Connect
AF
generator
to MIC JACK
'
adjust
MIC,
GAIN
full CCW-
Proced|1!e:
With
AF
generator
at
1500
cP3,
increaee
MIC.
CAIN
to
P!oduce
a
100
ma,
reading
on the
meter.
Adjust
2801
for rnaxirnuln
meter
reading.
L
z.
3. Adjust
both toP and
bottom
corea
of
Zl40l for
maxirnlrm
rnetei
reading.
4. Adjust
MIC.
GAIN for
t'teter
read-
ing of 300
rna.
5.
Set AF
generator
to 300
cPs. Adjust
C1507
Ior
meter
reading
of 75 ma.
6. Repeat
stePs
I through
5 for
USB
operation,
adju6ting
C 1506.
PA NEUTRALIZATION
With
P. A.
coatse
load in
po6ition
I, set
{req.
to 14. 150,
PA
Plate
control at
9
orclock,
insert
carrier
and
peak P. A.
Crid
control,
adj\rsting
Car.
Bal.
con-
trol for 200
MA,
Turn
PA control
slowly
thlough
iesonance.
Cathode
current should
diP
srnoothly
and
rise to
2OO MA
on
the 1oll caPacitY
side of
re6onance.
If,
instead,
there
i6
a
peak
above ZOO
MA
either
side
of the dlP'
stop
rotation
of the
PA
plate control
at
t9