Swann 1200-X User manual
MC
RANGE
14
9
10
REVERSE
FORWARD
RELATIVE
OUTPUT
TUNE=CW
BYPASS,
1
,
SSB
CYGNET
x
.
LINEAR
AMPLIFIER
Swan
Model
1200-X
POWER
RATING
1200
Watts
PEP
Input
in
SSB
Mode.
700
Watts
Input
on
CW,
and
300
Watts
Input
on
AM.
FREQUENCY
RANGE
3,000
—
4,500
ke
6,000
—
9,000
kc
11,000
—
16,000
kc
16,000
—
23,000
kc
23,000
—
35,000
kc
.
TUBE
COMPLEMENT
Four
6LQ6’s
in
Grounded
Grid,
Super-Cathode-Drive
Circuit.
DRIVE
REQUIREMENTS
100-125
Watts
minimum
for
full
output.
METER
Reads
Cathode
Current,
and
Relative
Forward
and
Re-
flected
Power.
CATHODE
CURRENT
Amplifier
Includes
Transmit-Receive
Relay
control
for
simple
oper-
ation
with
a
Transceiver.
External
ALC
connection.
Wide
range
Pi-Output
Circuit
matches
52
or
75
Ohm
coax
cable
or
variety
of
other
load
impedances.
POWER
SUPPLY
Computer
grade
electrolytic
capacitors,
55
mfd,
filtering
at
1200
VDC
rating.
Silicon
Rectifiers.
AC
Input:
117
volts,
50-60
cycles,
400
watts
average
input
with
voice
modulation.
DIMENSIONS
13”
wide
x
5%”
high
x
10%”
deep.
WEIGHT
27
lbs.
INSTALLATION
CAUTION
Never
remove
the
cabinet
or
bottom
cover
when
power
line
voltage
is
connected.
Highly
lethal
voltage
is
used
in
this
amplifier.
Allow
at
least
one
minute
for
capacitors
to
discharge
after
turning
the
amplifier
off
and
pulling
the
plug.
GENERAL:
i
nN
Refer
to
the
pictorial
in
Figure
1
when
making
the
instal-
lation.
Connect
a
short
length
of
coaxial
cable
(RG-58
or
RG-8)
from
the
transceiver
or
exciter
to
the
coaxial
input
jack
on
the
1200-X.
A
PL-259
type
connector
is
required
at
the
amplifier
end
of
the
cable.
This
cable
should
be
as
short
as
practical
and
preferably
not
more
than
5
feet
long.
.
Connect
the
relay
control
cable
to
the
auxiliary
relay
jack
on
the
Swan
270B.
When
using
the
1200-X
with
other
Swan
transceivers,
it
will
be
necessary
to
perform
the
following
steps:
Remove
bottom
of
transceiver
and
install
RCA
type
phono
jack
on
the
back
of
the
transceiver.
Be
sure
to
insulate
the
jack
from
the
chassis.
1200
X
IN
UT
ALC
:
ADJ
(b)
Locate
Relay
K1,
and
connect
a
wire
from
the
+12
volt
side
of
the
relay
coil
to
the
center
conductor
of
the
phono
jack.
Connect
another
wire
from
the
other
side
of
the
relay
coil
to
the
common
side
of
the
Phono
Jack.
By-pass
both
terminals
of
the
Phono
jack
with
.01
mfd
disc.
capacitors.
(TVI
suppression.)
Install
phono
plug
from
1200-X
into
phono
jack
on
transceiver
for
relay
control
of
the
amplifier.
On
On
2)
©
Connect
the
antenna
coax,
or
dummy
load,
to
the
output
jack.
If
a
low
pass
filter
is
to
be
installed
to
reduce
TVI,
connect
it
between
the
output
jack
and
the
antenna.
.
For
transceivers
or
exciters
other
than
Swan,
refer
to
the
inset
detail
on
the
1200-X
schematic
for
the
necessary
changes
to
the
relay
circuit.
Locate
the
terminal
strip
with
the
black
ond
red
wires
from
the
control
cable.
The
Terminal
strip
is
located
near
the
rear
of
the
chassis
next
to
where
the
relay
control
cable
exits
from
the
chassis.
.
See
the
special
instructions
at
the
back
of
the
manual
for
connecting
and
operating
the
ALC
with
the
270B
or
500CX
Transceivers.
COAX
TO
ANT
FIGURE
1.
REAR
VIEW
—
TYPICAL
INSTALLATION
USING
SWAN
270B
OPERATION
TUNING
INSTRUCTIONS:
(4)
Turn
the
1200-X
on.
The
meter
indicating
light
and
the
6LQ6
tube
filaments
will
be
lit.
Turn
the
1200-X
FUNCTION
SWITCH
to
the
“BY-PASS”
position.
Tune
the
exciter
or
transceiver
first.
Exciter
output
will
be
shunted
around
the
linear
amplifier
by
the
internal
relay,
and
will
go
to
whatever
antenna
or
load
is
connected
to
the
output
connector.
The
“OUTPUT
METERING”
control
sets
the
meter
level,
which
will
indicate
exciter
output
when
the
“RELA-
TIVE
OUTPUT”
switch
is
in
the
“FORWARD”
posi-
tion,
and
may
be
used
conveniently
as
a
tuning
meter.
Simply
adjust
the
exciter
controls
for
maximum
out-
put,
using
whatever
tuning
procedure
is
prescribed
for
the
particular
exciter.
Then
switch
the
exciter
back
to
standby
or
receive
position.
Turn
the
1200-X
FUNCTION
SWITCH
to
the
“TUNE-
CW”
position.
Set
the
BANDSWITCH
to
the
proper
band
position,
and
the
P.A.
LOAD
to
9
o’clock.
Turn
the
Mic.
Gain
control
down
on
the
exciter
or
trans-
ceiver,
and
be
sure
the
carrier
has
been
balanced
out.
Then
switch
the
exciter
to
the
normal
voice-transmit
position.
With
Swan
Transceivers,
this
may
be
done
by
pressing
the
Push-To-Talk
button
on
the
Micro-
phone,
or
by
placing
the
transceiver
FUNCTION
SWITCH
in
the
“TRANS”
position.
If
the
relay
con-
trol
circuitry
is
properly
connected
and
functioning,
the
1200-X
is
now
in
transmit
mode.
The
6LQ6
tubes
will
now
be
drawing
“idling
current”
of
about
100
ma.
By
turning
the
“OUTPUT
METERING”
control
fully
counterclockwise
to
the
off
position,
you
will
read
cathode
current.
Switch
the
exciter
to
the
“TUNE”
position.
(If
an
exciter
or
transceiver
with
more
drive
than
the
Swan
260,
270,
or
270B
is
used,
it
is
recommended
that
the
drive
be
kept
down
to
approximately
100
watts
out-
put.
With
the
Swan
350,
350C,
500,
500C,
or
SOOCX,
this
is
done
by
inserting
approximately
250
ma.
of
carrier
rather
than
switching
to
the
“TUNE”
posi-
tion.)
Quickly
adjust
P.A.
TUNE
on
the
1200-X
for
maximum
output,
as
indicated
by
the
meter
in
“OUT-
PUT
METERING”
position,
and
the
“RELATIVE
OUTPUT”
switch
in
the
“FORWARD”
position.
Then
go
back
to
the
exciter
and
re-adjust
its
P.A.
TUNE
for
maximum
output.
(It
may
have
changed
slightly
when
switched
into the
amplifier
cathode
circuit.)
Next
advance
the
P.A.
LOAD
control
on
the
1200-X
for
increased
output,
and
then
alternate
be-
tween
adjusting
P.A.
TUNE
and
P.A.
LOAD
until
the
highest
possible
output
indication
is
reached.
Then,
advance
the
P.A.
LOAD
control
about
1
number
higher
and
adjust
P.A.
TUNE
for
maximum
output.
_|
position
for
longer
than
30
seconds
at
a
time.
This
last
tuning
adjustment
will
provide
best
linearity
and
efficiency.
The
output
reading
is
a
relative
indication,
and
will
vary
considerably
with
different
antenna
loads
as
well
as
with
frequency.
The
cathode
current
should
read
approximately
500-600
ma.
This
reading
is
based
on
100
watts
of
drive.
With
more
driving
power
the
cathode
current
will
of
course
read
higher.
CAUTION
Do
not
keep
the
exciter
or
transceiver
in
tune
This
caution
note
concerns
the
exciter
more
than
the
1200-X,
but
since
the
6LQ6
power
amplifier
tubes
are
operating
at
full
input
dur-
ing
tune,
the
time
should
always
be
kept
short.
If
longer
time
is
required,
switch
to
standby
for
a
minute,
and
then
back
to
tune
for
30
seconds.
With
experience
in
tuning
procedures,
it
will
be
found
that
30
seconds
is
more
than
enough
time.
Having
followed
the
preceding
tuning
procedures,
now
switch
the
1200-X
to
“SSB”
position,
and
the
OUT-
PUT
METERING
control
to
CATHODE
CURRENT.
Apply
SSB
voice
excitation
from
the
transceiver
or
driver,
and
advance
its
Mic.
Gain
control
for
a
peak
reading
of
300-400
ma.
CAUTION
1)
Exercise
great
care
in
setting
the
Mic.
Gain
control.
It
is
quite
easy
to
produce
higher
meter
readings,
but
flattopping
and
distortion
will
result.
2)
Do
not
switch
the
exciter
into
“TUNE’”’
posi-
tion
when
the
1200-X
is
in
“SSB”
position.
Only
voice
modulated
excitation
should
be
applied
in
this
position.
Monitoring
and
tuning
with
an
oscilloscope
is
a
highly
recommended
piece
of
test
equipment
for
the
com-
plete
amateur
radio
station.
The
scope
should
be
suitable
for
monitoring
transmitter
output
and
line-
arity.
This
instrument
will
permit
optimum
tuning
of
both
the
driver
and
amplifier,
as
well
as
continuous
monitoring
during
operations.
An
excellent
oscillo-
scope
is
the
Heath
Model
SB-610
sold
in
kit
form
by
the
Heath
Co.
of
Benton
Harbor,
Michigan.
The
instruction
book
supplied
with
this
kit
explains
in
detail
how
to
connect
and
use
the
instrument,
and
how
to
interpret
the
screen
patterns.
Other
oscillo-
scopes
may
also
be
used.
The
Radio
Amateur’s
Hand-
book,
published
by
the
ARRL,
and
the
Radio
Hand-
book
by
Bill
Orr,
published
by
Editors
and
Engineers
both
contain
detailed
information
on
the
use
of
oscilloscopes
for
transmitter
tuning
and
operation.
These
publications
are
recommended
references
for
this
purpose.
(6)
To
operate
without
the
120U-X,
simply
switch
it
to
“BYPASS”
position.
The
antenna
circuit
is
then
by-
passed
around
the
amplifier
by
the
internal
relay
and
the
transceiver-driver
will
operate
“BAREFOOT”.
However,
the
6LQ6
filaments
in
the
1200-X
remain
lit
to
allow
instant
operation
of
the
amplifier.
When-
ever
you
are
operating
“BAREFOOT”,
it
is
advisable
to
touchup
the
P.A.
PLATE
and
P.A.
LOAD
controls
on
the
exciter-driver
for
maximum.
@)
For
CW
operation
at
approximately
500
watts
input,
place
the
FUNCTION
switch
in
the
“TUNE-CW”
position.
For
full
power
CW
operation
(approximately
700
watts
input),
place
the
FUNCTION
switch
in
the
SSB
position.
RELATIVE
OUTPUT:
This
feature
gives
the
operator
a
check
on
how
the
feedline
and
antenna
looks
to
the
amplifier.
With
the
switch
in
the
REVERSE
position,
the
meter
reads
relative
reflected
power.
This
level
is
also
controlled
by
the
output
metering
control.
In
order
to
get
a
meaningful
relationship
between
forward
and
reflected
power,
it
is
recommended
that
with
the
switch
in
the
FORWARD
position,
adjust
the
OUTPUT
METER-
ING
control
for
a
reading
of
600
to
900
on
the
meter
scale.
Then
switch
to
REVERSE
without
changing
the
OUTPUT
METERING
control.
Under
these
conditions,
a
reading
of
125
to
200
or
more
on
the
meter
indicates
a
VSWR
of
2
to
1
or
more,
and
some
work
on
your
antenna
systems
would
probably
be
in
order.
EXTERNAL
ALC
CONNECTION:
The
Swan
270B
and
S5O0CX
have
ALC
already
incorporated
in
them,
but
for
those
operators
that
prefer
having
ALC
controlled
from
the
1200-X,
an
external
ALC
connection
has
been
provided
on
the
back
of
the
1200-X.
It
is
not
necessary
to
use
this
circuit
in
the
operation
of
the
1200-X.
It
will
operate
properly
with
or
without
this
circuit
being
connected
to
the
exciter-driver.
To
use
this
feature,
a
slight
modification
to
the
270B
and
500CX
is
necessary.
The
addition
of
the
circuit
in
Figure
2
or
Figure
3
is
necessary.
The
parts
necessary
for
this
modification
have
been
packed
with
your
1200-X.
The
location
of
the
phono
jack
con-
nector
is
recommended
as
shown
in
Figure
2
or
3,
in
order
to
allow
addition
of
the
Swan
NB-500
or
ICAF
accessories.
The
connecting
cable
for
the
ALC
control
Be
also
been
in-
cluded
with
your
1200-X.
ADJUSTMENT:
The
best
method
is
to
use
an
oscilloscope,
and
with
the
exciter-driver
properly
connected
to
the
amplifier,
and
both
units
properly
tuned,
adjust
the
ALC
pot
on
the
back
of
the
amplifier
so
you
cannot
flattop.
If
an
oscilloscope
is
not
available,
it
is
possible
to
adjust
the
ALC
circuit
by
watch-
ing
the
cathode
current
on
your
exciter-driver.
While
speak-
ing
into
the
mic,
adjust
the
ALC
control
on
the
back
of
the
amplifier
until
occasional
peak
readings
of
100
to
120
ma.
(for
270B),
or
200
to
225
ma.
(for
SOOCX),
are
obtained.
MAINTENANCE:
There
will
be
little
maintenance
required
in
the
1200-X
amplifier.
The
6LQ6
tubes
will
provide
thousands
of
service
hours
when
operated
according
to
instructions.
Deteriora-
tion
of
a
tube
will
generally
be
indicated
by
a
change
in
idling
current
or
inability
to
draw
normal
plate
current,
or
both.
However,
except
for
occasional
field
problems
which
may
occur
with
any
electronic
device,
the
tubes
may
be
expected
to
operate
month
after
month
and
year
after
year
with
no
problems.
In
the
grounded
grid
circuit,
matching
the
6LQ6
tubes
is
not
normally
required.
Other
components
are
also
operating
conservatively,
and
well
within
nominal
ratings.
The
electrolytic
filter
capaci-
tors
in
the
power
supply
are
computer
grade,
meaning
that
they
have
a
much
higher
degree
of
purity
and
quality
con-
trol
than
conventional
types.
Life
expectancy
of
these
filters
is
approximately
10
years.
The
silicon
diodes
used
in
the
supply
are
hermetically
sealed
and
are
not
likely
to
fail
or
wear
out.
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DIAL
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