Gonset G-66 - Operation; Function Switch and Volume Control; Tuning; BFO Adjustment

OPERATION
FUNCTION
SWITCH
ond
VOLUME
CONTROL
The
function
switch
provides
for
reception
of
phone,
CW,
or
single-sideband
signals.
Noise
limit-
ing
may
be
applied
to
phone
signals
as
desired.
In
addition,
a
standby
position
is
included
to
be
used
when
automatic
receiver
muting
is
not
employed.
With
the
switch
in
either
of
the
ANL
positions,
a-v-c
voltage
is
applied
to
the
r-f
and
i-f
amplifters
and
the
volume
control
is
connected
only
to
the
audio
portion
of
the
receiver.
When
the
switch
is
in
CW-SSB
position,
the
a-v-¢
function
is
removed
from
the
circuit
and
the
volume
control
controls
the
t-f
and
i-f
amplifiers
while
the
audio
amplifier
operates
at
full
gain,
Thus,
optimum
gain
adjustment
is
ob-
tained
with
a
single
control,
a
desirable
feature
for
mobile
operation.
TUNING
Tuning
is
indicated
by
an_
illuminated
slide-tule
dial
which
displays
only
the
band
ia
use.
The
gear
ratio
to
the
tuning
knob
is
unusually
high
co
permit
non-critical
tuning
under
mobile
operating
condi-
tions.
For
¢his
reason
the
tuaing
knob
has
a
“broad
tuning”
feel
and
this
should
not
be
thought
of
as
Jack
of
selectivity
within
the
receiver.
The
receiver
is
accurately
calibrated
hefore
leaving
the
factory.
Aging
of
components,
however,
may
cause
the
calibration
to
drift
slightly
after
extended
use.
An
oscillator
trimmer,
Eatreclice
by
the
flat
knob
on
the
left
side
of
the
receiver,
is
provided
to
readjust
the
calibration
against
a
transmitter
crystal
of
known
frequency
or
any
other
accurate
signal
source.
The
receiver
is
factory
calibrated
with
the
set-screw
hole
of
the
trimmer
control
knob
facing
directly
forward
and
it
should
be
left
in
this
position
except
when
setting
the
calibration
to
a
signal
of
known
accuracy.
Due
to
the
method
in
which
the
calibration
trimmes
is
connected
in
the
bandspread
circuit,
a
slight
movement
of
the
knob
has
a
large
effect
om
¢he
broadcast-band
calibration.
This
is
especially
true
at
the
high-frequency
end
of
the
dial.
For
this
reason
the
calibration
knob
should
always
be
returned
to
the
factory
setting
(set-screw
hole
directly
forward)
when
tuning
the
broadcast
band.
BFO ADJUSTMENT
The
beat-frequency
oscillator
(BFO)
operates
with
the
function
switch
in
CW-SSB
position.
The
front-
panel
BFO
adjustment
kaob
is
calibrated
to
receive
SSB
signals
transmitting
either
the
upper
or
lower
sideband.
With
the
knob
in
position
A,
upper
side-
hand
signals
are
received
on
all
bands
except
20
meters.
On
20
meter
lowet-sideband
signals
are
passed,
When
the
knob
is
in
position
B,
the
opposite
sideband
is
received.
Since
these
positions
are
only
approximate
settings,
careful
adjustment
of
che
knob
is
required
for
good-quality
SSB
reception.
For
CW
signals
the
BFO
knob
may
be
set
near
either
position
and
adjusted
for
the
desired
pitch.
ANTENNA TRIMMER
‘The
antenna
trimmer
is
effective
on
all
bands
and
should
be
adjusted
for
maximum
signal
strength
or
background
noise.
On
all
bands
except
10
meters,
setting
the
antenna
trimmer
on
a
signal
near
the
cen-
ter
of
the
tuning
dial
will
adjust
the
receiver
for
good
reception
throughout
the
band.
On
10
meters
some advantage
is
usually
gained
by
adjusting
the
tcimmer
to
each
signal
as
it
is
tuned
in,
S METER
The
S
meter
indicates
a
signal
increase
of
about
6
db
for
each
meter
division
up
to
$9.
The
meter
is
factory
adjusted
to
indicate
"S
zero”
with
the
antenna
disconnected
and
the
antenna
trimmer
adjusted
for
maximum
background
noise.
If
desired,
the
ao-signal
reading
may
be
readjusted
by
inserting
an
insulated
aligament
tool
through
the
rubber
grommet
on
the
right-hand
side
of
the
receiver
case.
Do
not
use
a
metallic
screwdriver
for
this
adjustment;
the
S-meter
adjustment
is
at
B-plus
potential.
The
zero
adjust
ment
on
the
meter
face
is
factory
set
so
the
meter
oes
slightly
off
scale
to
the
right
when
the
receiver
is
turned
off.
This
is
normal
and
is
required
to
pro-
vide
accurate
readings
on
very
strong
signals.
BROADCAST-BAND OPERATION
To permit more compact construction the double-
conversion feature of the receiver is retained on the
broadcast band. On any receiver with an intermediate
frequency
higher
than
the
received
signal,
certain
combinations
of
incoming
signal
frequencies
can
cause
“cweets”
or
whistles
on
some
stations.
Nor-
matly
this
condition
is
not
toublesome
and
occurs
only
in
areas
where
many
high-powered
broadcast
stations
are
operating.
If
trouble
of
this
nature
is
found,
reduce
the
length
of
the
BC
antenna
to
a
minimum
consistent
with
adequate
signal
strength.
If
a
separate
BC
antenna
is
not
used,
turn
the
an-
tenna
coupling
adjustment
(located
between
the
two
antenna receptacles) to the position most counter-
clockwise chat still allows good broadcast reception.
Best broadcast reception ts obtained with the auto-
matic
noise
lithiter
switched
off
since
¢chis
circuit
distorts
the
audio
output
to
some
extent,
The
effect
is
objectionable
only
when
receiving
high-quality
music.