DRAKE TR-4CW - CW, AM, and Special Operations

DRAKE
tion,
it
may
be
depressed
at
any
time,
thus
over-
riding
the
VOX
system.
If
VOX
operation
is
not
desired,
turn
the
VOX
gain
control
fully
counter-
clockwise.
On
SSB,
the
TR—4C
transmits
on
exactly
the
same
frequency
on
which
it
receives.
Therefore,
be
sure
that
you
have
the
signals
tuned
in
so
that
the
voices
sound
normal
before
you
answer
another
station’s
CQ,
or
break
another
QSO.
Otherwise,
you
will
not
be
transmitting
exactly
on
frequency.
If
a
key
is
used,
it
must
either
be
closed
or
unplugged
from
the
KEY
jack
for
SSB
and
AM
operation.
3-9. CW OPERATION.
To
operate
CW,
connect
a
key
to
the
KEY
jack.
If
an
electronic
keyer
is
used,
connect
it
for
grid
block
keying.
Leave
the
key
in
the
open
condition.
The
TR—4C
uses
shifted
carrier
CW.
With
this
system,
it
is
possible
to
transmit
approximately
on
the
re-
ceived
station’s
frequency
without
being
zero
beat
while
receiving.
The
transmitter
BFO
is
shifted
from
the
received
signal
frequency
by
approximately
1
kHz.
The
VFO
dial
reads
the
correct
frequency
of
a
received
signal
when
the
signal
is
tuned
for
zero
beat.
To
receive
CW
signals,
place
the
Mode
switch
in
the
X-CW
position
and
the
SIDEBAND
switch
in
the
X
position.
Tune
in
a
CW
signal
for
an
audio
pitch
of
about
|
kHz
and
adjust
the
audio
gain
control
knob
for
a
normal
listening
level.
To
transmit,
depress
the
key,
and
adjust
the
XMTR
GAIN
control
until
it
is
just
below
the
point
at
which
plate
current
no
longer
increases.
Do
not
advance
it
beyond
this
point.
Advance
the
SIDE-
TONE
control
on
the
rear
of
the
chassis
until
the
sidetone
reaches
the
desired
volume.
Adjusting
the
RCVRGAIN
knob
controls
both
the
received
signal
and
sidetone
level.
The TR—4C uses automatic transmit/receive switch-
ing. This means that it will automatically transmit
when the key is depressed and will remain in the
transmit condition during keying. It will return to
the receive condition when the key is released for a
brief period. If this period is too long, decrease the
VOX gain. Manual transmit/receive switching can
be accomplished by connecting an external switch
to the push-to-talk circuit of the MIC jack.
3-10. AM OPERATION.
For AM operation, the Mode switch should be in
the X-AM position and the SIDEBAND switch
should be in the X position. If a key is used, it
should be left closed or unplugged. Tune in AM
signals for most pleasing audio. This will not neces-
sarily coincide with maximum S meter reading. The
same procedure should be followed in setting the
various gain controls on AM as on SSB, except that
the XMTR GAIN control should be adjusted for
plate current peaks of 0.2 to 0.25 Amperes when
talking into the microphone in a normal voice. Care
should be taken to stay within these limits since
the transmitter AGC does not operate on AM.
3-11. OPERATION NEAR BAND EDGES.
When operating near the edge of a band, be sure to
check the dial calibration as described under tuning
procedure. When working SSB be sure to use the
sideband that will be inside the band. On AM and
CW, the transmitted carrier will be | kHz higher or
lower than the indicated dial frequency.
3-12. OPERATION WITH A LINEAR
AMPLIFIER.
Since the TR—4C Transceiver is conservatively rated
at 300 watts PEP input, it is doubtful if it would be
worthwhile to use a linear amplifier with a power
rating of less than 1000 to 2000 watts PEP input.
A triode type grounded grid linear amplifier with a
1000 to 2000 watt PEP rating will present a satis-
factory load to the TR—4C.
If the linear amplifier is of the grounded cathode
type with high impedance input, it will be necessary
to install a resistive pad between the TR—4C and
the linear amplifier that will present the proper
impedance to the TR-4C. Such a pad must be
made of non-inductive resistors and must have
adequate power handling capacity. Antenna switch-
ing should be accomplished as shown in figure 2-7.
Most linear amplifiers have these relays built-in.
To properly operate the TR-—4C with a linear
amplifier proceed as follows: