Heathkit SB-401 Assembly Manual page 103

FIGURE 1-2
BAND: This swit ch determines the amateur
band or the 500 kHz segment of the band on
which the Transmitter i s to operate.
LMO DIAL KNOB: This kn ob is used to set
the Transmitter for the desired operating fre-
quency of the selected band when the internal
LMO is used. '
MODE: This switch p ermits the operator to
select the desired mode of operation, such as
LSB, USB, CW and TUNE.
FUNCTION: This switch is set f or the desired
Transmitter function, such as OFF, STBY, TRCV, 1:-----
TRAN, and SPOT.
METER: Setting this switch t o its various
positions gives the operator a qui ck check
of the Transmitter functions, on the meter.
DRIVER: This control is adjusted for maximum
meter indication (REL PWR). It tun es the
driver stage for maximum output.
FIGURE 1-1
METER: Indicates grid current 0-1 rna, fin al
plate current 0- 500 rn a, ALe maximum modu-
lation (right edge of ALC area; final plate
voltage 0-1000 volts, and relative power 0-10.
ZERO SET KNOB
FINAL: This control is adjusted for maximum
meter indication (REL PWR). It tunes the Trans-
mitter for maximum output by r-esonating the
final tank.
LEVE L: This control adjusts for maximum per-
missable (midscale top edge of ALe meter area)
modulation without distortion t o the driver.
Also adjusts RF driv e to the drive stage in the
CW mode.
FINAL LOAD: This control is adjus ted for
maximum meter indication (REL PWR). It tun es
the Transmitter for maximum output by matching
the output impedance to the antenna.
FREQ. CONTROL: This switch permits the se-
lection of either the internal LMO or the ex-
ternal LMO in the SB-301 Receiver. In the
UNLOCKED posttion, the LMO in the Tr-ans.,
mitter and th e LMO in the Recei ver operate
independent of each other. In th e LOCKED
(RCVR) positron, the LMO in the Receiver con-
trols both units.
GR
3395.4kHz CW
(INSTALL IN
MIDDLE SOCKET )
Y9
Y 11
INSET
3393.6
3395 4
3396.4
,~-t
fAlWlt5l
I - - - I
SIDEBAND AMPLITUDE BALANCE: This con-
trol is adj usted for equal amplitude of each
sideband.
~
""-~@J
I
'©A
CARRIER NULL: Balances the modulator to
~1
eliminate carrier from the output signal for the
/1
USB or LSB operating mode.
NEUTRALIZING: This capacitor is adjusted to
a
--t~
I
aJ
balance out
the grid-to-plate ca pacity of the
-r)
output tubes.
-,
~
o~
r\
~II
•
~Vl ~
ALC ADJUST: This control is set for a 0
e
,-
e meter indication (ALC) with no modulation.
V \
®jf'
QJ 0
~
0 8>
~' /
<,
V2
TONE OUTPUT LEVEL: This control is usedto
0 :> 0 '-.
set the level of CW tone supplied to the receiver
ill
(/)
-,
RELATIVE POWER: Adjust this control for
@
./
for monitoring the CW signal being transmitted.
a meter
reading of 2/3 full scale when the
0 0
J)
transmitter • fully loaded 80 meters,
p
0
<ill
IS
on
0
~
0 <D
,
'.....!'J
'i..-i
ANTI-VOX: This control is adjusted so audi o
0
p
0
If~(~
(_)
/
-,
r.
output from the receiver does not trip the
\\
0
@
..
transmitter VOX cir cuit for VOX and CW op-
10
\V
"V lj
fr
0 0
eration.
)
~
~~~
Q~QQ
:v
12
(
...
VOX DELAY: This control is adjusted for the
BIAS ADJUST: With driver tub e (V9) removed
...
7
~
"- ./
desired hold-in time after th e operator stops
and key down, adjust this control f or 50 rna of
@f r
talking in SSB (VOX) or keying in CWoperation.
plate current.
-
\\
Q
r- : .::
I (
,-
- .
\
~~
VOX GAIN: This control is adjusted for the de-
="0
<,
~~
sired microphone sensitivity for VOXoperation.
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