Hallicrafters HA-1, Инструкция по эксплуатации и обслуживанию

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SECTION IV
FUNCTIONS OF OPERATING CONTROLS
4-1. FUNCTION SWITCH
The FUNCTION control is a four-position rotary switch: (1) turns the unit ON
and OFF, (2) selects low or high speed operation, and (3) has a center HOLD
position for transmitter tuning purposes (key down).
4-2. SPEED CONTROL
The SPEED control provides a means of adjusting the keying speed between
10 and 30 WPM when the FUNCTION switch is in the LOW position or between
25 and 65 WPM in the HIGH position.
4-3. SIDETONE CONTROL
The SIDETONE control (knurled shaft), accessible at the rear of the unit,
adjusts the amplitude of the keyed monitor tone.
4-4. BALANCE CONTROL
The BALANCE control (screwdriver slot shaft), mounted at the rear of the
unit, differentially adjusts the gain of tube V3 to compensate for tube section
differences and aging. The adjustment should remain fixed for long periods of
time and need only be readjusted when V3 is replaced or when major service has
been performed.
To adjust the BALANCE control proceed as follows
(1) Turn the control to its maximum counterclockwise position. The unit
will key a continuous dash. Advance the control in the clockwise
direction, and note the point at which the dash stops.
(2) Turn the control to its maximum clockwise position and close the key
to dash. The unit will key a continuous series of dots as long as the
key is held closed to dash. Adjust the control counterclockwise to the
point where self-completing dashes are formed. Note this setting.
(3) Set the control midway between the points noted in step 1 and 2
above. The BALANCE control is now properly set and should require
no further attention.