Heathkit SB-201 - Page 47

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This procedure of tuning the Linear Amplifier should
take only a few seconds after you go through it a few
times. Note the LOAD control position so it can be
preset next time a particular band is used.
The Linear Amplifier is now loaded for operation at
maximum input power. If an oscilloscope is being
used for monitoring, a display similar to that shown
in Pictorial 22 should be obtained.
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Page 47
Turn
the
exciter
to
standby
to
remove
drive
from
the
Linear
Amplifier.
The Linear Amplifier is now ready for SSB or CW
transmission. An example of a proper oscilloscope
pattern is shown in Pictorial 23. Note that there are
sharp distinct peaks. The number of patterns or
“christmas trees”’ will depend on the individual voice
and the scope sweep speed. Set the scope for about a
30 Hertz sweep.
Oscilloscope pattern and plate meter read-
ing resulting from carrier or ‘‘single tone”
modulation. The meter indicates
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PLATE CURRENT
maximum or CW power input.
PICTORIAL 22
Oscilloscope pattern and plate meter read-
ing resulting from voice modulation.
Notice the peaks on the oscilloscope pat-
tern. They are sharp, indicating a clean
signal, and they will attain a height
slightly greater than the ‘“‘single tone”’ pat-
tern of Pictorial 22, indicating maximum
PLATE CURRENT
power input. NOTE: Plate current peak
reading is approximately 1/2 or less of
maximum ‘‘single tone’’ reading due to
meter inertia and voice characteristics.
PICTORIAL 23