Tektronix TYPE L Instruction Manual page 27

at the interconnecting plug between pin 1 and
ground, and between pin 3 and ground. The
voltage should be between +65 and +70 volts
on each pin.
5. V a ria b le Attenuator Balance
Adjustment
With the AC-DC
rotate the VARIABLE
back and forth while watching the crt fo r a
shift in position of the trace.
moves when the control is rotated, adjust the
upper VARIABLE ATTEN. B AL. control on
the front panel until the trace position is no
longer affected by the VARIABLE (VOLTS/CM)
control.
6. X10 V ariable Attenuator Balance
Adjustment
With the AC-DC switch at X10 GAIN
and the VARIABLE
calibrated, rotate the VARIABLE (VOLTS/CM)
control back and forth while watching the crt
fo r a shift in position of the trace.
trace moves when the control is rotated, adjust
the X10 VARIABLE
on the front panel until the trace position is
Cathode Current Test Points
(R6072)
Fig. 5-1. Bottom view of L
high-frequency coils.
AA
switch in DC position,
(VOLTS/CM) control
If the trace
AC
ATTEN. B AL. control
If the
ATTEN. B AL. control
L5902
L5942
Unit showing location of Cathode Current test points and X10-amplifier
Calibration Procedure - Type L Plug-In
no longer affected by the VARIABLE (VOLTS/
CM) control. Return VARIABLE control to
CALIBRATED position.
7. Check A C -D C Switch
Set the AC-DC switch at DC position. Apply
a 100 M ILLIV O LT square wave signal from
the AM PLITUDE CALIBRATOR to the INPUT
connector of the Type L Unit.
base line of the calibrator waveform on the
center line of the graticule. Turn the AC-DC
switch to AC. The
down centering the display on the graticule.
8. Cathode Current Adjustment
It is very important that the voltages at
the elements of V6042 be within certain limits.
These voltages can be varied over a limited
range by adjusting the control grid voltage
o f the tube. With a tube in good condition, all
o f the element voltages w ill be within proper
operating lim its if the cathode current is .17
m illiam peres--indicated by a voltage drop of
55 volts across the precision6-kilohm resistor,
R6072.
L6012
Position the
waveform should shift
H. F. P eaking
(R6692)
5-3