TECH TE-22 User manual

OPERATING MANUAL
SINE SQUARE WAVE
AUDIO GENERATOR

TECHNICAL SPECIFICATIONS
Sine Wave Range................ 20 Hz - 200K Hz in 4 bands.
Band A 20 - 200 Hz
Band B 200 - 2,000 Hz
Band C 2,000 - 20,000 Hz
Band D 20,000 — 200,000 Hz
Square Wave Range .............. 60Hz - 30K Hz.
(5% tilt at 60 Hz, 5% rounding
at 30K Hz.)
Read on same scales as Sine Waves
Calibration Accuracy ...........4. +3% +2 Hz
Frequency Response ............ +1.5db, 60 Hz to 15OK Hz.
Output Voltage:
Load Impedance- 1M ohm ...... 7 V. (max,)
Load Impedance - 10M ohm ..... 5 V. (max.)
Tube Complement .............. 7°high, 10-1/2’’wide, 5-3/8’’deep.

OPERATING INSTRUCTIONS
. Rotate the Tuning Control dial until the basic setting for the desired frequency is
lined up beneath the hair-line. Frequency settings are indicated by the inner scale.
The outer scale is a vernier, for ‘‘fixing’’ settings accurately.
. Set the Band Selector switch at the position which will provide the multiplication
factor needed for a given frequency output. If Fx1 is selected, frequencies may be
read directly from the Tuning Control dial. If Fx10 is selected, multiply the
Tuning Control setting by 10 in order to determine the frequency of the audio
output signal. If Fx100 is selected, multiply the Tuning Control setting by 100.
If Fx1000 is selected, the Tuning Control setting must be multiplied by 1000.
. Set the Wave Form switch at the sine or square wave position, as desired.
. Shift the Off-On switch to the ON position. Allow at least five minutes for warm-up.
. A shielded test cable, terminated with banana jacks at one end and alligator clips
at the other, has been supplied. Make sure that the shielded portion of the cable is
always connected to the instrument’s black output terminal.
NOTE: Never connect the shield lead directly to the chassis of AC/DC equipment.
To prevent danger of shock, place a capacitor (approximately S5ufd, 400v) in
series with the shield lead before connecting it with such equipment.
. Adjust the Amplitude control to suit your requirements.

TUNING DIAL CONTROL: WAVE FORM SWITCH:
Selects the basic frequency Selects sine or square
setting. wave output.
\ |
OUTPUT TERMINALS:
Multi-connection type
binding posts for trans-
fer of signal via output
cables.
PILOT
LIGHT
T
OFF-ON SWITCH: ~ BAND SELECTOR SWITCH: \— AMPLITUDE CONTROL:
Energizes the unit. Selects the factor by which Adjusts amplitude of out-
Note the red pilot the basic frequency setting put signal,
light. must be multiplied.
FIGURE 1 LOCATION AND FUNCTION OF CONTROLS

CALIBRATION
The TE-22 is factory calibrated. After long use or parts replacement, however, it will
probably be necessary to readjust the unit. Only one control is involved in calibration;
a trimmer capacitor installed atop the main tuning capacitor. For calibration you will
need an oscilloscope — preferably, one having a 60 Hz test output.
Procedure
1. Two retaining screws will be found at the back of the case, and two phillips-head
screws are located at each corner of the escutcheon plate. Remove these screws,
lay the instrument on its back and lift the chassis out of the case.
2. Set the Band Selector switch at the Fx1 position.
3. Set the Tuning Control dial at 180 on the inner scale.
4. Connect the oscillator’s output terminals to the vertical input terminals of the
oscilloscope.
5. If the oscilloscope has 60 Hz output terminals, connect them to its horizontal
input terminals. If the oscilloscope has no 60 Hz output terminals, the secondary
of a 6.3 volt filament transformer can be used to provide the necessary signal.
6. Adjust the oscilloscope controls for approximately equal “x” and “y” axis
deflection.
7. Using a non-conducrive alignment tool, adjust the oscillator’s trimmer capacitor
until the oscilloscope reproduces the pattern illustrated in Figure 2. Adjust the
capacitor until the pattern remains as nearly stationary as possible.
3:1 1:3
FIGURE 2 FIGURE 3
The calibration is completed. As a check, set the Tuning Control dial at 20 on the
inner scale (with the Band Selector switch still at the Fx] position). A trace similar to
Figure 3 should appear on the oscilloscope screen. Finally, set the Tuning Control dial
to sixty on the inner scale. A trace similar to any one of the patterns shown in
Figure 4 should appear on the oscilloscope screen.
CEOS 180°
FIGURE 4

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