TM
11-6625-255-14/TO
33A1-13-170-1
Section Il. DESCRIPTION AND DATA
top and rear of the chassis. All operating controls and
1-7. Purpose and Use
connecting binding posts for standard operation are
Spectrum Analyzer TS723(*)/U is used to measure
on the front panel.
harmonic distortion and noise level in audio-
b. Additional Equipment Required.
frequency (af) amplifiers. Measurements of distor-
(1) A shielded test cable with banana plug con-
tion are made in percentage or in decibels (dB), and
nectors is the only component required to operate the
measurements of noise are made in effective values
spectrum analyzer test unit.
or root mean square (rms) values or in dB values
(2) An oscilloscope or a linear radiofrequency
referred to one milliwatt (row) across 600 ohms
(rf) detector will extend the usefulness of the equip-
(dBm). The spectrum analyzer may also be used as an
ment.
alternating current (at), vacuum-tube voltmeter
(3) When relay rack mounting is desired, a stan-
(vtvm) to measure ac signals as low as 0.003 volt.
dard 19-inch wide equipment rack is required.
1-8. Description
1-9. Differences Between Models
a. General. The spectrum analyzer consists of a
For information detailing differences between
models, refer to table 11 and figures 31, 32, and
panel-chassis assembly with a bottom cover and a
perforated or louvered metal cover that encloses the
3-3.
Table 11. Differences Between Models
Item
TS-723A/U
TS-723B/U
TS-723C/U
TS-723D/U
Components, finished
Commercial . . . . . . . . . ... Militarized . . . . . . . . . . . . . Militarized . . . . . . . . . . . . . Militarized.
construction.
9 louvers at rear.
Cover
Perforated.
9 louvers at rear.
9 louvers at rear.
Potentiometer R4.
Signal AF INPUT control,
Signal INPUT control.
Signal AF INPUT control.
Signal AF INPUT control.
Not used.
Binding posts (E5 and E6)
Not used.
Not used.
AF-RF INPUT.
Not used.
Selector switch (S2).
AF-RF.
Not used.
Not used.
Indicator lamp.
Mounted on front panel.
Mounted on front panel.
None.
Mounted on front panel.
Mounted on front panel.
Fuses and power cord.
Mounted on front panel.
Mounted at rear of chassis,
Mounted on front panel.
Mounted on front panel.
Spare fuseholders.
Mounted on front panel.
Mounted on front panel.
None.
Marked FREQUENCY,
FREQUENCY tuning
Marked FREQUENCY
Marked FREQUENCY.
Marked FREQUENCY,
COARSE, FINE.
COARSE, FINE.
dials
(Course and Fine)
White . . . . . . . . . . . . . . . . . White . . . . . . . . . . . . . . . . . Black . . . . . . . . . . . . . . . . . Black.
Engraved panel marking
115-230V switch.
None.
None
At rear of chassis.
At rear of chassis.
METER RECTIFIER
V14.
CR1 and CR2.
V14.
V14.
circuit.
residual components, Distortion
1-10. Tabulated Data
introduced by the instrument is
The technical characteristics of Spectrum Analyzer
less than 0.1 percent.
TS723(*)/U areas follows:
Sensitivity . . . . . . . . . . . . . . . . . Distortion levels as low as 0.3 per-
cent may be measured full scale.
Levels of 0.1 percent are ac-
Distortion measurement
Fundamental frequency from 20
range
curately readable.
Hz to 20 kHz.
2 percent from 20 Hz to 20 kHz.
Frequency calibration ac-
Noise amplifier gain . . . . . . . . 40 dB gain 1 dB from 20 Hz to 15
curacy
kHz.
Filter characteristics . . . . . . . . Fundamental frequency is rejected
Set-level amplifier gain . . . . . . 20 dB gain l dB from 20 Hz to 20
kHz 2,5 dB from 10 Hz to 100
by more than 99.99 percent, or
down approximately 80 dB,
kHz.
Second harmonic attenuation. Less than 17 percent (-1,5 dB) in
F shunt.
the fundamental range from 20
to 5,000 Hz, Less than 32 percent
Input level for distortion
Rms 1 volt, minimum.
measurement
(-3 dB) in the fundamental range
Meter range . . . . . . . . . . . . . . . . Full scale 0.03, 0.10, 0.30, 1.0, 3.0,
from 5 to 20 Hz.
10, 30, 100, 300, R.M.S. VOLTS.
Residual harmonic measure- Residual frequencies (harmonics of
DB: -30, -20, -10, 0, +10, +20,
ments
the fundamental frequency) are
+30, +40, and +50.
measured to within 3 percent
Vtvm section frequency range 10 Hz to 100 kHz.
of the full-scale value for distor-
Vtvm section frequency re-
tion levels as low as 0.5 percent.
Flat 3 percent of 1,000 Hz from
10 Hz to 100 kHz on all ranges.
sponse
Meter indications are propor-
tional to the average value of the
Meter calibration . . . . . . . . . . . . . Calibrated to read rms of a sine
1-3
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