Filter
Top Products
Performance Verification
4–26
1780R-Series Service Manual
c. Set the generator output frequency to 50 kHz (reference). Set the
generator output amplitude so the Waveform CRT display is exactly
714 mV or 100 IRE for NTSC (or 700 mV for PAL) in amplitude.
d. Set the generator output frequency to 1 MHz.
e. Check that the Waveform CRT display amplitude is 714 mV for NTSC
(700 mV for PAL) in amplitude within ±2% or ±14.3 mV or 2 IRE for
NTSC (14.0 mV for PAL).
f. Set the generator frequency to each of these frequencies: 3.58 MHz
(4.43 MHz for PAL), 5 MHz, 8 MHz, and 10 MHz.
g. Check that the Waveform CRT display amplitude is 714 mV for NTSC
(700 mV for PAL) in amplitude within ±2% or ±14.3 mV or±2 IRE for
NTSC (±14.0 mV for PAL) for each frequency given in part f. of this
step.
h. Set the FILTER selection to FLAT.
i. Disconnect the sine wave signal from the AUX IN connector.
16. Check Auxiliary Output Frequency Response
Requirement: Flat frequency response from 50 kHz to 10 MHz within ±2%.
50 kHz is used as a reference.
a. Connect the leveled sine wave generator output, through a 50 W-to-75 W
minimum loss attenuator, to the CH A INPUT connector. Connect a
75 W terminator to this loop-through connector.
b. Connect a coaxial cable from the AUX OUT connector through a 75 W
feed-through terminator to the test oscilloscope Dual-Trace Amplifier
Ch 1 input. See Figure 4–9.
c. Set the test oscilloscope Dual-Trace Amplifier controls as follows: Ch 1
Volts/Div to 0.1 V, Input Coupling to DC, Display Mode to Ch 1,
Trigger Source to Ch1, and BW to Full. Set the Time Base controls as
follows: Mode to Auto, Coupling to DC, Source to Int, and Time/Div to
1 ms.
d. Adjust the generator output frequency to 50 kHz (reference) and the
amplitude to display exactly 714 mV in amplitude for NTSC (700 mV
for PAL) on the test oscilloscope CRT. Note this exact amplitude for use
as a reference.
e. Set the generator output frequency to 1 MHz.
f. Check that the test oscilloscope displayed amplitude is within ±2% or
±14.3 mV for NTSC (±14.0 mV for PAL) of the amplitude noted in part
d. of this step. Take into account the generator flatness error.