Operating instructions

ACCEPTANCE TESTING
5-18
(5) This step is a functional check only and confirms that the audio filters switch in correctly
with minimal insertion loss. Press [HELP/SETUP], [Setup], [AF Filters], [Factory Preset],
[Return], [Return], [Return].
• Set the UUT AF filter to 15 kHz LP and check that the UUT voltmeter indicates within
±6% ±3 mV ± resolution of the level measured with the 50 kHz LP.
• Repeat with the 300 to 3.4 kHz BP filter.
• Repeat with the 50 to 15.0 kHz BP filter.
• Set the LF generator to 100 Hz and set the UUT filter back to 50 kHz LP. Note the
reading and then set the UUT filter to 300 Hz LP. Check that the UUT voltmeter
indicates within ±6% ±3 mV ± resolution of the level measured with the 50 kHz LP.
(6) Set the UUT AF filter to 50 kHz LP.
(7) Set the LF generator to frequency 50 Hz level 1 V RMS (adjust until DVM indicates as close
to 1 V as possible). Check that the level indicated on the UUT voltmeter is within ±3%
±3 mV ± resolution of the level indicated on the DVM.
(8) Repeat step 7 with LF generator frequencies of 100 Hz, 500 Hz, 10 kHz, 30 kHz and 50 kHz.
(9) Set the UUT AF input to DC coupled and substitute the LF generator with the DC power
supply. Set the external DVM to monitor DC volts.
(10) Set the DC supply to 25 V (adjust until DVM indicates as close to 25 V as possible). Check
that the level indicated on the UUT voltmeter is within ±1% ±50 mV ± resolution of the level
indicated on the DVM. Repeat this step with the DC supply set to 50 V.
AF distortion & SINAD meter
Specification
Frequency range:
1 kHz
Distortion meter accuracy
±5% of reading ± 0.5% distortion
SINAD meter accuracy
± 1 dB
(1) Refer to Results table 5-20 on page 5-38. Connect UUT AF INPUT to UUT AF GEN OUT.
(2) Set the UUT to [AF TEST], [Audio Gen], [FREQ] 1 kHz, [LEVEL] 1 V. Press
[Gen 1/Gen2] to select AF Gen 2, then [FREQ] 400 Hz, [LEVEL] 20 mV, [ON]. This
should cause AF Gen 1 to be set to 1 kHz, 1 V, and AF Gen 2 to 400 Hz, 20 mV. If these
values are not set, make the required adjustments to achieve them.
(3) Press [Return], [Audio Meter], [DIST/S-N], [DIST’N] to switch the UUT distortion meter
on.
(4) Check that the distortion meter reads between 1.4 and 2.6% distortion, i.e. 2% distortion
±5% of reading ±0.5% distortion.
(5) Set AF Gen 2 level to 250 mV.
(6) Select AF Gen 1 level and adjust until the UUT voltmeter reads 1.00 V.
(7) Check that the distortion meter reads between 23.2 and 26.8% distortion, i.e. 25% distortion
±5% of reading ±0.5% distortion.
(8) Press [Return], [DIST/S-N], [Sinad] to switch the UUT SINAD meter on.
(9) Check that the SINAD meter reads 12 dB ±1 dB.