Fluke 54200 - Explanations of BTSC Test Modes

Function Reference
BTSC Sound
5
5-53
Audio and Sound Outputs
The internal generated audio signals of channel 1 and 2 are available at the
AUDIO OUT
and the
EURO AV OUT
connectors (rear side).
The audio signals are applied to:
•
AUDIO OUT L
for channel 1 (S1 left).
•
AUDIO OUT R
for channel 2 (S2 right).
These signals are also applied to the
EURO AV OUT
pin 3 (channel 1) and pin 1 (channel
2). For the Test modes 1 to 3 no audio signals are available at the rear.
The BTSC composite signal including the Second Audio Program is available at the
MTS/PILOT OUT
connector.
The FM modulated sound carrier signal (4.5 MHz) is available at the
SOUND IF OUT
connector.
Explanations of BTSC Test Modes
Test 1
Stereo:
L = 300 Hz, R = 3.1 kHz
Each component has a level of -23 dB below the 100% audio input level. The sum L+R
leads to a level of approximately -17 dB (14.1%) below the maximum audio input level.
This signal combination is useful for adjusting the Stereo Channel Separation of BTSC-
decoders, for example, Philips TDA 9854, TDA 9855, or TDA 3833.
SAP:
fmod = 1 kHz, with 70% Audio Input Level (AIL)
This signal is useful for making THD measurements of the SAP processing on the
receiver side.
Test 2
Stereo:
L = 300 Hz, R = 8 kHz
Each component has a level of '75 µs EIM of 10%'.
The signal combination is useful for measurements of channel separation on the receiver
side especially at a higher frequency.
SAP:
fmod = 300 Hz
The level is 27% of the maximum audio input level, which corresponds approximately to
'75 µs EIM of 28%'. The level of this signal is the same as used for the standard SAP
modulation fmod = 5 kHz.
On the receiver side both signals, fmod = 5 kHz and 300 Hz (Test 2) should lead to the
same audio output level.