Kathrein MSK 24 manual Audio Carrier Distance and Level, Standard Audio carrier Nicam

TV measurement

Audio Carrier Distance and Level

TV transmitters can use a second audio carrier to transmit information using FM modulation (analogue) or in Nicam format (digital). Different frequencies are allocated to the audio carriers depending on the standard being used (see table). Audio carrier 1 is always the default setting after you have entered the channel or frequency.

Standard	Audio carrier	Audio carrier	Nicam
	1	2
B/G	5.5 MHz	5.74 MHz	5.85 MHz
D/K	6.5 MHz	6.26 MHz	5.85 MHz
I	6.0 MHz	------	6.552 MHz
M/N	4.5 MHz	4.72 MHz	------
L	AM 6.5 MHz	------	5.85 MHz
M1 (Japan)	4.5 MHz	------	------

When the audio carrier is measured, first the signal distance between the audio and the visual carriers is measured in dB. Then the absolute audio carrier level is measured in dBìV. During the measurement the loudspeakers are muted. After measurement the modulation of the audio carrier last measured can be heard.

Overview of commands in Measuring Audio Carrier Frequency
ë	[2ndF] [SC] Switch over to the Audio Carrier menu
	[1]...[2]	Switch between audio carrier 1 and	audio carrier 2
		(see table).
		With the Measuring Audio Carrier	Level button
		pressed,
	[3]	Switch over to Nicam reception
Example
	Measure the audio carrier distance and level of audio carrier 1:

0

SC: 5.50MHz	TV
LEV: -13.0dB

SC: 5.50MHz	TV
LEV: 58.5dBuV

Press [2ndF] [SC],

Now press [1] and keep the button pressed.

The LC display shows the following values for approx. 1 second:

Audio carrier distance frequency: 5.5 MHz

Audio carrier video carrier distance: -13 dB

After approx. 1 second the audio carrier level is displayed.

LC display:

Audio carrier distance frequency: 5.5 MHz

Audio carrier level: 58.5 dBìV

Release button [1].

Measure audio carrier distance and level of audio carrier 2:

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