Finding Interference Frequencies; Before The Soundcheck - AKG SR 4500 Mode D'emploi

The Environment Scan function automatically searches the receiver's entire frequency band from Start to Stop (see Man-
ual Supplement) for interference frequencies. During the search, the audio output is muted and the display indicates
the frequencies in MHz as they are scanned.
The frequency spacing for the automatic scan is 100 kHz. Frequencies whose field strength exceeds the factory-set
threshold (or the threshold you may have set using the Threshold function in the "X-TRA" menu) are defined as inter-
ference frequencies and saved in a scan list. Once the scan is completed, you can scroll through the scan list.
The receiver can store a maximum of eight interference frequencies. As soon as the Stop frequency is reached or the
scan list is full, the scan will be stopped automatically.
Venues that are extremely hostile to RF transmission may make it necessary to change the Environment Scan thresh-
old setting. You can change the setting using the ">THRESH<" function in the "X-TRA" menu.
1. Select "SCAN" -> "ENVIRO".
2. Press the SETUP control briefly. The display will change to ">START<".
3. a) To start the scan, press the SETUP control briefly. The scan will start and the display will show the frequencies as
they are scanned.
b) To exit Environment Scan, turn the SETUP control CW or CCW. The ">EXIT<" option will appear on the display
and start flashing.
4. Once the scan has reached the Stop frequency, the scan is automatically stopped and the message "READY" ap-
pears on the display.
5. To view the first item on the scan list, press the SETUP control briefly*. To scroll through the other items, turn the
SETUP control CW or CCW.
An interference source can be a single frequency as in example 1 or a frequency band as in example 2 below. The
RF meter on the display indicates the noise level of the scanned frequency or band.
Example 1: A noise level of -90 dB has been found on the receiving frequency of 762 MHz.
Example 2: A max. noise level of -80 dB has been found in the 764 MHz to 767 MHz band.
The last item on the scan list is the "EXIT" option.
6. To scroll through the list again, turn the SETUP control CW or CCW.
To return to the Environment Scan menu, press the SETUP control briefly.
• You can interrupt the scan at any time by pressing the SETUP control briefly. If you do, the message "PAUSED"
will appear on the display.
• To view the scan list, press the SETUP control briefly. You can scroll through the items on the list by turning the SETUP
control CW or CCW.
• Press the SETUP control briefly. The display will offer the "CONT" option.
• To resume the scan, press the SETUP control briefly.
• If Environment Scan has found no interference frequencies, the message "CLEAN" will appear on the display. Turn
the SETUP control CW and select "CONT" to continue the scan or "EXIT" to return to the Environment Scan menu.
If the scan list is full before the Stop frequency has been reached, the scan will be stopped automatically and the mes-
sage "OVFL" will appear on the display.
• To view the the scan list, press the SETUP control briefly. You can scroll through the items on the list by turning the
SETUP control CW or CCW.
• Press the SETUP control briefly. The display will offer the "CONT" option.
• Press the SETUP control briefly again. The scan list will be erased and the scan resumed.
1. Activate the Rehearsal function ("RHSL / REHEAR -> >START< -> RECORD") on the receiver referring to
section 3.9.1 below.
2. Move the transmitter around the area where you will use the system to check the area for "dead spots", i.e., places
where the field strength seems to drop and reception deteriorates.
If you find any dead spots, try to eliminate them by repositioning the receiver. If this does not help, avoid the dead
spots.
3. If the received signal is noisy, set the squelch threshold to a level where the noise will stop.
• Never set the squelch threshold any higher than absolutely necessary. The higher the squelch threshold,
the lower the sensitivity of the receiver and thus the usable range between transmitter and receiver.
SR 4500
3 Setting Up
3.8.6 Finding
Interference Frequencies
Note:
* If Environment Scan has found no in-
terference frequencies, the message
"CLEAN" will appear on the display.
• Press SETUP briefly.
• Turn SETUP CW to bring up "EXIT".
• Press SETUP briefly.
Interrupting the scan:
Memory overflow:

3.9 Before the Soundcheck

See also section 3.9.2.
L
The receiver will return to the Envi-
ronment Scan menu.
Important!
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