Advanced Functions; Finding Interference Frequencies; Setting The Squelch Threshold; Hearing Protection Limiter - AKG PR4500 User Instructions

4 Advanced Functions

Finding Interference
Frequencies
("Field Scan" function)
Refer to fig. A6 in he Appendix.
Interrupting the scan:
Memory overflow:
Setting the
Squelch Threshold
Refer to fig. A7 in the Appendix.
Note
Hearing Protection
Limiter
Refer to fig. A8 in the Appendix.
30
In addition to the basic functions described in section 3 above, the receiver provides a se-
ries of advanced functions.
The Field Scan function automatically searches the receiver's entire frequency band for in-
terference frequencies.
The frequency spacing for the automatic scan is 100 kHz. Any frequency whose field strength
exceeds the factory-set fixed threshold is defined as an interference frequency and saved
in a scan list. Once the can is completed, you can retrieve the scan list.
The receiver can store a maximum of seven interference frequencies or three interference
ranges with their upper and lower frequency limits. As soon as the end of the examined fre-
quency range (Stop frequency) is reached or the scan list is full, the scan will stop auto-
matically.
1. In SETUP mode, turn the setup control up or down to call up the "FIELD" screen.
2. Press the setup control briefly.
3. To start the scan, select "RUN"; to return to the "FIELD" screen, select "ESCAPE".
4. During the scan, the audio output is muted and the display indicates the frequencies in
MHz as they are scanned.
5. Once the scan has reached the Stop frequency, the scan stops automatically and the
message "READY" appears on the display. If no interference frequencies were found, the
display will change to "CLEAN".
5. 6o scroll through the scan list, press the setup control briefly and turn the setup control
up briefly.
The last interference frequency is followed by the "ESCAPE" option (see step 2 above).
• You can interrupt the scan at any time by pressing the setup control briefly. The mes-
sage "PAUSE" will appear on the display.
1. To scroll through the scan list, press the setup control briefly and turn the setup control
up briefly.
The last interference frequency is followed by the "CONT." option.
2. To resume the scan, press the setup control briefly. The receiver will scan the rest of the
frequency band.
• To stop the scan, turn the setup control up briefly. This will bring up the "ESCAPE" op-
tion.
If the scan list is full before the Stop frequency has been reached, the scan will stop auto-
matically and the display will change to "FULL".
• Follow steps 1 through 4 in the paragraph on "Interrupting the scan" above.
• You can set the squelch threshold from -100 dBm to -82 dBm in 6-dB increments
(-100/-94/-88/-82).
• Make sure never to set the squelch threshold any higher than absolutely necessary. The
higher the squelch threshold (-100 dB = min., -86sdB = max.), the shorter the usable
range between transmitter and receiver.
The hearing protection limiter places an absolute ceiling on the HP OUT headphones output
level. Please note that the actual sound pressure at the ears will depend on the type of head-
phones used.
1. You can switch the limiter "ON" and "OFF".