Instruction manual

ACU-1000 Operations Manual
Interoperability Now 4-13
The DSP-2 module includes an Audio Equalization feature that can either boost or roll off the
high end of the RX audio spectrum. This adjustment can compensate for poor RX audio
quality. Follow the procedure below to determine the proper Audio Equalization Setting.
Audio Equalization Procedure
The best way is to listen to the received audio in the HSP handset (not the HSP speaker, unless
a high-quality external speaker is connected).
• Monitor the RX Audio in the HSP handset.
• If the audio sounds like it lacks treble, the high frequencies can be increased (boost).
• If the signal sounds too bright or harsh, the high frequencies can be attenuated (cut).
• There are 3 steps of boost and 3 steps of cut plus the default flat setting. Move the
adjustment 1 step at a time and recheck for best sound.
4.9 Unintended Consequences
4.9.1 Unwanted Connections
The primary cause of unwanted connections that were not initiated by the operator or
authorized user is DTMF received via the radio channels connected to the ACU-1000. It is
possible that legitimate users are using DTMF for selective call, paging, or other functions
within their own system and the sequence of numbers accidentally corresponds to an ACU-
1000 command. DTMF can also be received as a result of intermodulation or other co-channel
interference. In many cases, legitimate users of the system will be unaware that the use of their
DTMF keypads are causing problems in the ACU-1000 system.
It is strongly recommended that all of the modules in the ACU-1000 that have a DTMF decoder
function be set to “DTMF disable.”
If it is essential for field personnel to have the ability to control the system via DTMF over
radio, then careful use and assignment of security levels and passwords should provide a
measure of protection.