Use; Volume Adjustment - JRC Alphatron Marine AlphaAnnounce Installation And Operation Manual

3.4 Use

Front panel buttons are all locked type buttons and they are activated by pressing button down. Buttons are prioritized as
following:
Activating ALL CALL button will stop all alarm signals but audio signal won't be heard until PTT on microphone is
pressed.

3.5 Volume Adjustment

Message and microphone audio volume levels are set in optimal levels as default but if levels needs to be adjusted it is
done with two trimmers inside the unit. See Figure 7: Volume adjustment on page 32
Trimmer R7 is for adjusting message volume levels.
Trimmer R8 is for adjusting microphone volume levels.
31 | AlphaAnnounce Backup