Unfortunately the manual is not entirley correct, and certainly incomplete, when it comes to adjusting the GALA funtions of the Delta radio.

Firstly, following the above instructions (pressing and holding the "TP" button while switching the radio on) actually brings up a display showing the text "GALA". This sets control of the vehicle speeds at which the volume is automatically adjusted. Move the indicator bar using the up & down buttons to the left of the volume control. Moving the bar all the way to the left causes the volume to increase at lower speeds (recommended by author). Make adjustments as required and store by pressing the two buttons to the left of the rotary volume knob at the same time (the text "GALA" will be extinguished).

Now, pressing the "TP" button again allows the setting of the amount of volume change made by the GALA system. The display will change to "VOL" Again move the indicator bar using the buttons as above - bar to the right causes a greater volume change as speed increases (recommended). Adjust as required and again press the two buttons to the left of the rotary volume knob at the same time to store ("VOL" will be extinguished). Turn the radio off and on again to resume normal radio operation.

If both these adjustments are set with their bars at the leftmost positions, the volume of the radio will be boosted by 1dB at 30mph, 2dB at 50mph and 3dB at 60mph (possibly more at even higher speeds - I haven't checked!).

Lastly, you can get a visual check of the effect of your adjustments by turning off the radio, then pressing and holding the channel "2" button while switching the radio on. The display "GALA" will then be shown along with the volume level adjustment in dB (eg "GALA 0DB" when the vehicle is at rest). You will see the display change as your vehicle speed increases and decreases. Turn the radio off & on again to remove this GALA display.