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FUNCTIONAL DESCRIPTION
(continued)
Mute
The sound mute function is available as a toggle
command fromall commandsources.
There are other commands and functions during
which the sound is muted :
- FB/sync. coincidence - If there is no FB/sync.
coincidence under any conditions the sound is
muted.
- Startup reset- thesoundismutedforapprox.1.7
seconds.
- Program change - the sound is muted for 0.6
seconds on any program change ; direct, 1 * +
0-9 program (only after the second keystroke),
±
10 (decade)& Memory sequenceup/downcon-
tinuousor single keystrokes.
- Standby& Offstates - the soundis muted.
- Band sequence- same as programchange.
The sound is demuted under the following condi-
tions :
- When the mute command is received from any
source.
- When thedeviceiscommandedOnfromstandby
of Off, i.e. if the device was muted when the
standby command was issued then when On is
commandedit will always start up with the sound
demuted after the reset and settling period of
approx.17 seconds.
- Volume up - if volume up is commanded whilst
the soundis muted then the volume will increase
from zero.
- Volume down - if volume down is commanded
whilst the sound ismuted thenthere is no effect.
- Any program change - the sound is NOT de-
muted.
Momentary On Switch
Provision is made for a momentary switch con-
nectedbetweentheh+i pinandgroundto forcethe
M494 to makePower on andStart up resets auto-
matically so that the device attains the On state
immediately.
Theconditionof theh+ipinislatchedafterthereset
period of 110ms. Therefore the period of switch
contactclosure should be a min. of 120ms.
Figures.11 & 12 respectivelyshow in flowdiagram
form the twomethods for storinga station: pretun-
ing program selection and post tuning program
selection. Figures. 13, 14 & 15 show the select
programme subroutine for Figures. 11 & 12 for
either 16programoptionor20 programoptionwith
1 * or
±
10 (decade modes).
M494
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