User Manual
LMb
LECTROSONICS, INC.
8
Selecting Programmable Switch Functions
The programmable switch on the top panel can be con-
figured using the menu to provide several functions:
• Power - turns the power on and off
• Mute - mutes the audio when switched on
• TalkBk (talkback) - redirects the audio to a different 
output channel on the receiver (with receivers that 
offer this function)
• (none) - disables the switch
Gain
Freq.
ProgSw
Compat
ProgSw
Power
ProgSw
 Mute
ProgSw
TalkBk
ProgSw
(none)
Use the   and   
arrow buttons to 
select the desired 
function or disable 
the switch
NOTE: The programmable switch will continue 
to operate whether or not keypad changes are 
locked.
Main Window Indicators
The Main Window displays the block number, Standby 
or Operating mode, operating frequency, audio level, 
battery status and programmable switch function. When 
the frequency step size is set at 100 kHz, the LCD will 
look like the following.
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494.500
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0
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MUTE
Block number
Frequency (MHz)
Frequency 
(hex setting)
Operating mode
Battery status
Programmable 
switch function
Audio level
When the frequency step size is set to 25 kHz, the hex 
number is smaller and may include a fraction.
Note that the 
frequency has 
increased by 25 
kHz from the upper 
example.
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MUTE
1
4
51
Fraction
1/4 = .025 MHz
1/2 = .050 MHz
3/4 = .075 MHz
Changing the step size never changes the frequency. 
It only changes the way the user interface works. If the 
frequency is set to a fractional increment between even 
100 kHz steps and the step size is changed to 100 kHz, 
the hex code will be replaced by two asterisks on the 
main screen and the frequency screen.
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MUTE
Freq.
b 19
494.525
Frequency set to fractional 25 kHz step, 
but step size changed to 100 kHz.
If the programmable switch function is set for Mute, the 
Main Window will indicate that the function is enabled.
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MUTE
Mute function 
enabled but 
not active
When the switch is turned on, the mute icon appear-
ance will change, the word MUTE will blink at the bot-
tom of the display, and the power/function LED will blink 
blue.
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BAT
494.500
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MUTE
<–MUTE–>
51
Main Window will blink 
the word MUTE when 
the audio is muted
Top Panel LED will 
blink blue when the 
audio is muted
If the programmable switch function is set for Talkback, 
the Main Window will indicate that the function is en-
abled but not active.
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TB
51
Talkback 
function is 
enabled but 
not active
When the programmable switch is turned on, the talk-
back icon appearance will change and the power/func-
tion LED will glow blue.
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BAT
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TB
51
The TB icon will 
change when 
Talkback is active
Top Panel LED will 
glow blue when 
Talkback is active










