Call guard squelch, Miscellaneous, Supervisory tones – EFJohnson LTR-Net 002-9803-601 User Manual
Page 47

MISCELLANEOUS
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Talk-around is then automatically selected when one of these
groups is selected. There is no special talk-around option switch or 
indicator. However, the group alpha tag on the lower line of the 
display may be used to indicate groups programmed for this feature. 
Talk-around is not available on LTR-Net and LTR systems.
Call Guard Squelch
The Call Guard squelch feature eliminates distracting messages
intended for others using the channel. This is done by using a 
subaudible tone or digital code to control the squelch. This tone or 
code is unique to a user or a group on that channel. It is transmitted 
with the voice signal but is not heard because it is in the subaudible 
range and attenuated by a filter. Call Guard squelch can be 
programmed on each conventional group. LTR-Net and LTR opera-
tion uses ID codes to perform a similar function.
MISCELLANEOUS
Supervisory Tones
The following tones are heard at various times when operating
this transceiver. Some or all of these tones can be disabled by the 
TONES menu parameter or programming. Refer to “Tone Select” on 
page 26 for more information.
Busy Tone
This tone is similar to the standard telephone busy tone, and it
indicates that the radio system is currently busy. The display also 
indicates “BUSY” while this tone is sounding. Repeated access 
attempts are made while the PTT switch pressed with this tone 
sounding. Therefore, it is not necessary to release the PTT switch to 
access the system. This tone sounds only with LTR-Net and LTR 
calls.
