Velleman ALN006 - Manual (Page 14)

11
English
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2 Only one user at a time can talk during radio communications.
Therefore, it is important not to transmit when you are receiving a
communication and use the transmission mode sparingly to allow
other users to use the feature.
2 Transmission consumes a significant amount of energy and
should therefore be used sparingly to prolong the battery life.
Alternatively, it is also possible to select a low transmission
power.
2 If you are unable to contact a station that you have no problems in
receiving, the station may be using CTCSS tones or DCS codes
(O 5.8).
5.7 Busy channel lockout
The BCLO and TOT functions are disabled by default.
If BCLO has been enabled and the channel is busy, the selection of
PTT or CALL will have no effect and the radio will issue an error beep.
As soon as the channel is free, PTT and CALL shall automatically
resume ordinary operation.
5.7.a Transmission timer (TOT)
The HP450 2A radio can be programmed with a transmission timer
that temporarily blocks transmission if the radio has been used
beyond the maximum time permitted.
The radio is forced in reception mode if it continues transmitting
after the preset timer threshold has been reached. To restart the
transmission, it is sufficient to release and then press again the
PTT.
5.8 Operating modes (open or restricted traffic)
HP450 2A can be used in two modes:
Mode name: default
setting
Comments
Open traffic
(without CTCSS/
DCS)
From channel
1 to 8
Guarantees maximum
compatibility with the devices of
other manufacturers. However, if
the channel you are using is used
also by other parties, you will also
receive their communications.
Restricted traffic
(with CTCSS/
DCS)
From channel 9
onwards (with
several CTCSS
tones or DCS
codes)
CTCSS and DCS tones are
similar to access codes and
enable the radio to communicate
only with the parties that use the
same frequency or have set the
same code.
2 For information on how to change the CTCSS tone or DCS code
of a channel programmed in restricted traffic mode, see O 5.9.
2 The restricted traffic mode enables several radios to use the same
radio frequency. However, if several parties (for example a user
of group A and a user of group B) simultaneously use the same
channel for transmission purposes, interference may occur. For
this reason, it is advisable not to transmit if the radio signals that
the channel is busy although there are no communications.
2 The restricted traffic mode does not guarantee the privacy of
communications. In this mode it in fact possible to listen also
to parties that use CTCSS tones/DCS codes, although it is not
possible to call them because they would not be able to receive the