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VHF radio (Simrad® RT64 as prototype)
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Home page
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Features :
display and button backlighting
user channel
channel transmit power 1 or 25W
dual watch and tri-watch modes
scan
scan of selected channels
squelch, volume and channel rotary controls
fistmike with PTT (push-to-talk) and select channel buttons
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Function
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How to implement
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switch on
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rotate volume knob clockwise.
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switch off
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rotate volume knob fully counterclockwise.
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backlighting
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press [F] button to switch to the "second function" mode. Successively
click [F] to change backlighting level.
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channel selection
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rotate channel knob clockwise to scroll VHF channels up, counterclockwise
to scroll down. Also use the upper and lower buttons of the
fistmike.
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changing channel transmission power
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press [1/25] button.
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dual watch
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dual watch can be started by pressing [D/W]. Then, currently
selected channel and the priority channel will enter the scan
sequence. In case of priority channel currently selected,
dual watch is not possible and [DW] switches to previously
selected (not priority) channel. Stop dual watch by pressing [D/W],
[16] or rotate channel knob counterclockwise.
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tri-watch
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this scan mode is similar to dual watch, but the three channels
are scanned instead of two, namely current channel,
priority channel (16) and user channel. Start tri-watch by
holding down [D/W] for 2 seconds. Stop tri-watch by pressing [D/W],
[16] or rotate channel knob counterclockwise.
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selecting user channel
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user channel used in tri-watch scan can be selected by the
following procedure. Select the channel, press [F], then press
and hold [16]. After 2 seconds the new user channel will be selected.
If user channel is currently selected, the display shows "USE" sign.
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scan (all channels)
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all (not inhibited) channels are scanned one by one until a signal
above the current squelch level is detected. Start scan by pressing
[SCN] button. Stop scan by pressing [SCN] again, [16], or turning the
channel knob counterclockwise.
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excluding channels from scan sequence
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if a channel has a lot of interference noise, it would cause scans
lock onto this channel. To exclude such a channel from scan sequence,
a channel can be inhibited. Press [F] then [D/W] to inhibit the
selected channel (the display will show INH ofr such channels), or
press [F] plus [D/W] again to enable a currently selected channel
(the display shows ENA).
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scan memory (selected channels)
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a set of selected channels can be specified and this sequence
scanned. To add a new channel into the scan memory, select a channel
and press [F] then [1/25]. If such channel is already in memory,
it will be deleted. Start scan by pressing [F] plus [SCN] button.
Stop scan by pressing [SCN] again, [16], or turning the
channel knob counterclockwise.
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setting squelch level
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SQL knob is used to set squelch level (receiver muting threshold) to
suppress interference noise. Note that during a scan the noise may
lock a channel, so usually scanning can proceed with squelch
level increased to a certain value.
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transmitting
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stop all scans, set a channel and press the PTT (Push-To-Talk)
button on the microphone. Hold down the button while you speak.
To be heard from another ship equipped with another VHF radio,
you must be not farther away than roughly 20NM, and the receiving
VHF radio must hold the receiving (RX) frequency equal to
transmitting (TX) frequency of the transmitting radio. Specifically,
it means that the communication is OK when the two parties
communicate on the same SIMPLEX (equal TX and RX frequencies)
VHF working channel.
Communications between ships are not possible on duplex channels,
which have different RX and TX frequencies.
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priority channel
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priority channel (16) is used for transmitting distress messages only.
To quickly set this channel, press [16]. Routine communications are
prohibited on this channel.
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© Copyright 2007..2009 MI Simulators
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