Busy Channel Lockout

MAXON

SP-300 HAND HELD

A priority channel can be selected while programming the radio. A priority channel is a channel that can be periodi- cally checked or looked back to while receiving on any chan- nel in the scan list, or in normal operation. It can also be selected for all transmissions during scan mode.

If this feature is enabled, the unit will not transmit when a carrier is present. A beep tone will sound when the PTT is depressed.

To transmit on a channel in the scan list, the channel selector must be placed on the channel that the transmission is to be made on. As a system programmable option, it is possible to transmit on a scanned channel while the channel selector is on the scan list channel. This is the “Normal Scan TX” option. If this option is enabled the PTT can be pushed dur- ing the scan wait time and the transmission will be on the channel that was just activated. If this option is disabled, the transmission will be on the priority channel (if there is no priority channel programmed the transmission will be inhib- ited and out-of-lock indicator will be issued).

Any channel, whether it is in the scan list or not, can be des- ignated as a look back channel. When a channel is desig- nated as a look back channel, and the channel is selected, the radio will periodically look back to the priority channel dur- ing reception on the selected channel. The radio does not require a scan list to be entered in order to use this function, however, the radio MUST have a priority channel selected for the function to work.

•NOTE: The programmer must disallow the program- ming of a channel as a look back channel if no priority channel was selected.

The channel scan speed is system programmable in a range of 50 milliseconds to 2 seconds in 10 millisecond incre- ments. The default value is 100 milliseconds.

Scan Delay Time

Scan delay time is system programmable. The scan delay is the time the unit remains on a scanned channel, after receiv- ing or transmitting on that channel. The time is programma- ble from 1 to 10 in 1 second increments. The default value is 4 seconds.

The scan delay time will be reset each time the receive chan- nel is active and each time the PTT is pushed on that chan- nel. As long as the conversation continues on the channel, the receiver or the transmitter is active before the scan delay time expires, the unit will not resume scanning.

As a programmable option, the LED on the top panel of the unit will flash at the scan rate while in the scan mode. If the “LED scan indication” is programmed to enable the LED will flash. If it is programmed to disable, the LED will not flash.

Marked Idle Enable

If this function is enabled, the unit will transmit provided that the correct programmed CTCSS tone or DCS code has been decoded. This function is essential for repeater opera- tion.

Normal/Inverted DCS

This function is selected by channel during programming of the radio. During programming of each channel of the radio, a selective signaling option for TX and RX is selected. When the DCS signaling option is elected, it can be selected as either normal or inverted. The selection can be made dif- ferently for TX and RX.

Standard/Non-Standard CTCSS

When programming a channel with CTCSS, any frequency from 55 to 250 Hz can be selected in 0.1 Hz increments. The radio is capable of encoding and decoding two non-standard CTCSS tones.

Transmit Time-Out-Timer (TOT)/TX Inhibit

The time-out-timer is system programmable for 10 seconds to 990 seconds, in 10 second increments and can also be selected as disabled. The addition to this feature is a pro- grammable lock-out-timer that inhibits the radio transmitter for a specified time after the time-out time expires.

When the time-out-timer function is enabled, and the TX inhibit function is disabled, the radio will transmit after the time-out-timer has expired and the PTT button is released and depressed again. With the TOT and TX inhibit, the radio will not transmit after the time-out has expired, even if the PTT is released and depressed again. Transmission will not be allowed until the TX inhibit time has expired. TX inhibit time is system programmable from 5 to 60 seconds in 5 second increments. The radio will beep one time, 5 sec- onds before the TOT time expires. This will indicate to the user that the transmitter is about to be locked out. If the PTT is released and depressed again anytime before the TOT has expired, the TOT time will be reset. If the beep tone enable/ disable is set to disable, the one beep will not be issued. The radio will beep 4 times when the TOT time expires. After the TX inhibit time passes, the radio will beep one final time.

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May 2001