3. Benefit-Risk Balance
3.7. Benefit-risk assessment and discussion
Normal single channel operations can be performed from FIX radio mode. Channels which have not been programmed will contain a default setting that will display 2.0 MHz. When FIX radio mode is selected, the three letter designator (FIX) will be displayed on the top row of the LCD in the preset screen.
3.17.1 Select FIX Radio Mode
To select fix radio mode, press [MODE] until FIX appears. Press [ENT] to select.
3.17.2 Temporarily Select Different Channel Preset
Changes can be made while operating in FIX radio mode without reprogramming the AN/PRC-150(C). This includes operating frequency, squelch, transmitter power levels, modulation, encryption key, and voice.
Fixed frequency channel preset numbers can be selected from the channel screen, either by scrolling channel numbers, or by entering a channel number via the numeric keypad. Changes made in this manner are temporary and are only active until a different system preset is selected or the AN/PRC-150(C) power is cycled. Selectable channel range is 000 to 199.
Perform the following procedure to change channel preset:
a. To change settings, use the and keys to scroll to the CHAN setting.
b. Press [ENT] and enter the new channel number from the keypad or use to scroll through channels.
c. Press [ENT] to accept changes.
NOTE
Whenever the preprogrammed parameter changes, the radio places a < > around the system preset name on the KDU.
(Does not apply to MANUAL preset.) 3.17.3 Change Manual Channel 000
Channel number 000 is the manual channel. This is the only channel whose settings can be changed from the channel screen without going into the program. Perform the following procedure to change manual channel settings:
a. From the preset screen, press to display the channel preset screen.
b. Press until the channel number (CH###) is highlighted and press [ENT].
c. Press [0][0][0] to select the manual channel and press [ENT].
d. Press until the receive frequency (R) is highlighted and press [ENT].
NOTE
An alternate method to Step e is to not press [ENT] and use
and
keys to scroll the digit, then use to scroll the digit up or down. Press [ENT] when finished.e. Enter a new receive frequency using the keypad and press [ENT]. The transmit frequency automatically defaults to the receive frequency at this point.
f. Enter a new transmit frequency (if different from the receive frequency) using the keypad and press [ENT]. To keep the transmit frequency the same as the receive frequency, press [ENT] without entering a new transmit frequency.
g. Press until the modulation (MOD) setting is highlighted. Using the keys, scroll to the desired setting (USB, LSB, AME, CW, FM) and press [ENT]. A change in modulation choice may revert back to the original modulation if change incompatible with selected encryption or modem preset.
h. Press until the Automatic Gain Control (AGC) rate is highlighted. Use the keys to scroll to the
i. Press to return to the system preset screen.
3.17.4 SSB Scan - Capabilities and Limitations
SSB Scan is used to scan multiple FIX channels that have been programmed into the AN/PRC-150(C). Each channel must be individually enabled to allow inclusion in the SSB SCAN list. (Refer to Paragraph 4.7.) SSB scan stops scanning when an incoming signal is strong enough to break the programmed squelch level in the AN/PRC-150(C).
See Figure 3-10. SSB Scan limitations consist of the following:
•
SSB Scan is only functional in PT.•
All channels (0-199, inclusive) can be programmed for SSB SCAN.•
The frequency range for SSB scan channels varies as shown in Table 3-8.•
Valid modulations for SSB SCAN are USB, LSB, and FM.NOTE
The 125 W and 400 W PAs are not specified for FM.
•
Channels are scanned in ascending order by channel number, and will display on the channel screen.3.17.5 Enable SSB Scan
To enable/disable SSB scan, perform the following:
a. Choose OPT>SCAN>ENABLE SSB SCAN menu choices. Current SSB Scan setting is displayed.
b. Use the to scroll to the desired on or off setting and press [ENT].
c. To exit, press [CLR] several times or press [OPT].
3.17.6 Start/Stop SSB Scan Press [CLR] to start or stop SSB scan.
NOTE
If no channels have been SSB scan enabled, the radio cannot start an SSB scan and will display NO CHANNELS TO SCAN.
Table 3-8. Frequency Ranges for SSB Channels
Configuration Frequency Range (MHz)
With no external Power Amplifier (PA) 1.6000 to 59.9999, inclusive With external 20 W PA 1.6000 to 59.9999, inclusive With external 125 W PA 1.6000 to 29.9999, inclusive With external 150 W PA 1.6000 to 59.9999, inclusive With external 400 W PA 1.6000 to 29.9999, inclusive
3.17.7 Hail a Hopnet
Hailing permits a station in FIX radio mode to alert other net stations that are in HOP radio mode that a FIX station wishes to communicate. Channels can be programmed to allow a non-hopping radio to communicate with a hopping radio. Up to ten (10) FIX channels (001 - 010) can be designated for hail operation as to match operational frequency range of HOP nets, which permits a spread of frequencies on the propagation range for planned links. While in the HOP radio mode, the radio monitors the preprogrammed hailing frequencies for any radios in FIX radio mode that want to communicate.
When a radio in HOP radio mode receives a hail, a HAILED status displays on the channel and system preset on which the hail is occurring. The hailed station must then leave the HOP radio mode and select the FIX radio mode of operation using the same hailing channel on which the hail took place. At this time, the two stations can coordinate wristwatch TOD, if needed, and coordinate net entry. Hailing permits a station to alert other net stations that may be in HOP radio mode, that a station in FIX radio mode wishes to communicate.
NOTE
Hail TX must be enabled during channel programming. Only channels 001 to 010 can be set to be used as hailing channels.If the channel has not been programmed for hail, the AN/PRC-150(C) displays HAIL NOT ALLOWED. Refer to
Paragraph 4.7.
Perform the following procedure to hail a Hopnet:
a. To perform a hail, ensure the AN/PRC-150(C) is in FIX radio mode, and that the channel has been set to YES under the HAIL TX programming menu. Refer to Paragraph 4.7.
b. Select the designated hailing radio preset using the [PRE] key. Normally a frequency is selected that is near the frequencies of operation of the hopping net that will be hailed.
c. Press [CALL]. The AN/PRC-150(C) will display a “SEND HAIL” message.
d. Use the to scroll to the desired yes or no setting. Select YES and press [ENT] for confirmation to send hail.
e. The AN/PRC-150(C) will display HAIL IN PROGRESS, and then HAIL COMPLETE when the hail has been sent. Press [ENT] to return to the preset screen.
F-0103-4100-0015-A
Figure 3-10. Scan Option Menu Tree
ENABLE SSB SCAN NO
YES SCAN*
STU OPT
7
* FIX ONLY
NOTE
At the receiving radio, the user needs to press [ENT] to respond to the hail. Once the hail has been responded to, the receiving radio will switch to FIX. Therefore, the radio will need to be switched back to HOP to continue with frequency hopping operation.
NOTE
When someone from the hopping net contacts your station, coordinate to receive a time sync in order to enter the hopping net. Ensure radio TOD is within +/- 90 seconds of the station sending the time sync.