UNITED STATES ARMY AVIATION WARFIGHTING CENTER FORT RUCKER, ALABAMA JUNE 2011

Transcription

1 UNITED STATES ARMY AVIATION WARFIGHTING CENTER FORT RUCKER, ALABAMA JUNE 2011 STUDENT HANDOUT TITLE: AH-64D High Frequency Radio Communication (LOT 13) FILE NUMBER: Proponent For This Student Handout Is: COMMANDER, 110 TH AVIATION BRIGADE ATTN: ATZQ-ATB-AD Fort Rucker, Alabama FOREIGN DISCLOSURE STATEMENT: This product/publication has been reviewed by the product developers in coordination with the USAAWC Foreign Disclosure Officer, Fort Rucker, AL foreign disclosure authority. This product is releasable to students from all requesting foreign countries without restrictions. D-3

2 Terminal Learning Objective: At the completion of this lesson, you (the student) will: ACTION: Identify components and perform operating procedures for the AH-64D High Frequency (HF) Communications Radio Subsystem CONDITIONS: In a classroom environment, given an AH-64D Operator's Manual (TM ) and the Aircrew Training Manual (TC 1-251), and the Student Handout. STANDARD: In accordance with TM D-4

3 A. ENABLING LEARNING OBJECTIVE 1 ACTION: Identify the purpose and capability of the AH-64D HF Radio Subsystem CONDITIONS: Given a written test without the use of student notes or references. STANDARD: In accordance with TM Learning Step/Activity 1 Identify the purpose and capability of the AH-64D High Frequency Radio Sub-System Figure 1. a. HF Radio Operations HF Radio Operations. (1) The ARC-220 HF radio provides the Apache Longbow aircrew with a fifth radio for Line Of Sight (LOS) and extended Non Line Of Sight (NLOS) communication range capability for long-range (greater than 300 nautical miles) dissemination of battlefield information. (2) The ARC-220 radio provides HF communication in the following modes: (a) (b) (c) Manual frequency tuning Preset channel tuning on preprogrammed frequencies Automatic Link Establishment (ALE) automatic frequency scanning of predetermined frequencies for selection of the best frequency for communication D-5

4 (d) (e) Electronic Counter Counter Measures (ECCM) frequency hopping (anti-jam) of predetermined frequencies in a pseudo random order to reduce the possibility of jamming the communications link and/or direction finding Emergency a preprogrammed configuration of the ARC-220 radio used in case of an emergency (3) The ARC-220 radio does not use the IDM system when transmitting or receiving data messages. It has its own internal data modem. When operating in noisy environments, data transmissions can often be received when voice messages cannot. (4) Positioning and target data can be transmitted in this manner. Up to 25 preprogrammed data messages can be stored for future transmission, and up to 10 received data messages can be stored and retransmitted. The received HF data messages are retrieved or viewed on the MSG REC page. (5) To employ the HF radio properly on the battlefield, the following must occur: (a) (b) (c) (d) (e) A frequency schedule is created and used within the unit for HF operations. An HF communication network is created in AMPS and loaded to the DTC. Crews ensure that the DTU HF information has been properly loaded into the aircraft. The HF radio is initialized and setup correctly. Crews select the most effective HF radio mode (i.e.: ECCM versus PRESET). D-6

5 Figure 2. b. HF Radio Wave Propagation HF Radio Wave Propagation. (1) Activity on the sun can have a wide-ranging effect on the earth and its atmosphere including the disruption of communication. Radiation from the sun removes electrons from atoms in the upper regions of the earth's atmosphere, forming the ionosphere. The existence of the ionosphere allows the use of HF radios as a means of communication over long distances. (2) HF (2-30 MHz) radio waves propagate as line-of-sight (direct) and sky waves (reflected). Sky waves use the ionosphere to extend the range of communication by reflecting the transmitted radio signals back toward the earth. Sky waves provide the longest geometric range possible (independent of transmitted power). (3) The reason is simple: assuming propagation in a straight line, if the signal reflects off something at a significant altitude the maximum range is extended. Usually straight-line distance is limited by the horizon (lineof-sight). A sky wave can extend the propagation path well beyond the visible horizon. (4) A HF signal transmitted from an aircraft or vehicle may travel some way through the ionosphere before being "reflected" back down towards the ground. This occurs due to the interaction between the HF signal and electrically charged particles in the ionosphere. The signal can then "bounce" off the ground back into the ionosphere, return to the earth again, and so on. D-7

6 (5) The distance a given HF signal can travel depends on the following factors: (a) (b) (c) (d) (e) (f) c. Frequency Spectrum Transmitter power Frequency Altitude of aircraft Take-off angle relative to the ground Atmospheric conditions through which the signal is traveling Simply increasing the transmitter power of a HF signal will not help if the frequency is too high for the distance required. Increasing the power may help if the frequency is too low, but using a higher, more suitable frequency is the best option. The highest frequency that can be used for reliable HF communications is known as the Maximum Usable Frequency (MUF). (1) For any given distance and time, there will be a certain range of HF frequencies that are more likely to provide successful communications; frequencies outside that range will work poorly or not at all. (2) The height of the ionosphere (reflecting height) fluctuates based on the time of day and the geographical area of operation. The higher the reflecting height, the greater the communications range (for a given angle of incidence). (3) There are many factors that must be considered when using HF radio communication and selecting the frequencies that will work best. (a) (b) (c) (d) (e) (f) The reflecting layer height goes up with the Sun (and back down), reaching a maximum at local noon. The ionosphere absorbs radio waves, having maximum absorption at lower frequencies and less as the frequency increases. Frequencies above a maximum value are not reflected at all and continue into space. Use the maximum frequency that will reflect (called maximum usable frequency or MUF). As the ionosphere reflecting height increases, the MUF also increases. Frequency Schedule 1) Change the frequency in use during the day to use the highest frequency that will reflect. 2) So highest frequencies are at local noon, lowest frequencies are at night. D-8

7 Figure 3. Near Vertical Incidence Sky (NVIS) Wave. d. Near Vertical Incidence Sky (NVIS) Wave (1) For many years, HF communication has been used extensively for long distance communications. There are two primary reasons HF has not been widely used for short-range communications. (a) (b) The first reason is that propagation variables of geographic location, solar activity, and signal fading make conventional HF radio operation crewmember intensive. In recent years, the problem of HF radio operation being crewmember intensive has been resolved by the introduction of the Automatic Link Establishment (ALE) function. ALE is the radio s ability to test selected frequencies to establish the best communication link with another HF radio platform. The second reason is a general confusion about HF radio wave propagation. HF ground waves are propagated along the surface of the earth out to a distance of approximately 60 miles (based on the altitude of the aircraft). After 60 miles, the signal becomes too weak to be usable. (2) As the operating frequency increases, ground wave signals are attenuated more, reducing the effective range. HF sky waves are radiated upward from the antenna and reflected back to the earth by the ionosphere. Sky waves provide the long distance communications capability. The confusion is that a skip zone of up to 90 miles exists where no usable signals can be reflected. The skip zone was thought to begin where the ground wave ends and end where the sky wave returns D-9

8 to the earth. The skip zone has been minimized on the Apache Longbow through the installation of a NVIS antenna. (3) The misconception of a skip zone has been replaced by an understanding of Near Vertical Incidence Sky (NVIS) wave propagation. With the installation of a HF NVIS antenna that provides a near vertical radiation angle (about 80 degrees from horizontal) and the selection of frequencies that do not penetrate the ionosphere, energy is reflected back to earth in an omni-directional pattern without a skip zone. NVIS links provide reliable communications up to approximately 190 miles, even in hilly or mountainous terrain not suitable for Line-Of-Sight (LOS) communications. (4) The frequency limitations for NVIS propagation are approximately: (a) (b) 2.0 to 4.0 MHz at night 4.0 to 8.0 MHz during the day (5) Frequencies higher than 8.0 MHz are not reflected back to earth by the ionosphere at NVIS radiation angles. Figure 4. e. HF Wave Attenuation HF Wave Attenuation. (1) Some factors that can affect normal LOS communication are range, transmitted power, and attenuation due to poor weather. D-10

9 (2) Other factors that can affect HF communication include the following: (a) (b) (c) (d) (e) Extreme Ultraviolet (EUV) radiation from the sun creates the ionosphere. EUV radiation arises from the bright and hot regions that overlie sunspots (areas of strong magnetic fields on the sun's surface). As the sun progresses through its eleven-year cycle of activity, the number and size of sunspots will vary, as will the level of EUV radiation. Changes to the ionosphere that result from this mean that conditions affecting the use of the HF radio will also change over the solar cycle. 1) At the low point of the solar cycle, only the lower frequency HF signals can be transmitted over a given distance. 2) At the peak of the cycle, the higher frequencies in the HF band can be transmitted over the same distance. Other factors important in determining the range of usable HF frequencies include: 1) Seasons 2) Time of day 3) Relative locations of the transmit and receive points Short-wave Fadeouts are short lived (up to two hours) disturbances, in which solar flare activity results in the absorption of lower frequency HF signals. These will only affect signals passing through the daylight ionosphere. Ionospheric Storms are large-scale changes in the chemical composition of the ionosphere resulting in changes to the MUF. Decreased MUFs restrict the frequencies available for use over a given distance. Ionospheric storms normally last for one to two days. D-11

10 CHECK ON LEARNING 1. What are the five HF radio modes of operation? ANSWER: 2. How many preprogrammed data messages can be stored in addition to the 10 received messages? ANSWER: 3. The HF radio reflects it signal of what atmospheric level? ANSWER: 4. The highest frequency that can be used for reliable HF communications is known as? ANSWER: 5. Ionospheric storms can interfere with HF radio frequencies for 1 to 2 days while Short-Wave Fadeouts can interfere with HF radio frequencies for how long? ANSWER: D-12

11 B. ENABLING LEARNING OBJECTIVE 2 ACTION: Describe Automatic Link Establishment (ALE) operations CONDITIONS: Given a written test without the use of student notes or references. STANDARD: In accordance with TM Learning Step/Activity 1 Learning Step / Activity Describe Automatic Link Establishment (ALE) operations a. ALE Operation Figure 5. ALE Theory. (1) In the past, a crewmember s knowledge of radio signal propagation and the ability to apply that knowledge to select usable HF frequencies were crucial to the success of conventional HF communications. Ask any HAM radio crewmember. Using conventional methods (single channel tuning), a HF crewmember can typically reach a distant station less than 30% of the time on the first try. (2) Using ALE, the success rate for first try connectivity is improved to nearly 90% with no special training or knowledge of HF signal propagation required by the crewmember. ALE improves HF communications quality and connectivity while reducing the crewmember tasks required to communicate under constantly changing propagation conditions. (3) ALE is a means of automatically establishing a common radio link between two or more HF stations. Radios using ALE still operate in the HF band and all characteristics of HF signal propagation apply. There D-13

12 are major differences between conventional HF and ALE HF communications. (a) (b) (c) Unlike conventional HF communications, ALE allows selective calling to other similarly equipped HF stations. ALE automatically chooses the best available frequency from a preprogrammed list of frequencies to make the call. All that needs to be known is the address (ALE Call Address) of the other ALE station(s) with which communications is desired. (4) Although the HF radio provides the capability to manually select a station address, the ARC-220 is normally preprogrammed as part of a data fill to include 20 preset ALE nets. A crewmember can quickly select a Call Address by selecting the appropriate preprogrammed address. Establishing ALE communications is similar to placing calls using a telephone. (a) (b) (c) A crewmember selects a station address and initiates a call. The ALE system automatically establishes a two-way communications link. The calling station s address is displayed for the receiving station to show who has placed the call (Caller ID). Once the link is established, the HF ALE operates the same as a conventional HF system. Figure 6. (5) ALE Scanning (a) ALE Scanning. During ALE operation, a net or scan list is continually scanned at a rate of two to five frequencies per second. A scan list is typically comprised of 5 to 10 preset frequencies throughout the D-14

13 HF band. During scanning, the ALE system listens for soundings and calls from other ALE stations. The receive audio is muted during scanning to reduce crewmember fatigue. Preferred Freq Figure 7. ALE Sounding and Link Quality Analysis (LQA). (6) ALE Sounding and Link Quality Analysis (LQA) (a) (b) (c) (d) Two ALE features, sounding and Link Quality Analysis (LQA) are used in the automatic frequency selection process. Each ALE station can be preprogrammed to periodically (automatically) sound (transmit short bursts of data) on each scanned frequency. Typically, a crewmember will choose to sound manually. Soundings contain the transmitting station s address. ALE stations receiving the signal use the soundings to rate the best frequency for them to call the transmitting station. ALE receiving stations assign the soundings a signal quality, known as an LQA value. The LQA value is stored in a database with the time, sounding station s address, and frequency on which the sounding is received. The LQA value is used to rank the frequencies for later calls to the sounding station s address. The higher the LQA value, the better the frequency. Crewmembers using ALE also have the capability to manually initiate a sounding at any time, which allows other stations LQA databases to be updated. Manual sounding is recommended every time a new net is selected or if a considerable change in range or elapsed time has occurred. D-15

14 (e) (7) ALE Call (a) (b) (c) (d) (e) (f) (g) When a transmission is made to another ALE station, the ALE system automatically picks the best frequency from the scan list in the net to support communications between the two stations. To initiate an ALE call, a crewmember selects the station address and keys (transmits) over the HF system. The ALE system reviews LQA values for the desired address (which represent near real-time propagation conditions). It establishes a data handshake between the two stations on the best available frequency. Once the two-way link is established, receive audio is restored and normal voice or data communications can begin. If a link attempt is not successful on the first frequency selected or if the frequency is busy, alternate frequencies are automatically selected. The call is repeated until one of the following occurs: 1) A link is established 2) All active frequencies are tried at least once 3) Call attempt is aborted by the crewmember To end an ALE call, select the ABORT button or set the SCAN/HOLD button to HOLD and then back to SCAN on the HF page. D-16

15 Figure 8. b. Station-to-Station Call ALE Call Addresses. (1) The station-to-station call (also called point-to-point or individual call) is the simplest form of an ALE call. (2) Station-to-station calls establish a two-way communications link between two individual ALE stations on a single automatically selected frequency. (3) Station-to-station calling is accomplished through a three-part handshake between the calling and receiving stations. The handshake sequence is automatic and begins when a crewmember initiates a station-to-station ALE call. (a) (b) (c) The calling station transmits a call. The receiving station transmits a response. The calling station transmits an acknowledgment to confirm the two-way communications capability. (4) The call, response, and acknowledgment are short Frequency Shift Key (FSK) transmissions. The transmissions identify the address of the station being called and the address of the calling station. Once the link is established, both stations are alerted that communications can begin. The station that placed the call should initiate the conversation. This prevents both stations from trying to transmit at the same time. (5) There are three types of addresses associated with station-to-station calls: (a) Self address - A Self Address is the transmitting ALE station s call sign. It serves as the calling station identifier. D-17

16 (b) (c) Call address - A Call Address is the Self Address of other stations with which communications are desired. Self addresses and other station addresses are preprogrammed into the ALE system on the AMPS. Floating address - When the calling station links with a station that is not preprogrammed into the other station address table, that station s address (referred to as a floating address) is automatically stored for future recall in the next available position within the OTHER call list which will be discussed in the MPD hierarchy section of this lesson. (6) Most ALE addresses consist of three alphanumeric characters, but addresses up to 15 characters in length can be used. A maximum of six characters is recommended. Figure 9. ALE Call Options c. OTHER ALE SPECIAL CALL OPTIONS (1) Besides station-to-station calls, automatic communication links can be established using any of the following ALE call options. The type of call used for a given address is determined by the data fill. (2) Differences between the ALE calls are based on how many stations are to be contacted and how those stations are to respond. All of the following calling options attempt to call a number of ALE stations with a single call on a single frequency. D-18

17 (3) Note that propagation might not support communications between the entire group. This is due to the differences in propagation conditions between multiple station locations. (a) (b) (c) Auto Call - An auto call allows a station to attempt a link with other stations within a network. The HF radio attempts to link to all stations within the selected net in a sequential manner. The HF radio continues to attempt a link until one of the receiving radios within the net replies and a link is established. This calling option is rarely used. All Call (Emergency) 1) An all call allows a station to call all ALE stations within a network. No response transmissions are expected from the other stations. The all call establishes a one-way communications path to many stations on one frequency. 2) All ALE stations receiving an all call stop scanning and listen for the transmission message without keying their transmitters. A practical application of an all call would be to broadcast an emergency message to as many stations as possible. There is no response expected or needed from those stations. Net Call (Star Net) - A net call establishes a communications path to several stations simultaneously. A net call allows a station to establish a call to a predefined group of stations with a single shared net address. It requires the receiving stations to respond, one at a time, in a predefined order. D-19

18 Figure 10. d. ALE Silent Operation ALE Silent Operation (1) ALE stations respond automatically to ALE calls without crewmember action as part of the automatic linking process. (2) During automatic sounding or automatic response to ALE calls, the ALE system transmits a response signal from the antenna. This often occurs without the crewmember s knowledge. (3) When a station does not want the ALE system to automatically transmit (sounding or automatic response), such as during radio silence, ALE systems use a receive-only (silent) state of operation. (4) In silent mode, the ALE system scans receive frequencies but does not respond to ALE calls or transmit soundings automatically. PTT is still active in silent state. NOTE: Silent operations should be considered for all FARP operations and when the tactical situation dictates it. e. ALE System Programming (1) The type of data preprogrammed (data fill) into the ALE system before use varies depending on the communications plan for the network. (a) (b) Simple ALE networks may only involve station-to-station ALE calls on a limited number of frequencies. Simple networks require a relatively simple data fill. Networks that are more complex require a relatively large data fill. D-20

19 (2) Regardless of the complexity of the communications net, there is a certain amount of data that must be loaded into each ALE system to allow it to operate efficiently with other ALE systems. (3) A network manager is typically responsible for configuring and managing the ALE network. The network manager assigns: (a) (b) (c) Station addresses Frequencies Other system parameters (4) These preprogrammed parameters determine the operational characteristics of the ALE system on a network-wide basis. Typically, the network manager uses a Data Transfer Unit (DTU) and/or Aviation Mission Planning System Station (AMPS) to create and download a data fill into each ALE system before operation. (5) Data fills can be loaded to the aircraft using the DTU or the Automated Net Control Device (ANCD). (6) A good DTU and/or ANCD load is essential for HF communication. If any parameters are missed from a data fill when loading the HF radio, HF communication is jeopardized. D-21

20 CHECK ON LEARNING 1. What HF mode has increased first try connectivity while reducing crewmember workload? ANSWER: 2. What two ALE features are used in the automatic frequency selection process? ANSWER: 3. What is the simplest form of ALE call? ANSWER: 4. The 3 types of addresses associated with station-to-station calls are? ANSWER: 5. What MODE should be considered for all FARP operations and whenever the Tactical situation dictates? ANSWER: D-22

21 C. ENABLING LEARNING OBJECTIVE 3 ACTION: Describe HF Radio Components CONDITIONS: Given a written test without the use of student notes or references. STANDARD: In Accordance With TM Learning Step/Activity 1 Describe HF Radio Components Figure 11. AN/ARC-220 (V) 2 HF Radio System Components. a. HF RADIO SYSTEM COMPONENTS (1) GENERAL - The HF radio set has been incorporated into the existing communication system, adding a fifth radio to the communication suite. (a) (b) The AN/ARC-220 (V) 2 HF radio set provides two-way HF Line- Of-Sight (LOS) and over the horizon non-line-of-sight (NLOS), air-to-air, and air-to-ground voice and data communications capability for the aircraft. The AH-64D HF radio system is comprised of the following remotely located components: 1) Receiver/Transmitter (R/T) 2) Power Amplifier Coupler (PAC) 3) Secure Voice Processor 4) Grounded Loop NLOS Towel Bar Antenna 5) Battery Box D-23

22 6) Dedicated Cooling Fan Figure 12. HF Receiver/Transmitter. (2) RT-1749/URC HF Receiver/Transmitter (R/T). The RT-1749/URC HF R/T provides transmission and reception capability to include analog voice and digital data communications. (a) (b) (c) (d) The HF radio is located in the left aft avionics bay. It is mounted behind the AN/AVR-2A (V) 1 Interface Unit Comparator (IUC) and AN/APR-39A (V) 1 digital processor on the top shelf. It is installed sideways, facing forward. The HF R/T receives and transmits signals in the to MHz band on any one of 280,000 frequencies, spaced in 100 Hz steps. The R/T provides simplex and half-duplex operation with the following emission modes: 1) Upper Side Band (USB) voice and data 2) Lower Side Band (LSB) voice and data 3) Amplitude Modulation Equivalent (AME) voice 4) Continuous Wave (CW) voice tone only for emergency Morse code transmissions The R/T uses a microprocessor to perform all the Automatic Link Establishment (ALE) and modem functions. The R/T internal power supply operates using 28 VDC primary power supplied by the Power Amplifier Coupler (PAC). While operating solely on battery power, the HF radio can receive while on the ground or in the air, and can be manually keyed for transmission but only while in the air. The ground inhibit function prevents the HF radio from transmitting while on the ground operating on battery power only. D-24

23 (e) (f) (g) (h) (i) Data fill, key fill, and data messages are stored in R/T Non- Volatile Memory (NVM). The R/T uses battery-backed static Random Access Memory (RAM) as its memory medium with power supplied from an external 6.0 to 24.0 VDC power source. This external battery source saves the data fill, key fill, and data messages when power is removed from the radio. Along with conventional HF communications, the AN/ARC-220 provides Automatic Link Establishment (ALE). This ALE capability simplifies HF radio operation and is similar to using a telephone to place calls. A crewmember selects a desired station address and initiates a call. The Digital Signal Processor (DSP) circuits within the radio generate the ALE data signals required to automatically establish a two-way communications link on the best available frequency. After a link is established, the crewmember is alerted that communications can begin. The HF radio is also capable of Electronic Counter Counter Measures (ECCM) operation. This ECCM capability is a frequency hopping (FH) technique used to combat the effects of communications jamming and direction finding attempts. The ARC-220 radio includes a data modem. When operating in noisy environments, data transmissions can often be received when voice messages cannot. Data messages can be used to transmit position and targeting data. Up to 25 preprogrammed data messages can be stored for future transmission. Up to 10 received data messages can also be stored and retransmitted. D-25

24 Figure 13. HF Power Amplifier/Coupler. (3) AM-7531/URC HF Power Amplifier/Coupler. The AM-7531/URC HF power amplifier/coupler provides the selected output power and the antenna coupling for the selected frequency during HF radio transmissions. The PAC is located in the pass-thru bay. It is installed in a mounting rack within the pass-thru bay and is mounted sideways, facing forward. (a) Power Amplifier. During transmit operation the power amplifier circuits amplify the 100 milliwatt RF input from the R/T to the selected power level. The PAC provides three output power levels: 1) Low 10 Watts (Average and Peak-to-Peak) 2) Medium 50 Watts (Average and Peak-to-Peak) 3) High 100 Watts (Average) and 175 Watts (Peak-to- Peak) NOTE: Peak-to-Peak refers to the maximum output wattage from low to high cycle (spikes) during a transmission. Average refers to the general rating of the radio signal output. (b) Antenna Coupler. Antenna coupler circuits provide impedance matching between the power amplifier output and the HF antenna. This impedance matching permits maximum power transfer to the antenna by minimizing the amount of Voltage Standing Wave Ratio (VSWR). The PAC is digitally tuned under the control of the R/T microprocessor. D-26

25 1) Initial tuning time is typically 1.0 second and tuning data for previously tuned transmit frequencies is stored in the R/T. The stored tuning data minimizes future tuning time when a frequency is used again with typical tune times of approximately 35 milliseconds. 2) Two PAC circuit breakers provide 28 VDC power over current protection for the R/T and the PAC itself. The PAC internal power supply operates from 28 VDC primary power. Figure 14. HF Grounded Loop Antenna. (4) HF Grounded Loop Antenna. The HF antenna is a grounded loop antenna. This antenna, also known as a towel bar, supports the Near Vertical Incident Skywave (NVIS) mode required for short range (0-300 km) NLOS communications. The HF antenna is located on the right side of the aircraft and runs the length of the tailboom. (a) (b) (c) The antenna provides a sufficiently efficient RF radiator at the lowest portion of the HF band (2.0 MHz), and does not degrade aircraft maintainability or transportability. Caution should be taken to avoid excessive impact and/or standing on the HF antenna towel bar. Although the HF antenna appears to be sturdy, it is relatively fragile and excessive forces applied to it may result in the antenna becoming inoperative without any visible indication of component failure. Due to the potentially high output power during HF transmissions, the Effective Radiated Power (ERP) is relatively high and a potential Radio Frequency (RF) radiation hazard as well as an electrical shock hazard exists for personnel around D-27

26 the HF antenna. The recommended minimum safe distance to be maintained from the HF antenna while the system is transmitting is five feet. Failure to remain clear of the HF antenna when transmitting may result in injury to personnel and/or damage to equipment. WARNING To avoid serious RF burns, do not touch an antenna or stand near an antenna when transmitting. Antennas radiate RF energy that can cause internal burns without causing sensation of heat. Ensure power is off before working around antennas. Figure 15. KY-100/TSEC Secure Voice Processor 1 of 2. (5) KY-100/TSEC Secure Voice Processor. The KY-100/TSEC advanced narrow band/wide band digital voice/data terminal or air terminal is a secure voice/data processor system designed for airborne application. (a) (b) (c) (d) This peripheral device provides for the encryption and decryption of analog and digital data while in the cipher mode. The KY-100 is located in the left aft avionics bay. It is mounted in console rails oriented vertically on the top shelf near the front of the bay. The KY-100 provides secure, half-duplex voice, analog data, digital data, and remote keying capabilities for transmission/reception over the HF radio. The KY-100 has over-the-air rekeying (OTAR) capability. The KY-100 has six selectable presets for crypto net variables (CNVs) and a manual (MAN) preset. D-28

27 (e) (f) (g) A compartment for a COMSEC battery is provided behind the front panel. A small cover on the outside of the front panel makes the compartment watertight and provides access to the battery. Two small screws retain the cover. The KY-100 uses a standard COMSEC BA-5372/U (lithium sulfur dioxide) battery. With the KY-100 turned off, the estimated battery life for the BA-5372/U is 5490 hours (approximately 7.5 months). As with most any battery, the effective life is dependent upon the actual shelf life and the timely usage of the battery. When the primary power is removed from the KY-100, COMSEC parameters and operating configurations are stored in Non- Volatile Memory (NVM) using battery-backed static random access memory (RAM) as the memory medium. The internally mounted COMSEC battery maintains the memory. Figure 16. KY-100/TSEC Secure Voice Processor 2 of 2. (h) Modes. The KY-100 has six operational modes that are selectable from the front panel rotary switch labeled MODE. 1) PT (Plain Text) permits transmission and reception of non-secure analog voice or analog/digital data. Voice/data signals are routed through active circuitry in the KY-100 to the HF radio. The PT mode allows analog voice and data input to bypass the digitized voice/data, COMSEC and modem processing functions and appear D-29

28 as an analog output from the KY-100. Only plain text reception is possible while in PT mode. 2) CT (Cipher Text) permits transmission of secure voice or data, reception of secure or non-secure voice or data. Plain text voice/data can be received provided CT ONLY is not selected from the KY-100 menu. Plain text reception is possible while in CT mode anytime a cipher text reception is not being processed. 3) RK (rekey) enables cooperative terminal rekeying, receive only. Cooperative rekeying of a KYX-15/TSEC net control device (NCD) requires that the NCD be connected to one of the FILL connectors located on either the front or rear panels of the KY ) OFL (off-line) disables communications and provides access to a system of menus used to select mode settings that determine configuration and self-test features. Additionally OFL provides access for filling the KY-100 with Crypto Net Variables (CNV). a) Menus are displayed on the front panel LCD. b) Mode options are selected using the three buttons (INIT ) below the LCD. 5) EB (emergency back-up) mode allows a zeroized KY- 100 to be used for voice privacy operation only. a) The KY-100 uses the emergency back-up key to encrypt/decrypt voice for transmission/reception. b) The emergency back-up key is stored in the KY- 100 apart from the other operational keys and is not subject to zeroizing. 6) Z ALL (zeroize) erases all secure data stored in the KY- 100 except the emergency back-up key. To select/deselect this option the MODE switch must be pulled out then turned in the appropriate direction. D-30

29 Figure 17. KY-100/TSEC Secure Voice Processor Bypass Assembly. (6) KY-100/TSEC Secure Voice Processor Bypass Assembly (a) (b) For normal HF radio operation, certain signals are always routed to the KY-100/TSEC secure voice processor location, regardless of whether one is installed or not. Because of this fact, the KY- 100/TSEC secure voice processor bypass assembly must be installed if a KY-100 is not installed or normal HF communications cannot occur. This bypass assembly consists of a jumper harness attached to a mounting bracket. To facilitate the operation of the HF radio without a KY-100/TSEC secure voice processor installed, the jumper harness is attached directly to the mounting via four Zeus-type fasteners. The bypass assembly supports both nonsecure voice and data communications for the HF radio. NOTE: If the bypass assembly is not installed, normal HF communications cannot occur. D-31

30 Figure 18. (7) Aft Utility Relay Panel (a) (b) (c) (d) (e) AFT Utility Relay Panel. With the KY-58/TSEC secure voice processor installed to support secure voice and data communications, the accommodation of a KY-58 component failure is as simple as selecting the Plain mode on the MPD. With the KY-58 in plain mode and the plain text/cipher text relays energized, the signals routed to the KY-58 go in and right back out as the KY-58 acts as merely a conduit for the signals. Although secure communication is inoperative, unsecured communication is still available. With the implementation of the KY-100/TSEC secure voice processor, the above mentioned operation does not hold true. If the KY-100 is installed and malfunctions, just selecting the plain mode does not provide the crewmember with unsecured communication capability. In the event of a catastrophic failure of the KY-100 component, all communications capability for the associated radio is rendered inoperative. Therefore, a means of bypassing the KY-100 is required. This bypass capability is provided via a series of relays located in the aft utility relay panel and, when implemented, allows the crewmember to bypass the HF radio s KY-100 with a selection on the MPD. The current bypass implementation only supports non-secure voice communications. D-32

31 Figure 19. (8) CY-8515 HF Battery Box (a) (b) HF Battery Box. The HF battery box is located in the right aft avionics bay, mounted on the bulkhead above the top shelf behind the Load Maintenance Panel (LMP). It contains five C cell batteries that are wired in series to provide approximately 7.5 VDC holding power to maintain the data fill and key fill data in memory when primary power is removed from the radio. D-33

32 Figure 20. (9) AN/ARC-220 Cooling Fan (a) (b) (c) (d) (e) Cooling Fan. The AN/ARC-220 (V) 2 HF radio system has a dedicated cooling fan located in the pass-thru bay. This fan is installed to provide cooling air for the PAC, also located in the pass-thru bay. The PAC generates a great deal of heat during operation; especially during transmit operation with high power selected. The cooling air is intended to dissipate the heat by convection and thus, prolong the operating life of the PAC. The cooling fan operates on 115 VAC power. To facilitate sufficient airflow through the bay and across the PAC, the right hand pass-thru bay door has been modified with a screened vent hole to act as an intake port. The fan is actually mounted on the left side of the bay with another screened vent hole provided in the aircraft fuselage to perform as an exhaust port. A squirrel cage screen surrounds the backside (intake) of the fan to preclude the entry of any debris that might cause damage to the fan. In addition, the cage prevents the possibility of bodily injury. D-34

33 CHECK ON LEARNING 1. What additional capability does the HF radio add to the aircraft? ANSWER: 2. What type of messages have a better chance of being received in a noisy electronic environment? ANSWER: 3. What is the WARNING related to the HF ground loop antenna? ANSWER: 4. The Power Amplifier Coupler (PAC) provide what output power levels to the radio? ANSWER: 5. What must be attached for HF operations to occur if the KY-100/TSEC is not installed? ANSWER: D-35

34 D. ENABLING LEARNING OBJECTIVE 4 ACTION: Describe HF Radio Page Operations CONDITIONS: Given a written test without the use of student notes or references. STANDARD: In Accordance With TM Learning Step / Activity 1 Describe High Frequency Radio Page Operations Figure 21. HF Page Status Windows a. The HF system has a discrete signal to indicate its presence and connection in the aircraft. If the radio system is not installed and connected properly, the HF NOT INSTALLED status window is displayed on the HF page and all of the HF radio selections are removed from the display. On power-up, the HF radio system executes an initialization sequence. (1) The HF INITIALIZING status window is presented and all HF radio selections are removed from the display. During initialization a PBIT is performed on all capable communication related systems. D-36

35 Figure 22. HF Page Initialization Complete. (2) Upon completion of the initialization sequence, the HF page is displayed with all of the available selections presented. The HF radio and KY- 100/TSEC initialize to the following state with the aircraft on the ground: (a) (b) Radio State Standby Radio Mode Manual (c) HF Modem? (d) (e) (f) (g) (h) (i) (j) (k) (l) Manual Frequencies State selected at shutdown Preset Channel State selected at shutdown ALE Net State selected at shutdown ECCM Net State selected at shutdown Call Address Default address for selected ALE net Link Protection State selected at shutdown Power Level State selected at shutdown Squelch Level State selected at shutdown Ground Transmit Override Disabled (3) The HF radio and KY-100 initialize to the state selected at shutdown with the aircraft in the air. D-37

36 b. DTU COM Load Figure 23. DTU COM Load. (1) Once the HF radio has initialized, it must be loaded with data from the DTU or an Air Navigation Crypto Device (ANCD). Operation of the HF radio is impeded if the radio has not been loaded with data from either device. (2) The HF radio can be operated in the manual state with manually tuned frequencies; however, most radio operations cannot be performed. NOTE: No HF data is loaded to the radio as part of a MASTER LOAD (button L1) on the DMS DTU DATA CURRENT MISSION page. (3) To load HF Radio data, perform the following functions on the MPD: (a) (b) (c) (d) (e) Select DMS Select DTU Select CURRENT MISSION Select COMMUNICATIONS Select / Load HF D-38

37 Figure 24. HF Radio Data Load. (4) On the DTU page in the COM DATA grouped options, selection of the HF button (R6) causes the HF radio data to begin uploading to the HF radio and the COMMUNICATIONS: HF RADIO status window to display. Figure 25. HF Status Window. (5) The Load Status window will display in LOAD IN PROGRESS and the HF button remains displayed in the OIP state for the duration of the upload. D-39

38 NOTE: There is only one day of upload data available for the HF radio. NOTE: On any HF page, the HF DATA FILL IN PROGRESS status window is displayed in white at the top center of the HF page and all HF radio selections are barriered until the HF data fill is complete. Figure 26. DTU Page HF Load Status Messages. (6) If the upload sequence runs to completion, a LOAD COMPLETED message is displayed on the load status line and any upload failures are presented in the DTU upload error list area just below the load status line. (7) Any errors are displayed in white and are listed in the order in which they occurred as the selected upload sequence proceeds. Deselecting the boxed HF button returns the crewmember back to the communications data selections. D-40

39 c. COM Page Figure 27. COM Page. (1) The COM page is used to manage the communication system for both voice and digital nets to include the HF system. It is accessible using the COM Fixed Action Button (FAB) or selecting the COM button (R6) from the Menu page. (2) The COM UTIL page (T6) provides specific controls for manual set-up and operation of the ARC-220 HF radio. The UTIL HF (L1) radio page provides specific controls for the set-up and operation of the ARC-220 HF radio. D-41

40 d. HF Page Figure 28. HF Page Clock Options. (1) HF Clock option buttons (R3 thru R6) allow the crewmember to control and display the HF radio time as maintained by the HF radio internal clock. The HF radio must be timed to function properly. (a) (b) Generally, this timing is accomplished using the GPS time and date as furnished by the primary EGI. It can also be performed by manual time and date input via the KU. Clock grouped option selections are used to perform the following: 1) GPS TIME button (R3): This option allows the radio to receive GPS time and date from the primary EGI provided the EGI has at least one satellite acquired. The data is then displayed under the corresponding CLOCK TIME and DATE data entry buttons. 2) HF TIME button (R4): This option extracts the current HF time and date from the HF radio and displays the data under the corresponding CLOCK TIME and DATE data entry buttons. This time and date are a instantaneous display of the HF radio internal clock state and are not continuously updated. For this reason, the time and date are considered stale after 60 seconds and are replaced by a? in the appropriate data fields. 3) TIME button (R5): Selection of this option provides the capability to manually enter the time into the HF radio via the KU. It also provides for display of the current time in the HF radio when either the GPS TIME or HF TIME buttons are selected. 4) DATE button (R6): Selection of this option provides the capability to manually enter the date into the HF radio D-42

41 via the KU. It also provides for display of the current date in the HF radio when either the GPS TIME or HF TIME buttons are selected. (c) Figure 29. HF State Options Page. NOTE: STBY is the default state upon aircraft power-up. Selection of the HF radio state is provided via the HF STATE button (L2) on the HF page. The HF radio system has three selectable states: Standby (STBY), SILENT, and Transmit/Receive (T/R). These options provide the following control measures: 1) STBY: In the STBY state, the HF radio is powered ON but it has no transmit or receive capability. The STBY state is primarily utilized to mode/configure the radio and, when required, is automatically selected momentarily to perform certain functions, then returns to the previously selected state. 2) SILENT: Selection of this state prevents the potential unauthorized transmission of the HF radio during refueling, ordinance loading, or personnel working near the HF antenna on the aircraft. In the SILENT state, the radio can transmit and receive, but only transmits upon crewmember selection. No automatic transmission capability is provided in this state. NOTE: A ground inhibit function (GND ORIDE) also prevents inadvertent transmissions from the HF radio, regardless of the HF radio operating state. D-43

42 WARNING In the ALE mode, the ARC-220 sounds (transmits short bursts), if programmed to perform this function via the data fill, and replies to ALE calls automatically without crewmember action. Anytime local flight directives forbid HF emissions, such as refueling, ordinance loading, or when personnel are working near aircraft, ensure the HF radio system is set to STBY or SILENT. 3) T/R: Normal HF communications, both manual and automated, can occur while operating in the T/R state provided the aircraft is in a flight condition (weight-offwheels) or the ground override (GND ORIDE) function is selected via the HF page on the MPD. (d) Figure 30. HF MODE Options Page. The HF radio operates in the following modes as selected (button L3) by the crewmembers for the mission requirements: 1) PRESET 2) MANUAL 3) ALE 4) ECCM 5) EMERGENCY D-44

43 (e) Figure 31. COM and MAN Pages. MANUAL mode allows for tuning of the HF radio from the COM MAN page on the MPD. 1) In this mode, the radio can transmit and receive on the same frequency, or it can use a different frequency for transmission. Entry of either a receive or transmit frequency on the MAN page automatically modes the HF radio to the manual mode of operation. 2) Tuning the HF Radio Manually a) Select the COM page b) Select the COM MANUAL page (L1) c) Enter a RECV frequency by selecting the SC/FH> button (R1) d) Enter receive frequency on the KU e) Enter a XMIT frequency by selecting the XMIT> button (R2) f) Enter transmit frequency on the KU D-45

44 (f) Figure 32. HF Manual Mode Page. The HF page displays the following unique buttons when in the MANUAL mode: 1) L2 HF STATE button 2) L3 HF MODE 3) L5 HF MODEM 4) R3 CLOCK GPS TIME 5) R4 CLOCK HF TIME 6) R5 CLOCK TIME entry 7) R6 CLOCK DATE entry 8) B3 GND ORIDE 9) B5 SET page 10) B6 ZERO page D-46

45 (g) Figure 33. HF and HF PRESET Pages. PRESET: The preset mode provides up to 20 preprogrammed frequency channels in which to tune the HF radio. These presets are programmed at the AMPS and loaded into the HF radio via the DTU or an ANCD. 1) Like the manual mode, the preset channels can have the same transmit/receive frequencies or different frequencies. 2) Selection of this mode provides access to the PRESET page where the desired preset channel can be selected for tuning. D-47

46 (h) Figure 34. HF ALE Mode. Automatic Link Establishment (ALE) mode: In the ALE mode, the HF radio works like a telephone. All the radios in a network are programmed with a set of frequencies. Up to 20 preprogrammed ALE nets with up to 20 frequencies per net can be loaded at the AMPS and uploaded to the HF radio via the DTU or an ANCD. The flight crew must select a Self Address from the COM INIT / ORIG ID page. NOTE: Failure to select a Self Address in the aircraft prevents the HF radio from performing ALE operations. 1) Selection of this mode requires access to the COM page to facilitate the selection of ALE net. The Next Channel for ALE operations can be changed on the HF page using the NEXT CHANNEL button. 2) The COM COMSETS & PRESETS page provides access to the HF ALE NETS where ALE nets can be selected for operation. 3) The ALE HOLD/CONNECTION (R1) button holds the current linked frequency. The frequency will remain on EUFD for 60 seconds after de-selection. 4) The crewmember selects a COM PRESET and initiates a call. The ALE system automatically links on the best available frequency for the current environment and notifies the crewmembers that a connection is established. Once a link is established, the ALE system operates the same as a conventional HF system. 5) INITIATE SOUND: Initiates sounding when in the silent state. D-48

47 6) ALL CALL: Transmits the call to all addresses listed in the current NET. 7) ABORT: Drops current connection. (i) Figure 35. HF ECCM MODE Page. ECCM mode: In the ECCM mode, the HF radio performs frequency hopping operation in an attempt to reduce/eliminate the effects of communication jamming equipment and direction finding attempts. Each radio in a net must have the same ECCM data fill and time of day to interchange voice or data in this mode. The following data is available: 1) Up to 12 preprogrammed ECCM nets can be programmed at the AMPS and uploaded to the HF radio via the DTU or an ANCD. Up to six ECCM keys can be loaded into the radio via an ANCD. 2) The COM COMSETS & PRESETS page provides access to the HF ECCM NETS where ECCM nets can be selected for operation. D-49

48 Figure 36. (j) HF EMERGENCY Mode Option. EMERGENCY: The emergency mode allows access to a preprogrammed radio configuration for use in an emergency. This configuration can be manual, preset, or ALE and is loaded at the AMPS and uploaded to the HF radio via the DTU or an ANCD. (k) Figure 37. HF and HF Modem Pages. The HF radio has a built-in modem to facilitate the sending/receiving of digital data from one HF radio to another D-50

49 including free text messages or a set of preprogrammed messages entered at the AMPS and uploaded to the HF radio via the DTU or an ANCD. 1) While in MANUAL mode, the HF radio modem configuration can be selected via the MODEM button (L5) on the HF page. Up to 12 preprogrammed modem configurations can be uploaded to the HF radio via the DTU or an ANCD. 2) In preset and ALE modes, the modem configuration is uploaded via the DTU or an ANCD to the radio. Each preset and ALE net can have a defined modem configuration that is automatically selected when a preset or ALE net is chosen for operation. When either of these modes is selected, the current modem configuration is not displayed anywhere in the crew station. NOTE: The modem configurations of the transmitting/receiving stations must match exactly or data transfer is not possible. (l) Figure 38. HF Self Address. To access the SELF ADDRESS page select the Com fixed action button, then select INIT button (T4), then select ORIG ID (L1). The Self Address button (R2) provides access to the SELF ADDRESS page and allows for the selection of one of up to 20 predefined Self Addresses configured at the AMPS and uploaded to the HF radio via the DTU or an ANCD. These Self Addresses are displayed on two pages with 10 addresses per page. 1) The Self Address can be considered as the ownship telephone number. It is utilized during ALE operations to D-51

50 identify the sender and receiver of an ALE call during the establishment of a communications link. The Self Address is also utilized during digital data transfer to identify the sender of a message, regardless of the selected HF radio mode. 2) The HF Self Address status window is displayed at the center of the page and indicates the currently selected own ship Self Address. If one has not been selected by the crewmembers, then a? is displayed on the bottom line of the data in the status window. NOTE: Failure to select a Self Address in the aircraft prevents the HF radio from performing ALE operations. (m) Figure 39. HF GND ORIDE. The ground override (GND ORIDE) button (B3) provides the crew with the capability, when selected (boxed), to override the HF ground safety inhibits. This action allows the crewmember to transmit on the HF radio while on the ground. Without GND ORIDE selected and operating on the ground, the HF radio is inhibited from transmitting, either manually or automatically. The GND ORIDE default state is OFF. NOTE: There is no visual indication, other than the HF page (boxed GND ORIDE) and UFD (boxed HF), to the crew that the HF radio GND ORIDE button on the HF page has been selected and that the HF radio is available for transmissions. WARNING GND ORIDE selection during FARP operations should not be used except in case of emergency. D-52

51 (n) (o) (p) (q) Figure 40. HF Set Page Options. The HF SET page is accessed via the SET button (B5) on the HF page. It provides the following additional controls for the setup and operation of the HF radio system: The LINK PROTECTION button (L2) provides the capability to enable/disable the link protection function associated with ALE operations. 1) This function utilizes the currently loaded link protection keys (LP1, LP2, and LP3) and the HF time/date in an attempt to prevent the use of an ALE net by unauthorized users. 2) The default setting is disabled. XMIT TIME button transmits your time to another radio. SYNC button synchronizes your time with another radio s time. D-53

52 (r) Figure 41. HF Set and POWER Pages. The POWER button (L5) permits the selection of the desired output power setting of the HF PAC during HF transmissions. The following options are available for selection: 1) LOW 10 watts 2) MEDIUM 50 watts 3) HIGH 100 watts average is the default power value upon power-up with 175 watts peak-to-peak. D-54

53 Figure 42. (s) HF Set and SQUELCH Pages. The SQUELCH button (L6) provides the capability to set the HF radio squelch level to one of five levels (1-5), which takes effect when the squelch is enabled on the COMM panel. 1) The higher the squelch value selected, the more squelch is applied and more noise reduction is achieved. There isn t a squelch value of zero available for selection. 2) Squelch can only be disabled via the HF squelch switch on the COMM panel. (t) Figure 43. HF SET Page and KY-100. HF SET Page CRYPTO Grouped Options 1) The HF CRYPTO grouped options MODE button (R1) provides for the remote selection of the desired mode of the KY-100. The crypto mode is configured at the AMPS and uploaded to the HF radio via the DTU or an ANCD. Upon power-up, the last crypto state used is restored. 2) These modes are selectable, provided the KY-100 is installed, but only take affect if the MODE switch on the KY-100 face panel is set to CT. D-55

54 Figure 44. HF SET and CRYPTO Option Pages 1 of 2. (u) The four available CRYPTO MODE selections are: 1) PLAIN: The PLAIN mode permits transmission and reception of unencrypted analog voice. The voice signals are routed through active circuitry in the KY-100 to the HF radio. Only plain text reception is possible while in PLAIN mode. 2) CIPHER: Selecting CIPHER mode permits the transmission of encrypted voice or data messages. In addition, reception of encrypted and unencrypted voice or data is accomplished. 3) RECEIVE: The RECEIVE mode enables the Over-The- Air-Rekey (OTAR) capability of the KY-100 and allows for the loading of CNVs via secure RF link. 4) OFFLINE: The OFFLINE mode disables communications and provides access to a system of menus used to select mode settings that determine configuration and self-test features. This mode also provides access for filling the CNV's. NOTE: A significant amount of delay will be experienced while attempting to manipulate the KY- 100 from the crew station in the OFFLINE mode. It is highly recommended that any offline manipulation of the KY-100 be performed through the face panel of the KY-100 itself. D-56

55 Figure 45. (v) HF SET and CNV Option Pages. HF CRYPTO CNV button (R2) provides for the remote selection of the CNV for use during CIPHER and RECEIVE mode operations. 1) In the CIPHER mode, the selected CNV is the one being used for actual encryption/decryption of voice or data. 2) In the RECEIVE mode, the selected CNV is the CNV memory location in the KY-100 where an incoming CNV is to be stored following a successful OTAR. D-57

56 (w) (x) (y) (z) Figure 46. HF SET Page. The UP ARROW (R3) and DOWN ARROW (R4) buttons provide the capability to scroll up or down thru the KY-100 menu system. The BACK button (R5) provides the capability to back out of KY- 100 menus. The INITIATE button (R6) provides the capability to initiate selections from the KY-100 menus. The BYPASS button (B6) provides the capability to bypass the KY-100 in the case of a catastrophic failure of the KY-100. This allows the HF radio to be used in the plain mode. All other CRYPTO grouped options are removed from the display with the BYPASS selection. Figure 47. CRYPTO Status Window. (2) The CRYPTO status window is displayed in the center of the page format and presents the current settings and overall status of the KY-100 for the HF radio. It displays the following information concerning the operation of the KY-100: (a) (b) (c) (d) (e) (f) (g) Mode of operation Overall status Transmit (XMIT) or Receive (RECV) mode Voice or Data mode Baud rate Wide Band (WB) or Narrow Band (NB) mode Menu lock status D-58

57 (3) The CRYPTO group options and CRYPTO status window are removed from the display if a KY-100 is not installed in the aircraft, Management by Exception rule. Figure 48. HF Zero Page. (4) The HF ZERO page provides controls to zeroize the data fill, key fill, or both fills from the HF radio. The selection of any of these zeroize buttons provides a corresponding confirmation grouped option with YES and NO selections displayed. Figure 49. COM Page with COMSETS or PRESETS Selected. D-59

58 e. The HF radio can be tuned to a tactical preset in the following manner: (1) Select the COM page (2) Select COMSETS OR PRESETS (L1). (3) Select COMSET OR PRESET center of page. (4) Select the desired COMSET and TUNE the entire COMSET is tuned. (5) Select the desired PRESET then select desired net on right side. NOTE: The HF STATE must be set to either T/R or SILENT on the HF page prior to tuning the HF radio to a tactical preset configuration or attempting to transmit. NOTE: SELF ADDRESS must be entered prior to use of ALE mode. Figure 50. COM PRESET EDIT Page HF Selections. f. The COM PRESET EDIT page HF Selections (1) With one of the presets selected and the EDIT function on (boxed), the preset status window is displayed in the center of the page with all corresponding frequencies and channels displayed by radio. The following HF radio information will be displayed within the preset status window if the information was loaded within the preset: (a) (b) (c) (d) (e) (f) EDIT FREQS Button (L1) selected. Preset descriptor and callsign (L2&3) edit via KU. MODE Button (R1) selects radio mode. ALE / ECCM NET (R2) select ALE or ECCM. CALL Address (R3) selects call address page. CRYPTO (R4&5) selects Mode and CNV. (2) The COM PRESET EDIT page provides the crewmembers the capability of changing (editing) any data concerning the selected preset. When the D-60

59 PRESET EDIT page is displayed the controls for editing the HF radio data are displayed along the left and right. (3) Items available for editing for each EDIT option are displayed in full intensity within the PRESET status window. Figure 51. HF PRESET EDIT Options Page. (4) The HF options available for editing include: (a) (b) (c) The MODE button (R1) changes HF Mode to ALE or ECCM. The ALE NET button (R2) changes the HF ALE net number of the preset selected to a selection between 1 and 20. The ECCM NET button (R2) changes the ECCM net number of the preset selected to a selection between 1 and 12. (d) CALL ADDRSS button (R3) changes call address, 14 pages 10 per page. (e) CRYPTO options: 1) MODE button (R5) changes the mode of the HF between plain and cipher for the selected preset. 2) CVN button (R6) changes which CVN the HF radio will use if tuned on the selected preset. D-61

60 Figure 52. (f) HF RECV Grouped Options Page. Mode SC grouped option (buttons R1) give crewmembers the following capabilities: 1) The FREQ> button (R2) changes the HF Manual Receive frequency of the preset to a frequency in the HF range, entered via the KU. 2) The HF XMIT FREQ> button (R3) changes the HF Manual Transmit frequency of the preset to a frequency in the HF range, entered via the KU. Figure 53. g. HF Radio System Advisories HF Radio UFD Advisories. (1) HF radio system related advisories are displayed on the UFD but they are not in the normal advisory area. (2) HF radio advisories are displayed on the second line of HF radio data between the current and last transmit frequencies/modulation types. D-62

61 (a) (b) HF related advisories available for display are dependent upon the system mode of operation. The various modes and related advisories are as follows: 1) Common Advisories: a) ZEROIZED HF radio data is being zeroized b) STANDBY HF radio is in standby mode 2) Manual and Preset Mode Advisories: a) RECVING DATA HF radio is currently receiving digital data b) PP RECEIVED HF radio has received a present position report c) SENDING DATA HF radio is currently sending digital data d) CHECK MSG HF radio has received a new digital message and it is stored in the radio for future viewing. e) GO DATA ONLY HF radio transmission quality is poor. This is a suggestion to switch to data only in an attempt to get a message across. 3) ECCM Mode Advisories: a) ANT TUNING HF radio is antenna tuning b) ANT UNTUNED HF radio ECCM net is not pre-tuned c) XMIT READY HF radio has transmitted ECCM preamble and is ready to transmit voice or data 4) ALE Mode Advisories: a) RECVING CALL An ALE incoming call is being received. b) CALL RESPND? HF radio is in silent mode and an incoming ALE call is detected. Either crewmember must press the HF PTT or the ALE call will fail for the initiator. c) RECVING DATA HF radio is currently receiving digital data. d) SOUNDING HF radio is currently sounding. e) SENDING TIME HF radio is attempting to change another radio s time over the air. f) SYNCING HF radio is attempting to time sync with another radio. g) CALLING An ALE call is being transmitted. h) PP RECEIVED HF radio has received a present position report. D-63

62 i) SENDING DATA HF radio is currently sending digital data. j) CHECK MSG HF radio has received a new digital message and it is stored in the radio for future viewing. k) CALL FAILED All attempts for an initialized ALE link have failed. l) LINKED HF radio is currently ALE linked with another radio. Communications can now take place. m) UNSYNC HF radio is currently not synced. n) GO DATA ONLY HF radio transmission quality is poor. This is a suggestion to switch to data only in an attempt to get a message across. 5) Data Fill Advisories: a) FILL WAITING HF radio is currently being loaded with data fill. b) FILL RECVING HF radio is currently being loaded with data fill. This advisory is not displayed when the HF data fill upload is accomplished via the DTU. c) FILL PROCESS HF radio is currently being loaded with data fill. This advisory is not displayed when the HF data fill upload is accomplished via the DTU. d) FILL CHECK HF radio is currently being loaded with data fill. This advisory is not displayed when the HF data fill upload is accomplished via the DTU. D-64

63 Figure 54. COM MAIL Page With HF Source Selected. h. HF Radio System Mail Send (MAIL SEND) and Receive (HF INBOX) Pages (1) On the COM MAIL page with MAIL TEXT (L1) and MAIL TYPE (L2) MPS plus NET (L3) HF; up to 25 preprogrammed HF messages can be selected for review and/or sending via the HF radio. Five pages are available with up to 5 messages per page. With a HF preprogrammed message selected, the SEND button (R6) is displayed and allows for the transmission of the selected message via the HF radio. (2) When the SEND button is selected the message is sent and the SEND button is replaced with RESEND. (3) When the Message is selected the bottom window allows the crewmember to review the entire message prior to sending it. D-65

64 Figure 55. MSG SEND With PP Selected. (4) With MAIL RPT (L1) AND MSG TYPE PP (L2) selected, the SEND (R6) button is provided to transmit the own ship PP to other HF radios. (a) This position message contains the following data: 1) The first three characters of the sender s Self Address 2) The current latitude and longitude of the aircraft 3) The current means sea level (MSL) altitude of the aircraft (5) When the SEND button is selected, it is displayed as OIP (inverse video) until the message is successfully sent, or the message send time-out period expires. D-66