CHAPTER 1

COMMUNICATIONS HARDWARE

LEARNING OBJECTIVES

Upon completing this chapter, you should be able to do the following:

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Determine the equipment required for each communications system.

Identify the hardware setup procedures for radio systems.

Identify the use of COMMSPOTS.

Identify procedures and requirements for communications equipment as itpertains to OTAR/OTAT functions.

Determine utilization, frequencies and watches needed for distresscommunication equipment.

Interpret how to monitor circuit quality equipment.

The high-paced operations required of modern fleetunits demand communication systems that are capableof providing high-speed, accurate, and securetransmission and reception of intelligence. To keeppace with the ever-increasing complexity of operations,today’s communication systems are necessarily highlysophisticated and versatile. For our ships andsubmarines to operate effectively, whetherindependently or as part of a battle group, they musthave communication systems and operators that arecapable of meeting this challenge.

In this chapter, we will discuss various aspects offleet communication systems. As a Radioman, you willbe responsible for knowing the differentcommunication systems used by the Navy and whatcommunication equipments make up a system.

COMMUNICATIONS SYSTEMS

Through equipment design and installation, manyequipments are compatible with each other and can beused to accomplish various functions. Using this designconcept, nearly all the communication needs of a shipcan be met with fewer pieces of communicationsequipment than were previously required.

Communications can be maintained at the highestpossible state of readiness when all levels of commandunderstand the capabilities and limitations of thesystems. Many communications failures areattributable to poor administration rather than toequipment failure or technical problems.

In this section, we will discuss predeploymentreadiness; low-, high-, very-high-, ultra-high-, andsuper-high-frequency communications systems; andequipment components that comprise these systems.

UNDERWAY PREPARATION

Ships deploying to overseas areas must be in a stateof maximum operational and communicationsreadiness. Type commanders determine the level ofreadiness of deploying ships and ensure they areadequately prepared.

A check-off list is an excellent method to ensurethat step-by-step preparations are completed prior to adeployment. This list should cover all aspects ofcommunications readiness and should begin well inadvance of the underway period. Some of the points tobe checked include scheduling of communicationsassistance team (CAT) visits, maintenance and

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operational checks of equipment and antennas, andconsumable supply levels.

The Basic Operational Communications Doctrine(U), NWP 4 (NWP 6-01), provides suggestedminimum check-off sheets , inc luding apredeployment check-off sheet and a preunderwaycheck-off sheet. The first sheet provides a timetable ofrequired checks and objectives. The second sheet istailored to individual ships and unique requirements.

LOW-FREQUENCY SYSTEMS

The low-frequency (LF) band (30-300 kHz) is usedfor long-range direction finding, medium- and long-range communications, aeronautical radio navigation,and submarine communications.

A low-frequency transmitter, such as the AN/FRT-72, is used to transmit a high-powered signal overlongdistances. Low-frequency transmitters are normallyused only at shore stations or for special applications.

The low-frequency receive system is designed toreceive low-frequency broadcast signals and toreproduce the transmitted intelligence. A typical low-

frequency receive system is shown in figure 1-1. Referto the equipments in the figure as you study the nextsection.

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Antennas— The low-frequency signal isreceived by the antennas, which are connectedto the receiver antenna patch panels andmulticouplers (AN/SRA-34, AN/SRA-57, orAN/SRA-58). Multicouplers and patch panelsallow the operator to select different antennasand connect them to different receivers. Thisway, an operator can select the correctcombination suited for a particular system.

LF Receiver— The output of the receiver(audio) is fed to the receiver transferswitchboard.

Switchboard— The switchboard can connectthe receiver output to numerous pieces ofequipment. In figure 1-1, the receiver output isconnected to the AN/UCC-1 TeleprinterTerminal (discussed later).

AN/UCC-1— The AN/UCC-1, as a convertercomparator, converts the received audio signal

Figure 1-1.—Low-frequency receive system.

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(AF) to direct current (dc) for use by theteleprinter equipment.

Black dc Patch Panel— The dc output of theAN/UCC-1 is fed to the SB-1203/UG DC PatchPanel. The dc patch panel permits the signal tobe patched to any cryptoequipment (discussedlater) desired.

Cryptoequipment— The cryptoequipmentdecrypts the signal and connects its output to thered SB-1210/UGQ DC Patch Panel.

Red dc Patch Panel— The SB-1210/UGQ canbe patched to a selected printer that prints thesignal in plain readable text.

HIGH-FREQUENCY SYSTEMS

The high-frequency (HF) band (3-30 MHz) isprimarily used by mobile and maritime units. Themilitary uses this band for long-range voice andteleprinter communications. This band is also used as abackup system for the satellite communications system.We will discuss satellite communications later in thischapter.

Figure 1-2 shows a typical high-frequency transmitsystem. In transmitting teleprinter information, theequipments shown in figure 1-2 perform the samefunctions as the equipments shown in figure 1-1, exceptthe equipments in the high-frequency system do thefunctions in reverse order.

In the HF transmit system, the AN/UCC-1Telegraph Terminal converts dc signals into audio tonesignals. The output of the AN/UCC-1 is connected tothe transmitter transfer switchboard. The C-1004Transmit Keying and Receive Control/Teleprinter isused to key the transmitter during teleprinteroperations.

Voice communications from some remote locationsare also connected to the transmitter transferswitchboard. Voice communications are initiated at ahandset (remote phone unit) and connected to the C-1138 Radio Set Control. The output of the radio setcontrol is connected to the transmitter transferswitchboard. The transmitter transfer switchboardpermits the operator to select the proper transmitter forthe frequency to be transmitted.

Figure 1-2.—High-frequency transmit system.

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Figure 1-3.—High-frequency receive system.

Figure l-3 shows atypical high-frequency receivesystem. Refer to the figure as we follow the signal paththrough the system.

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A transmitted high-frequency signal is receivedby the antenna, which converts electromagneticenergy to electrical energy.

The signal travels through a transmission line toan antenna patch panel, where it can bedistributed to any of a number of receivers.

The receiver converts the RF signal into ateleprinter or voice signal, depending upon whatis desired.

The output of the receiver is then sent to thereceiver transfer switchboard.

If a teleprinter signal was selected, theteleprinter signal from the switchboard goes tothe AN/UCC-1 and then follows the same pathas we described in the low-frequency receivesection. Identical pieces of equipment are used,and they perform the same functions.

If a voice signal was selected, the voice signalfrom the receiver transfer switchboard is sent tothe radio set control. The output is then sent to ahandset. The voice signal can also be sent fromthe switchboard to a remote speaker amplifier.There, it can be placed on a speaker so that the

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user can listen to the received signal withoutholding onto the handset.

VERY-HIGH-FREQUENCY SYSTEMS

The very-high-frequency (VHF) band (30-300MHz) is used for aeronautical radio navigation andcommunications, radar, amateur radio, and mobilecommunications (such as for boat crews and landingparties). Figure 1-4 shows a basic block diagram of a

Figure 1-4.—Very-high-frequency transmit and receivesystem.

VHF transmit and receive system using a transceiver.Although a transceiver is used in this system, thetransmit and receive systems are described separately.Refer to figure 1-4 as we follow the signal path on thetransmit side of the system.

On the transmit side of the system, the operator, at aremote location:

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Talks into the handset.

The handset is connected to the C-1138 RadioSet Control.

The output of the radio set control is sent to thetransmitter transfer switchboard.

The output of the switchboard is sent to thetransmit side of the transceiver.

The transceiver converts the input signal to anRF signal for radiation by the antenna.

Continue to refer to figure 1-4 as we follow the path ofthe incoming signal.

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The incoming signal in figure 1-4 is received bythe antenna.

This signal is sent to the receive side of thetransceiver.

The output of the transceiver is sent to thereceiver transfer switchboard.

From the receiver transfer switchboard, theoutput is sent to either the C-1138 Radio SetControl or to a speaker amplifier, or both,depending on the preference of the user.

The output of the radio set control is sent to ahandset.

6. A speaker receives the output of the speakeramplifier.

ULTRA-HIGH-FREQUENCY SYSTEMS

The ultra-high-frequency (UHF) band (300-MHzto 3-GHz) is used for line-of-sight (short-range)communications. The term “line of sight,” as used incommunications, means that both transmitting andreceiving antennas must be within sight of each otherand unaffected by the curvature of the Earth for propercommunications operation.

The UHF band is also used for satellitecommunications. Although satellite communicationsare line of sight, the distance the signal travels is muchgreater than that of UHF surface communications,because the antennas remain in sight of each other.

As in the VHF section, the transmit and receivesystems will be described separately. Figure 1-5 showsa basic block diagram of a UHF transmit system, whichuses a transceiver.

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On the transmit side of the nonsecure voicesystem, the operator at a remote location talksinto the handset. The handset is connected to theC-1138 Radio Set Control.

The C-1138 is connected to the transmittertransfer switchboard, where it is patched to thetransmitter.

The operator at a remote location talks into thesecure voice remote phone unit (RPU).

The RPU is connected to the secure voicematrix. This is the tie point for connecting morethan one RPU. The output of the matrix is

Figure 1-5.—Ultra-high-frequency transmit system.

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connected to the secure voice equipment, whichencrypts the information received.

The output of the secure voice equipment isconnected to the transmitter transferswitchboard.

The transmitter transfer switchboard is used toconnect numerous RPUs to any number oftransmitters.

The output of the patch panel is connected to thetransmitter side of the transceiver, which, inturn, is connected to an antenna coupler.

Figure 1-6 shows a basic diagram of a UHF receivesystem. We will next follow the UHF signal paththrough the receive side of the system.

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The received signal is picked up by the antennaand connected to the receiver side of thetransceiver through the antenna coupler.

The output of the receiver is connected to thereceiver transfer switchboard. From here, it canbe connected to either the nonsecure or thesecure voice systems, depending upon the modeof transmission.

When a nonsecure signal is received, the outputof the receiver transfer switchboard can beconnected to the radio set control or a speakeramplifier, or both, depending on the preferenceof the user.

The output of the radio set control is connectedto a handset, whereas the output of the speakeramplifier is connected to a speaker.

If a secure voice transmission is received, theoutput of the receiver transfer switchboard is

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connected to the secure voice equipment, whereit is decrypted.

The secure voice equipment output is connectedto the secure voice matrix. The secure voicematrix performs the same function as the matrixon the transmit system.

The secure voice matrix output is connected tothe secure remote phone unit. Here, the signal isconverted back to its original form.

SUPER-HIGH-FREQUENCY SYSTEMS

The super-high-frequency (SHF) band (3-30 GHz)is strictly for line-of-sight communications. It isconfigured much the same as the UHF system. SHF ismainly used for satellite communications.

SHF satellite communications is a high-volumesystem that offers reliable tactical and strategiccommunications services to U.S. Navy elements ashoreand afloat. The system is composed of the terminalsegment, consisting of U.S. Navy-operated Earthterminals and mobile terminals. It also includes aportion of the Defense Satellite CommunicationsSystem (DSCS) satellite segment. Navy Super HighFrequency Satellite Communications, NTP 2, Section1 (C), provides comprehensive coverage of the NavySHF satellite system.

PATCH PANELS

Teleprinter patch panels are used for theinterconnection and transfer of teleprinter signalsaboard ship. In the previous block diagrams two patchpanels, one labeled red, the other black, were shown.These are the teleprinter patch panels SB-1210/UG and

Figure 1-6.—Ultra-high-frequency receive system.

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SB-1203/UGQ (figure 1-7). The SB-1210/UG isintended for use with cryptographic devices; the SB-1203/UGQ is a general-purpose panel.

The patch panels are red or black to identify secureand nonsecure information. Red indicates that secure(classified) information is being passed through thepanel. Black indicates that nonsecure (unclassified)information is being passed through the panel.

Both panels are also labeled with signs. The redpanel sign has 1-inch-high white block letters that read“RED PATCH PANEL.” The black panel normally hastwo black signs containing l-inch-high white blockletters. One sign reads “BLACK PATCH PANEL” andthe other, “UNCLAS ONLY.”

Each panel contains six channels. Each channel hasits own series circuit of looping jacks, set jacks, and arheostat for adjusting line current. The number oflooping and set jacks in each channel varies with thepanel model. Each panel includes a meter and rotaryselector switch for measuring the line current in anychannel.

Six miscellaneous jacks are contained in eachpanel. Any teleprinter equipment not regularlyassigned to a channel maybe connected to one of thesejacks. In some instances, commonly used combinationsof equipment are permanently wired together within thepanel (called normal-through).

Figure 1-7.—Teleprinter patch panels.

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CRYPTOGRAPHIC EQUIPMENT

Some of the systems in the previous figurescontained cryptographic equipment. Cryptographicequipment is only one of a number of the elements thatmake up a secure communications system. Thoughseveral different types of on-line cryptoequipments arein use throughout the naval communications system,they are all designed to perform the same basic function:to encipher and decipher teleprinter or digital datasignals.

Simply stated, the transmitter accepts a “plain text”teleprinter or data signal containing classified materialfrom the classified patch panel (red). It then adds a“key,” and relays the sum as “cipher text,” or anenciphered signal. A key is a sequence of randombinary bits used to initially set and periodically changepermutations in cryptoequipment for decryptingelectronic signals.

Following this encryption, the signal is fed to theunclassified patch panel (black). Here, it is patcheddirectly to the frequency-shift keyer or the multiplexequipment of the transmitter and converted into anaudio signal. The audio signal, now in a form suitablefor transmission, is routed to the transmitter via thetransmitter transfer switchboard.

On the receive side, the signal flow is quite similarto the send side in reverse order. The receiver acceptsthe enciphered signal from the black patch panel andgenerates a key to match the one generated by thetransmitter. The receiver then subtracts the key from thecipher text input (which restores the plaintextteleprinter or data signal). Finally, it passes the signalon to the red patch panel for dissemination to theterminal equipment for printout.

For further information and operator instructionson a specific type of cryptoequipment, refer to theapplicable KAO publication.

AN/UCC-1 TELEGRAPH MULTIPLEXTERMINAL

Because of the traffic volume handled, many shipsand shore stations require multiple teleprinter circuitson one sideband circuit. The method for increasingcircuits on a sideband is called multiplexing. The Navyuses two multiplexing techniques in communications:time division and frequency division. The AN/UCC-1Telegraph Multiplex Terminal uses the frequency-division technique.

The AN/UCC-1 Telegraph Multiplex Terminal(figure 1-8) is a frequency-division multiplexedterminal equipment for use with single-sideband (SSB)or double-sideband (DSB) radio circuits, audio-frequency wire lines, or microwave circuits. TheAN/UCC-1 is normally used afloat on a multichannelship-shore full-period termination (discussed later).

The following is an overview of how the AN/UCC-1 works:

At the transmitting station, the signals from theindividual circuits, known as channels, aremultiplexed into one composite signal fortransmission. The transmission with themultiplexed channels is known as a tonepackage.

At the receiving station, the composite signal(tone package) is demultiplexed (separated) intoindividual signals and distributed to separateteleprinters, as required.

The terminal can operate in a nondiversity, audio-frequency diversity, space diversity, or radio-frequencydiversity mode. Because of this versatility, the terminalis installed in various configurations throughout theNavy.

Each electrical equipment cabinet houses onecontrol attenuator (right side) and up to a maximum ofeight frequency-shift keyers or eight frequency-shiftconverters.

Since the control attenuator, keyers, and convertersare solid-state, integrated-circuit, plug-in modules, thenumber of channels can be varied by increasing ordecreasing the total number of modules. Dependingupon the number of modules and the configurationused, the terminal can provide up to 16 narrowbandchannels.

For example, if the terminal has keyers in the topcabinet and converters in the bottom cabinet, the systemcould transmit different information on eight channels.Each keyer would represent a channel on the transmitside and each converter, a channel on the receive side.

Each frequency-shift keyer accepts a dc telegraphsignal input from an external loop and generates theappropriate audio-frequency mark and spacefrequency-shift output. The individual keyers eachcontain two oscillators operating on opposite sides of acenter frequency. For example, in figure 1-9, the centerfrequency of keyer number one is 425 Hz, the markfrequency is 382.5 Hz, and the space frequency is 467.5

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Figure 1-9.—Keying frequencies of the AN/UCC-1.

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Hz. These audio-frequency mark and space outputs arereferred to as “tones”; thus keyer one has a one-channel,two-tone output.

A dc telegraph signal on channel 1 determineswhich frequency is gated from the keyer to the groupattenuator. Each channel works in the same way. Itaccepts a dc signal of marks and spaces from selectedequipments patched to that channel. It then provides anaudio output of either a mark or space frequency-shiftedtone, according to the input.

The individual tones are combined at the controlattenuator into a composite tone package. The controlattenuator ensures that the composite tones remain at aconstant amplitude for modulating the transmitter.

At the receiving end of the communications link,the AN/UCC-1 reverses the process performed at thetransmitting end. The AN/UCC-1 applies theinformation on each of the channels to the selectedequipments connected to the converter of that charnel.

In a frequency-division circuit configuration, eachchannel has an input from a different teleprinter. If achannel fades at a particular frequency, the informationon the channel could be lost or distorted. In such cases,the information may need to be retransmitted. To helpprevent this, diversity switches that will permit the useof more than one channel for the same intelligence areavailable.

In switch position 1, only the normal channel isused. In position 2, a single teleprinter signal providesinput for two adjoining keyers. In position 4, fourkeyers are connected to the same input loop. Theswitches on all keyers must be in the same position toprovide the same intelligence to the selectedcombination of channels.

When identical intelligence untransmitted on two orfour channels, it is less likely to be lost or distorted. Atthe receiving end, two or four corresponding convertersmay be used; the converter having the stronger signal

input automatically provides the signal to be used by thereceiving teleprinter.

In the fleet broadcast multiplexing system, whichconsists of 16 channels, 2 channels normally carry thesame intelligence. This process is called twinning.

Another method of multiplexing mentioned earlieris time-division multiplexing (TDM). In this method, adigital input is fed to a TDM unit. Here, it ismultiplexed into a composite intelligence stream fortransmission. The output is sent to an end user, where itis broken into its original individual inputs.

However, instead of splitting the frequencies as infrequency-division multiplexing (FDM), TDM sharestime. Each input uses the full bandwidth of the assignedfrequency but is assigned unique time portions of thesystem. Figure 1-10 illustrates the front panel of a full-duplex time-diversity modem.

SHIP-SHORE CIRCUITS

As we mentioned earlier, the fleet broadcast is theprimary means for delivering messages to afloatcommands. This section discusses a few of the othertypes of circuits by which a ship can transmit itsmessage traffic ashore or to other ships for delivery orrelay.

SHIP-SHORE CIRCUIT MODES OFOPERATION

There are three methods of operatingcommunications circuits: duplex, simplex, andsemiduplex. The mode of operation at any given timedepends upon equipment and frequency availability.

Duplex

Duplex describes a communications circuitdesigned to transmit and receive simultaneously. Insuch operations, each station transmits on a differentfrequency and both stations transmit concurrently. Both

Figure 1-10.—Full-duplex time-diversity modem.

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stations are required to keep transmitters on the air at alltimes and to send a phasing signal at the request of thedistant end. Figure 1-11 shows a diagram of a UHF/HFfull-duplex FSK (frequency-shift keying) single-channel teleprinter relay circuit.

There are two types of duplex operation: fullduplex and half duplex. Full duplex (FDX) refers to acommunications system or equipment capable oftransmitting simultaneously in two directions. Halfduplex (HDX) pertains to a transmission over a circuitcapable of transmitting in either direction, but only onedirection at a time.

Small ships traveling in company normally useduplex in a task group common net in which theyterminate with a larger ship that is serving as net control.The net control ship provides the ship-shore relayservices. Ships traveling independently can use this

system for anon-call ship-shore termination to transmittheir outgoing messages.

Simplex

Simplex is a method of operation that provides asingle channel or frequency on which information canbe exchanged (figure 1-12). Simplex communicationsoperation is normally reserved for UHF and those shipsthat do not have sufficient equipment for duplexoperation. In some cases, a simplex circuit can beestablished when equipment casualties occur.

Where no HF simplex frequency is indicated orguarded, ships requiring a simplex ship-shore circuitmust call on a duplex ship send frequency. The shipmust state “SIMPLEX” in the call-up, indicating thatthe ship cannot transmit and receive simultaneously.

Figure 1-11.—UHF/HF full-duplex FSK single-channelteleprinter relay circuit.

Figure 1-12.—UHF/HF netted simplex FSK teleprinter relaycircuit.

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When a ship requests simplex operation on duplexcircuits, the shore station may be required to shifttransmitters prior to acknowledging call-up. If no replyis received within 45 seconds, the ship should repeat thecall-up procedures. If a third attempt is required, theship should check equipment to ensure properoperation.

Semiduplex

Semiduplex communications circuits, usedprimarily on task force/task group/ORESTES, are acombination of the simplex and duplex modes. Allstations except the net control station (NECOS)transmit and receive on the same frequency. TheNECOS transmits and is received on a secondfrequency. The NECOS may transmit continuously,whereas all other stations must transmit in accordancewith simplex procedures.

UHF/HF RELAY

The UHF/HF relay method permits long-range,uninterrupted communications during periods ofhazardous electromagnetic radiation (HERO). Figure1-13 shows a block diagram of a UHF/HF voice relaycircuit.

Modern radio and radar transmitting equipmentsproduce high-intensity RF fields. It is possible for RFenergy to enter an ordnance item through a hole or crackin its skin or to be conducted into it by firing leads,wires, and the like. Here is an example of HERO. Anaircraft carrier is arming aircraft on board. Duringarming operations, all HF transmitters must be securedto prevent possible detonation of the ordnance. Tomaintain its ship-shore communications, the carriertransmits to a relay ship via a UHF circuit. The relayingship then retransmits the signal on a HF circuit to aterminated NAVCOMTELSTA. On-l ine

Figure 1-13.—UHF/HF voice relay circuit.

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radioteleprinters can be relayed, as well as voice, usingthis circuit.

SECURE VOICE WORLDWIDE VOICENETWORK

The secure voice network is designed to providered-time voice communications between forces afloatand operational commanders ashore, using either HF orsatellite connectivity. This system is commonlyreferred to as GPS Worldwide HICOMM.

System Control

This system consists of three separate networks.Each network has an area control station controlled by aFLTCINC; either CINCLANTFLT, CINCPACFLT, orCINCUSNAVEUR. Each area has subarea controlstations determined by each FLTCINC to ensureworldwide coverage.

Satellite System Control

The secure voice system, using satellitetransmissions, has limited shore access points at thefour COMMAREA master s ta t ions andNAVCOMTELSTA Stockton, California. These sitesserve as the interface channel to both the wideband andnarrowband voice systems in order to extend calls tooperational commanders ashore.

Net Membership

If a ship, aircraft, or shore station needs to enter thesecure voice network, it must be prepared to do so withminimum time delay. Units desiring to enter the net on atemporary basis must specify the length of time andpurpose for entering the net. They must also obtainpermission from the appropriate control station. Thearea net control station (NECOS) is responsible forcompleting all calls originating from senior commandsto all commands, ships, or aircraft within the specificFLTCINC’s net. Certain rules must be observed whenon the secure voice net, as follows:

HF transmitter tuning is prohibited on securevoice. Transmitters must be calibrated andpretuned on a dummy load. Final tuning may beaccomplished during live transmissions.

All stations must maintain a continuous log onsecure voice. The actual time of significanttransmissions must be entered into the log.When available, recording devices must be usedin lieu of a paper log.

The net operates as a free net unless otherwisedirected by the area FLTCINC. NECOS retainsthe prerogative of exercising control over alltransmissions to ensure proper circuit discipline.

FULL-PERIOD TERMINATIONS

Full-period terminations are dedicated circuits thatprovide communications between shore stations andafloat commands. These terminations requireallocation of limited NCTAMS/NCTS assets.Therefore, the criteria for requesting, approving, andestablishing such circuits is necessarily strict.

Termination Requests

Afloat commands and individual units can requestfull-period termination during special operations,deployments, intensive training periods, or exerciseswhen primary ship-shore circuits will not suffice.Commands should request full-period terminationsonly when traffic volume exceeds speed and capabilityof ship-shore circuits and when operational sensitivityrequires circuit discreetness or effective command andcontrol necessitates dedicated circuits.

T h e h e a v y d e m a n d s p l a c e d u p o nNCTAMS/NCTSs for full-period terminations requiremaximum cooperation between shore stations andafloat commanders prior to and during an operation.Ships having a need for a full-period termination, eitherfor training or operational requirements, must submit atermination request to the COMMAREA master stationat least 48 hours prior to activation time.

Emergency commitments or a command directivemay necessitate a lead time of less than 48 hours.Whenever possible, however, the 2-day limit must behonored to achieve maximum preparation andcoordination. NTP 4 gives details of requiredinformation that must be included in a terminationrequest message.

The COMMAREA master station will assign ashore station for a ship’s termination circuit. Once theshore station has been assigned, both the ship and thestation may begin coordination to identify specificequipment keylists and frequencies needed to effecttermination. The shore station will also act as NECOS.Two hours prior to the scheduled termination, the shorestation can coordinate with the ship by telephone, localcircuitry, or by primary ship-shore.

When the ship shifts terminations, the securing ofthe current termination and the establishment of a new

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termination should coincide with a broadcast shiftwhenever possible. The ship must submit aCOMMSHIFT message.

Termination Types

There are six types of full-period terminations, asfollows:

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Single-channel radioteleprinter using eitherradio path or landline transmission media;

Single-channel low-data-rate satellite accessusing satellite transmission media;

CUDIXS special satellite access forNAVMACS-equipped ships using satellitetransmission media;

Multichannel radioteleprinter using either radiopath or landline transmission media;

Multichannel radioteleprinter using SHFsatellite transmission media; and

Tactical intelligence (TACINTEL) access forTACINTEL-equipped ships using satellitetransmission media.

Equipment Tests

To ensure that circuit equipment is in peakoperational condition, complete system back-to-backoff-the-air tests must be completed 24 hours prior totermination activations. Check cryptoequipment back-to-back after daily crypto changes and prior to puttingcircuits into service.

An aggressive PMS and quality monitoringprogram is essential. When checking equipment, lookfor power levels, scorch or burn marks, properoperation of interlocks, and cleanliness. When cleaningand inspecting antennas, look for cracks, chips, orblistering of insulators. Also check for deterioration,loose connectors, and correct insulator resistance.

COMMSPOT Reports

COMMSPOT reports will be submitted by allships, including nonterminated units, any time unusualcommunication difficulties are encountered. Ships willsubmit the COMMSPOT to the terminatingcommunications station. Timely submission ofCOMMSPOT reports is necessary to minimize furtherdeterioration of the situation.

Rules and general instructions for preparingJINTACCS formatted COMMSPOT reports are foundin the Joint Reporting System (General Purpose Re-ports), NWP 1-03, Supp-1 (formerly NWP 10-1-13).

PRIMARY SHIP-SHORE CIRCUITS

Primary ship-shore (PRI S/S) circuits are encryptedFSK/PSK teleprinter nets that permit ships to transmitmessages for delivery ashore. This service is availableto units that do not maintain a full-period ship-shoretermination. Navy tactical UHF satellites or theHF/UHF spectrum may be used to conduct ship-shorecircuit operations. Ships may use this circuit forcoordinating and establishing a full-period terminationwith the shore station.

T h e f r e q u e n c i e s f o r N C T A M S a n dNAVCOMTELSTAS that guard primary fleet ship-shore circuits are listed in applicable CIBs distributedby the COMMAREA master stations. Thesefrequencies are subject to change by the cognizantFLTCINC or by the NCTAMS.

OVER-THE-AIR TRANSFER (OTAT) ANDOVER-THE-AIR REKEY (OTAR)

There are significant vulnerabilities associated withthe handling of paper cryptographic material. Soundapplication of over-the-air transfer/rekey(OTAT/OTAR) procedures and techniques can reducethe amount of paper keying material required andreduce the potential for compromise. These proceduresand techniques are contained in the NAG-16BProcedures Manual for Over-the-Air Transfer (OTAT)and Over-the-Air Rekey (OTAR).

OTAT/OTAR also makes the transfer of keyingmaterial more responsive to rapidly changingoperational requirements. The use of NAG-16B wasdeveloped and verified by extensive use duringoperation Desert Shield/Storm. The specifiedprocedures served as an effective vehicle fortransferring keying to satisfy rapidly changing joint andNavy requirements. Expanded definitions, generalprocedures, and equipments are found in NAG-16B.

DISTRESS COMMUNICATIONS

Special methods of communication have beendeveloped to use in times of distress and to promotesafety at sea and in the air. Distress message traffic isbest described as all communications relating to theimmediate assistance required by a mobile station in

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distress. Distress traffic has priority over all othertraffic. All U.S. Navy communicators must be familiarwith distress signals to properly evaluate their meaningsand to take appropriate action when necessary.

If a ship becomes involved in a distress situation,communications personnel should send distressmessages on normal operating encrypted circuits. If theneed for assistance outweighs security considerations,the ship’s commanding officer may authorize thetransmission of an unclassified distress message on oneof the national or international distress frequencies.

When a ship in distress is traveling in company withother ships, the ship in distress will transmit the distressmessage to the officer in tactical command (OTC), whowill take appropriate action.

DISTRESS FREQUENCIES

Several frequencies in different bands aredesignated for the transmission of distress, urgency,safety, or search and rescue (SAR) messages. Thefollowing frequencies have been designated for useduring a distress or emergency situation:

500 kHz— International CW/MCW distress andcalling;

2182 kHz— International voice distress, safety,and calling;

8364 kHz— International CW/MCW lifeboat,life raft, and survival craft;

121.5 MHz— International voice aeronauticalemergency;

156.8 MHz— FM United States voice distressand international voice safety and calling; and

243.0 MHz— Joint/combined military voiceaeronautical emergency and internationalsurvival craft.

During SAR missions, the following frequenciesare authorized for use:

3023.5 and 5680 kHz— International SARfrequencies for the use of all mobile units at thescene of a search. Also for use of shore stationscommunicating with aircraft proceeding to orfrom the scene of the search. CW and voice areauthorized.

123.1 MHz— International worldwide voiceSAR use.

138.78 MHz— U.S. military voice SAR on-the-scene use. This frequency is also used fordirection finding (DF).

172.5 MHz— U.S. Navy emergency sonobouycommunications and homing use. Thisfrequency is monitored by all U.S. Navy ASWaircraft assigned to a SAR mission.

282.8 MHz— Joint/combined on-the-scenevoice and DF frequency used throughout NATO.

The control of distress message traffic on anydesignated frequency is the responsibility of the stationin distress. However, this station may delegate itsresponsibility to another station on the frequency.

Distress Watches

Navy units at sea have always maintained listeningwatches on distress frequencies. Communicationwatch requirements vary according to the operationalmission of the ship and available equipment assets.Ships in company normally divide distress watchrequirements among the group.

STATUS BOARD

The technical control of the shore station that isNECOS for fill-period terminations and PRI S/Scircuits must maintain a status board. The status boardshould indicate, as a minimum, all systems/circuits thatare active, tuned in, or in a standby status. It should alsoindicate all inoperative equipment. The watchsupervisors must verify the accuracy of the informationcontained on the status board at watch turnover andupdate while on watch. The status board must show thefollowing minimum information for active and standbycircuits:

Functional title of circuit;

Frequency(ies), both send/receive, if fill-duplexoperation is used;

Circuit designator, from communication plan;

Transmitter and receiver designations;

For shore stations, keying line designations;

Terminal equipment designation (for example,R-2368/URR #l);

Cryptoequipment, keying material, and restarttime;

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Figure 1-14.—AN/SSQ-88 Quality Monitoring Set and RCS interface.

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Figure 1-15.—AN/SSQ-88 equipment configuration.

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Operating position or remote control unitdesignation; and

Remarks, as appropriate.

QUALITY MONITORING

In recent years, the volume of communications hasincreased dramatically. This rapid expansion has led tothe installation of increasingly sophisticatedequipment. Such factors as frequency accuracy, dcdistortion, inter-modulation distortion (IMD), anddistribution levels are critical to the operation ofcommunications systems.

Satisfactory operation of these systems demandsprecise initial line-up and subsequent monitoring.System degradation is often caused by many smallcontributing factors that, when combined, render thesystem unusable. Simply looking at the page printer orlistening to the signal is inadequate.

Simply stated, quality monitoring is theperformance of scheduled, logical checks that willensure continuous, optimum performance and, in manycases, prevent outages before they occur. Somecommunications personnel quite often fail to realize thebenefits of quality monitoring. An attitude developsthat questions the need for quality monitoring. Theresult of this incorrect attitude is that circuits are eitherUP or DOWN. Personnel with this attitude perform noquality monitoring when the circuits are UP and are,therefore, forced to treat each outage as if it were aunique occurrence.

With no precise information concerning the trend ofthe system’s performance, personnel must jump fromone assumed probable cause to another assumedprobable cause, while valuable circuit time is lost. Aship with an aggressive quality monitoring programusually has personnel who are thoroughly familiar withall installed communications systems.

QUALITY MONITORING PROGRAM

The primary function of the quality monitoringprogram is the direct measurement of signal qualitycharacteristics, including:

Dc distortion;

Audio distribution level;

Frequency accuracy of RF signals;

Spectrum analysis; and

Loop current.

These measurements are broad categories and can bebroken down to specific tests for specific systems.

Quality Monitoring System

Figure 1-14 is a diagram of a quality monitoringsystem and RCS interface. The system was designed toprovide a means of monitoring and evaluatingperformance of any communications system used byforces afloat.

The monitoring system is a grouping of specific testequipments into a console designated as the AN/SSQ-88 Quality Monitoring Set. The set contains equipmentfor measuring and analyzing signals sampled by sensorsinstalled in each communications circuit interface. Thesystem should be operated only by personnel withsufficient knowledge to analyze the signals beingtransmitted and received via the ship’s circuits,including individual channels of the multichannelcircuits.

The console configuration shown in figure 1-15may not be compatible with all ships; however, mostships can use equivalent test equipment to establish aquality monitoring test system.

SUMMARY

Your commanding officer must be able tocommunicate with ships and shore stations to maintaineffective command and control of the situation at hand.Communications are, and always will be, the “voice ofcommand.” In the age of nuclear weapons, guidedmissiles, supersonic aircraft, and high-speed ships andsubmarines, top performance is required of our fleetcommunicators. You, as a Radioman, and yourequipment must always be in constant readiness to meetthis formidable challenge.

Distress communications are methods that havebeen developed for use in times of distress. Theyindicate the need for immediate assistance and havepriority over all other traffic. Various publications andlocal instructions will assist you in carrying out yourrequired responses to these situations.

Communication systems are periodically tested toensure that they operate efficiently and accurately. Thecombined tests, checks, and measurements helpdetermine the condition of systems, subsystems, andindividual equipments. Tests and measurements ofcommunication systems and equipments range from thevery simple to the very complex.

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