10 September 2000
Source: http://www.keesler.af.mil/81trss/qflight/AFJQS/AF2EXXX/HB202D.PDF

Cryptome mirror: http://cryptome.org/HB202D.PDF  (343KB)

[62 pages.]

Headquarters US
Washington DC 20330-1680

Air Force Qualification
Training Package 2EXXX-202D
1 October 1999

EI Tempest Installation Handbook

(2EXXX Communications-Electronics Specialties)

1. This Air Force Qualification Training Package (AFQTP) standardizes on-the-job training (OJT) and constitutes an approved training program for installation of Tempest equipment, cables, and grounding systems. The AFQTP is used to familiarize the El Team Chief and members with procedural installation of equipment requiring emission security controls.

2. Review Air Force publishing bulletins and AFIND8 to identify other available training materials. Use this AFQTP in conjunction with other applicable Job Qualification Standards UQS) or the Career Field Education and Training Plan (CFETP) and locally assigned tasks to identify work center duty positions. Also, use this AFQTP along with other applicable JQSs and the CFETP to evaluate newly assigned personnel and identify individual training requirements.

3. Submit recommended AFQTP improvements/corrections to the 81 TRSS/TSQS, 601 D Street, Keesler AFB, MS 39534-2229.



JOHN W. HANDY, Lieutenant General, USAF
Deputy Chief of Staff/Installations and Logistics

1 Atch

Supersedes AFQTP 2EXY-X, dated 21 May 1998



1 OCTOBER 1999

DATED 21 MAY 1998




About This Training Package

Chapter 1, Introduction to EMSEC

Chapter 2, Spacing

Chapter 3, Wire Way Installation

Chapter 4, Cable Installation

Chapter 5, Equipment Installation

Chapter 6, Grounding and Bonding

Chapter 7, Pre-Shakedown Inspection

Chapter 8, Team Chief Duties


This handbook is intended for use by Air Force Communications Electronic Engineering Installation (EI) personnel. It provides guidance on the installation of C-E equipment in an environment where emission security (EMSEC) is a consideration IAW RED/BLACK installation criteria. It is primarily designed for the inexperienced EI team member and Team Chief who are unfamiliar with TEMPEST-related installations. Team Chiefs who are familiar with EMSEC and RED/BLACK installation criteria can use the handbook as a reference guide and as a tool to train team members. This handbook does not deal with Standard Installation Practices. Rather it explains the fundamentals and concepts behind EMSEC and RED/BLACK installation criteria. Formal installation training is provided by each EI unit. EI trainers use AFJQS 2EXXX-202B, Standard Installation PracticesElectronics/Inside Plant, to plan, conduct, and document qualification training.

Contents of the handbook are NOT to be used as a basis for inspection or evaluation. This handbook is a specialized publication for familiarization and training purposes only; it is NOT a technical reference.


This training package was originally developed by TSgt Edward L. Hamilton and revised by SSgt Kevin Banks, 81 TRSS Qualification Training Flight, Keesler AFB, MS. The Training and Education Specialist was Mr. Tom Vuncannon. It was initially validated by 485 EIS, Griffis AFB, NY; 738 EIS, Keesler AFB, MS; HQ AFC4/DSS, Scott AFB, IL; and HQ AFCSC/SRM, Kelly AFB, TX MSgt Allen Thomas, 738 EIS, Keelser AFB, MS, was consulted as the Subject Matter Expert.

For more information on the 81 TRSS Qualification Training Flight and a list of other products that are available, feel free to visit our home page at http://www.keesler.afmil/81trss/qflight.




EMSEC is a short unclassified name referring to investigation and studies of compromising emanations and is comprised of TEMPEST, NONSTOP, and HIJACK. It also refers to those measures used to control compromising emanations. EMSEC is interrelated to the RED/BLACK concept which requires that electrical and electronic components, equipment, and systems processing classified plain text information be kept separate from those that process encrypted or unclassified information. The whole idea of EMSEC and RED/BLACK concept is to prevent or reduce the effects of compromising emanations.

Compromising emanations (CE) are unintentional, intelligencebearing signals which, if intercepted and analyzed, disclose classified information transmitted, received, handled, or otherwise processed by any information-processing equipment.


Emanations are unintended signals or noises appearing external to C-E equipment as information is being processed. Every electronic or electromagnetic device, whether or not designed as a transmitter gives off some electromagnetic signals or emanations. Proper design minimizes emanations given off by a device, but some will always be present.

When a device processes voice or data, it may "leak" information through emanations. An example would be "cross-talk" on telephone lines where signals leak from one line to another and another person's voice intrudes on your phone call. If strong enough, information-bearing emanations may travel through the air, plumbing, wires, and ventilation systems to areas where enemy agents could recover them. If the signals contain classified information and are intercepted, this information may fall into enemy hands. The potential for compromise exists wherever classified information is processed.

A radio can produce emanations. Does this fall under compromising emanations? Not necessarily. If you remember, compromising emanations refer to classified signals. Most radios that transmit classified information carry encrypted signals. In order for emanations to be compromised, they must be carrying classified information that is not yet encrypted. If the emanations are not carrying classified information or have already been encrypted, then they are not compromising emanations.


Let's take a look at some of the terms used with EMSEC. EMSEC has a language unique to itself. The following are some of the EMSEC-related terms you should be familiar with.


Information that's been determined, pursuant to Executive Order 12356 or any predecessor order, to require protection against unauthorized disclosure and is so designated. This includes all classified and/or sensitive information as set forth in 10 U.S.C. Section 2315 (Warner Amendment). The Warner Amendment applies to information which is unclassified but which involves intelligence activities, cryptologic activities, command and control of military forces, weapons systems, or is critical to the direct fulfillment of military or intelligence missions.


As it pertains to C-E equipment, transmission lines, and associated wiring, BLACK signifies both physical and electrical areas where data/voice signals are encrypted or unclassified and therefore relatively safe from compromise.


As it pertains to C-E equipment, transmission lines, and associated wiring, RED signifies both physical and electrical areas where classified data/voice signals are in plain text (unencrypted) and highly susceptible to compromise.


The RED/BLACK concept requires electrical and electronic circuits, components, and systems which handle classified unencrypted information (RED) be separated from those which handle encrypted or unclassified information (BLACK). Under this concept, RED and BLACK terminology is used to clarify and to differentiate between circuits, components, equipment, and systems. The terminology also differentiates between the physical areas in which they are contained.


The complete building or facility area under direct physical control that can include one or more limited exclusion areas, controlled BLACK equipment areas. or in any combination.


BEA is an area in a CAA which contains equipment processing unclassified information or encrypted information.


An REA is the space within a CAA which is designated for installation of RED information processing equipment. It also includes associated power, signal, control, ground, and distribution facilities.


A CBEA is a BLACK equipment area not within a CAA, which is afforded entry control at a security level commensurate with operational requirements. Examples of CBEAs are technical control facilities and radio relay sites supporting CAAs.


An ERTZ is that area or zone established as a result of determined or known equipment radiation characteristics. The zone is a three dimensional space within which a successful hostile intercept of compromising emanations is possible. The ERTZ normally would be associated with equipment in an REA.


COMSEC equipment provides security to telecommunications by converting information to a form unintelligible to an unauthorized interceptor and, subsequently, by recovering such information to its original form for authorized recipients. COMSEC equipment also includes equipment specifically designed to aid in, or is an essential element of, the conversion process. COMSEC equipment includes crypto equipment, crypto ancillary (synchronization) equipment, crypto production (equipment used to produce or load keying material) equipment, and authentication equipment.


A wireline or fiber-optic telecommunications system that includes terminals and adequate acoustic, electrical, electromagnetic, and physical safeguards to permit its use for the unencrypted transmission of classified information.


A grounding grid which provides a low-impedance path for signals and currents to return from the load, back to the generator. This system overcomes the limitations of the older single shunt grounding systems which are more inherit to noise and increased use of filters.

Now that the definition of EMSEC and its associated terms has been discussed, let's take a look at how compromising emanations are generated.



A high level device is any device that uses a high level of energy; i.e., voltages greater than 6 volts and current levels greater than 20 milli amps for its normal operating mode. This is a potential EMSEC hazard because higher levels increase the potential for compromising emanations. As an example, teletype equipment operating above +6 volts, as specified in MIL-STD-188. is considered a high level device.


A low level device is any device that uses low level signaling. This is a current driven signal, ±2 volts at 70 micro amps or a voltage driven signal, ±6 volts.


Extremely fast switching action involved in transistor and diode operations produces sharp rising pulses. These are desirable from an equipment design and operational viewpoint, but are very undesirable from an EMSEC viewpoint. Fast rise and fall times, or rapid transitions, produce compromising emanations.


Coupling through grounds can take place directly and also through currents circulating around and between physically separated grounds. RED emanations cannot be picked up and transmitted on a BLACK ground if the RED ground is properly installed.


When performing a test or alignment on RED and BLACK equipment, use caution to prevent test leads or probes from coupling the RED and BLACK equipment together. This can allow the classified unencrypted information from the RED equipment to be transferred to the BLACK equipment. This is a security compromise.


There are sensitive components in the handset and the ringing element of a telephone. They can easily be activated by signals unintentionally emitted from RED/BLACK equipment. These signals can be picked up and transmitted by a telephone, even when the phone is on hook.

As one can see, there are many ways compromising emanations can be transmitted or coupled. The following procedure helps reduce the risk of compromise to an acceptable and affordable level.


The EMSEC countermeasures review is not performed by El but by the Base EMSEC Manager; however, we'll discuss it here to familiarize you with overall aspects of EMSEC.


An EMSEC countermeasures review is the procedure used to determine the appropriate level of required NONSTOP or HIJACK countermeasures for a facility, system, or equipment that processes classified information. It is a two step process:

Installation standards are determined by the Base and MAJCOM IP office which provides inputs to the project engineer. This information is passed down to the El Team in the Project Package. Let's take a look at RED/BLACK equipment installation concepts.


It's important for all Ei team members to closely follow basic RED/BLACK installation concepts and prevent TEMPEST violations. Let's examine the purpose and goal of the RED/BLACK installation concepts.


The purpose of RED/BLACK installation concepts is to ensure standardized installation practices are used for RED equipment, BLACK equipment in a RED area, and associated wire line runs. If standard guidelines are not followed, RED processing areas could have equipment installed in such a manner as to invalidate their use as a RED processor and create a TEMPEST hazard.


The goal of RED/BLACK equipment installation concepts is to create physical, electrical, and electromagnetic (EM ) barriers around equipment that processes National Security Information (NSI), and to prevent that information from being exploited by hostile intelligence activities. Design begins by establishing an REA within the CAA. The space is established to contain the RED processing equipment and related support functions with barriers to exclude all other non-related functions. The REA is sized according to separation tables and ERTZ data.


A factor that also affects installation concepts is the type of equipment. C-E equipment that isn't TEMPEST approved is installed differently than TEMPEST approved equipment. But what kind of C-E equipment is not TEMPEST approved?

C-E equipment not TEMPEST approved is RED equipment that does NOT meet the criteria of NSTISSAM Laboratory Test Requirements and Electromagnetics. This will be discussed in Chapter 8, under the Project Review section.


In the RED/BLACK installation standards you'll also run across references to Electromagnetic Pulse (EMP). EMP is a high energy element resulting from a nuclear blast that can be induced into electronic equipment and lines causing component destruction. Let's stop and take a look at the difference between EMP protection and EMSEC protection.


The difference between EMP and TEMPEST in RED/BLACK standards are levels, protection, and grounding paths.

Now that you know how EMSEC countermeasures are assessed and have a basic knowledge of RED/BLACK installation concepts, let's examine EMSEC countermeasures.


Two of the most effective methods of containing compromising emanations are physical placement of conductors and use of shields. Later chapters go into more detail with these and other countermeasures.


Current can be induced into a wire located near the wire carrying the original current. The amount of induced current depends on several variables such as distance and mutual angles between conductors, as well as the level of original current.

The easiest variables to control are the distance and the mutual angles. Because the intensity of the electromagnetic field surrounding a conductor gets weaker as the distance from the conductor increases, there is less induced current in wires that are widely separated than in wires close together. Also, wires at right angles to each other have minimum mutual induction. Therefore, you must always comply with RED and BLACK conductor separation specifications.


The purpose of shields is to reduce the coupling of electrical or magnetic fields into or out of circuits through the use of Electromagnetic (EM) barriers.


EM barriers must contain any compromising emanations produced by information processing equipment and exclude EM disturbances whether natural or man-made. They consist of perimeter barriers and internal barriers.


The effects of an electromagnetic field produced by a current passing through a wire is reduced in free space, but in many cases, not enough to reduce the radiated signal to a safe level. Cable shields, both nonferrous and ferrous, provide high attenuation to the radiated fields. The cable braids form a nonferrous shield which attenuates electrical radiation. Ferrous material is more effective at higher frequencies and used primarily as a magnetic field shield.

shielding of signal cables is enhanced by filtering all signal lines which connect RED and BLACK equipment. All cable shields should be terminated to the signal ground or equipotential plane via low impedance paths. RED and BLACK signal and shield grounds should be kept electrically separated until they reach the equipotential ground plane. Convenient electrical fault grounding points, such as conduit, metallic wire ways, enclosed equipment racks, and in some cases, shielded rooms are not to be used for signal grounds.

Shielding methods vary depending upon the type of equipment, physical construction of facility, and hardening requirements for EMP. TEMPEST approved equipment which uses low-level balanced voltage digital signals, shielded cables, and has adequate built-in power and signal/control line filters may not require use of conduit or duct. As a minimum, however, nonferrous shielded cable should be used. Use of conduit or duct as cable shielding is dependent upon the EMSEC assessment and local environment. Filters may also be used and may be required by EMSEC guidelines to suppress emanations at their source. Low level keying and equipment that operates at the same or lower voltage/current levels as associated equipment can also be used. But what about the facility itself?


Shielded enclosures are hardened facilities designed to negate EMP threats. They are shielded to prevent EMP damage to equipment and provide EMSEC protection. Inside the facility there are different security and shielding requirements.


Different areas of the facility are rated for physical security. The physical location of the equipment determines whether an escort is required for the installation team. The most secure area you'll work in is the REA. Escorts to secure areas are provided by the customer unit.


Facility shielding requirements are found in AFSSM 7011. A facility may be totally shielded in a self-contained unit or may be part of a two-sided shield.

As an EI team member, you do not install shielded facilities. This is the responsibility of allied support. However, being knowledgeable of the shielding requirements in your work area can help to bring about security consciousness. This security consciousness will aid you throughout the installation in being aware of potential compromises and discrepancies that can develop into security problems.


To properly install C-E equipment in RED/BLACK areas, you must be familiar with EMSEC installation concepts and standards. The information in this chapter is your first step in becoming familiar with these critical requirements. Future chapters cover specific unclassified TEMPEST installation techniques in more detail.

Learn all you can about EMSEC before the installation begins. You, and the Base EMSEC Manager are the key to controlling and preventing compromising emanations.



Spacing between equipment and transmission lines is a critical factor in preventing compromising emanations. As an El installer you must be aware of and adhere to spacing requirements identified in your project package and other directives. In this chapter, we'll discuss bow RED/BLACK spacing requirements apply to installation standards. As you may recall, ERTZ (Equipment Radiation TEMPEST Zone) is the projected distance from equipment and transmission lines that compromising emanations can travel. Equipment and transmission line spacing requirements, based upon the ERTZ, are designed to minimize reception of compromising emanations. Let's first examine how equipment characteristics influence spacing standards.


Basically, three equipment characteristics influence spacing standards: 1) the equipment designation (RED or BLACK), 2) whether or not the equipment is TEMPEST approved, and 3) signaling levels.


C-E equipment is designated RED or BLACK according to the type of traffic it processes. The RED or BLACK designation is a major factor in establishing equipment spacing restrictions. For example, maximum distance is desired between RED and BLACK equipment. Why? Remember, RED equipment carries unencrypted classified information. If located too close to a piece of BLACK equipment, the classified emanations from RED can be picked up and transmitted by the BLACK. Spacing requirements between equipment with the same designation (BLACK-BLACK or RED-RED) are not as stringent. Another spacing determinant is whether or not the equipment is TEMPEST approved.


RED communications equipment that does not meet the criteria of NSTISSAM TEMPEST/1 -92 (C), Compromising Emanations Laborator Test Requirement Electromagnetics (U) is not Y TEMPEST approved. This means it has not been specifically designed with protection against compromising emanations. Therefore, spacing requirements are greater than for TEMPEST approved equipment.


A high level device is any device that uses a high level of energy, i.e., voltages greater than 6 volts and current levels greater than 20 milli amps for its normal operating mode. For example, teletype equipment operating above +6 volts is considered a high level device as specified in MIL-STD-188. This is a potential TEMPEST hazard and requires greater equipment spacing than for a low level device. A low level device is any device that uses low level signaling. This is a current driven signal, ±2 volts at 70 micro ampere or a voltage driven signal, ±6 volts. Now let's discuss some specifics of equipment spacing.


We'll consider specific unclassified equipment spacing requirements based upon equipment characteristics. Keep in mind that actual separation requirements for a particular system end item of equipment is classified CONFIDENTIAL.


This figure shows a single-line secure teletype system using TEMPEST approved equipment. Dissimilar RED equipment, such as the teletype and the switch bay, are separated by at least 2 inches (50mm). The separation distance may increase due to specific installation practices such as minimum cable bending radius of the sizes of interconnecting ducts and conduits. The separation distance cannot be less than that established IAW RED/BLACK standards listed in MIL-HDBK-232A, Table 11, NACSIM 5203, Table 3- 1, and applicable CM tables in AFSSI 7002. Improper spacing distances could result in a TEMPEST hazard. [See original document for figures.]


Figure 2 - 1, Non-TEMPEST Equipment Spacing, shows a small single-line teletypewriter facility using non-TEMPEST approved, high-level equipment. In this type of installation, the COMSEC equipment establishes a reference for equipment separation. All RED equipment, including distribution frames, are separated from the COMSEC equipment by at least 3 feet (0.9m). Why? Because emanations from the RED equipment can be picked up and transmitted by the COMSEC equipment, though the COMSEC equipment itself is secure. All BLACK equipment is also separated from the COMSEC equipment by 3 feet (0.9m) resulting in a separation of 6 feet (1.8m) between high level RED and BLACK equipment.

[See original document for figures.]

Figure 2-1, Non-TEMPEST Approved Equipment Spacing

For Patch and Test facilities, each RED patch panel is separated from the BLACK patch panel by a distance greater than the longest available patch cords. An alternative method is to use dissimilar patch facilities for RED and BLACK. This is to prevent accidental cross patching between RED and BLACK systems.


Low level BLACK data processing equipment must be installed a minimum of 3 feet (0.9m) from RED data processing equipment. For BLACK voice equipment (i.e., administrative telephones) the separation distance must be a minimum of 3 feet (0.9m). More information about low level spacing requirements is found in MILHDBK-232A, Table 1, NACSIM 5203, Table 3-1, and the applicable CM tables in AFSSM 7011.

In addition to spacing requirements, all TEMPEST approved equipment should be located at least 3 feet (0.9m) from the walls to provide room for technical inspections and maintenance.


Just like equipment which is not TEMPEST approved, high-level devices require a minimum separation distance of 6 feet (1.8m) between BLACK and RED equipment. All RED equipment, including patch panels and distribution frames, must be separated from COMSEC (encryption devices) equipment by at least 3 feet (0.9m). More information about high-level spacing requirements can be found in ML-HDBK-232A, Table 11, NACSIM 5203, Table 6-1, and the applicable CM tables in AFSSM 7011.


Voice systems (telephone systems) installed in secure areas are designated either RED or BLACK. The one that's presently in use is the Secure Telephone Unit (STU III).


Wire way is a term used to describe conduits, duct work, or other structures used to carry cabling or wiring. Installation of wire ways is covered in AFJQS 2EXXX-202B, SIPT Electronics and Inside Plant. What we're now interested in are the basic wire way spacing requirements.


Spacing requirements for wire ways are determined by their designation (RED/BLACK), how they are positioned (parallel/perpendicular), and the equipment operating level (high/low).


Separation requirements are listed in various publications, to include MIL-HDBK-232A, NACSIM 5203, Preferred Products List (PPL), and the TEMPEST Profile Data List (TPDL).


MIL-HDBK-232A, RED/BLACK Engineering Installation Guidelines, contains unclassified spacing requirements for RED/BLACK installations. It is available from the Base EMSEC Manager.


NACSIM 5203, Guidelines for Facility Design RED/BLACK Installation, is classified CONFIDENTIAL. It contains classified spacing requirements. It is also available from the Base EMSEC Manager. As an El team member, you may not need to use it, but
knowledge of its contents may be useful during an installation. Contact the Base EMSEC Manager for access.

AFSSM 7011

The Emission Security Countermeasures Review. It provides guidance for making the emission security countermeasures review and spacing requirements for the control of compromising emanations, NONSTOP, and HIJACK.


This is a listing of equipment which meets NTISSAM TEMPEST 1-92 design standards for approved TEMPEST systems. It is also available through the Base EMSEC Manager. It is of more importance to a Team Chief; therefore, we'll discuss its contents in Chapter 8, Team Chief Responsibilities.


This publication provides power requirements and physical control space for equipment not meeting NSTISSAM TEMPEST 1-92 design standards. It is classified CONFIDENTIAL and available through the Base EMSEC Manager.


Proper equipment and cable spacing is required if you are installing equipment which must meet EMSEC approval. When installing CE equipment in areas where classified information is being processed, be sure to check your project package against the appropriate spacing standards. Become familiar with spacing requirements and comply with them during every step of the installation.

Spacing requirements for equipment in a classified environment are determined by equipment characteristics. This includes the designation of equipment (RED/BLACK), whether the equipment is TEMPEST approved or not, the classification of information being processed, and the equipment signaling level. In some cases, the type of equipment is also taken into consideration when determining spacing requirements, i.e., separate RED and BLACK patch and test facilities or secure voice terminals. The routing of wire ways also has a bearing on spacing requirements. Spacing for RED and BLACK wire ways differs for parallel routing and perpendicular routing. Spacing information is found in MILHDBK-232A, NACSIM 5203, and AFSSM 7011. An Approved Products List and TEMPEST Profile Data List can provide useful information about unique equipment characteristics. Proper spacing of equipment and wire ways in a RED/BLACK installation minimizes the effects of compromising emanations and provides a secure environment. This is the goal of the installer in a classified environment. In the next chapter, we will discuss wire way installation.




Properly fabricated and correctly installed wire ways are helpful in reducing compromising emanations. All transmission and power lines radiate portions of the signals they carry. Therefore, it's necessary to encase unencrypted data lines and unfiltered power lines in a bonded shield to prevent interception of classified information. This chapter addresses installation of shielded wire ways to reduce compromising emanations. Topics include shielding requirements, principles of wire way installation, and how to mask wire ways. Proper wire way installation will greatly reduce the potential of comprising emanations.

As an EI team member, you must practice accepted installation techniques. This includes grounding and bonding all cases, cabinets, racks, conduits, and wire ways. You also need to ensure shield integrity by eliminating all openings through which compromising emanations can escape. This is done by making sure all panels, covers, and floors are properly installed.


Metallic wire ways and conduits provide shielding for the cables they contain. Let's look at the unique requirements for conduit, duct, and junction boxes.


Cables for equipment or systems designed to operate in the highlevel mode are installed using one overall nonferrous shield and ferrous conduit with compression or trawled fittings or ferrous cable duct. All RED and BLACK signal, control, and power lines, as well as all lines which are not a part of the communications system (door bells, administrative telephones, fire alarms, etc.), are encased in separate conduits or ducts.

Properly installed conduit with appropriate coupling devices provide an adequate shield. Conduit is not required for secure voice terminal wire ways if there are no other electronic devices in the general area. If a telephone is located remote from the terminal, the interconnecting cable should be installed in ferrous conduit.

Flexible conduit may be used for short runs, not to exceed 3m, between wire ways or junction boxes and equipment. However, do not use flexible conduit which contains plastic or non-conducting bushings in fittings. This interrupts shielding continuity.


All junction box apertures must be closed by conduit or ferrous aperture covers. Use RFI gasket material to ensure a complete seal against emanations.

Now that you are aware of basic conduit, duct, and junction box shielding requirements, let's examine TEMPEST wire way installation principles.


Proper wire way installation reduces the likelihood of magnetic fields interfering with equipment by creating an electromagnetic barrier. The barrier stops free space radiation from coupling onto power or signal lines. Most wire ways enter a secure facility through a common facility entry point. We'll look at entry points in more detail in a future chapter. All you need to know now about the facility entry point is that it's found on the floor plan drawings and is used as the primary point to determine routing of facility wire ways. Now let's take a look at wire way installation techniques.


When possible, wire ways are installed where they can be physically observed within the facility for security purposes. However, facility construction and equipment layout do not always permit surveillance of all wire ways. Open wire ways must pass through walls, floors, or ceilings in the Controlled Access Area (CAA). RED distribution facilities and wire ways should always be exposed to view in the CAA except when passing through floors, walls, or ceilings to other spaces in the CAA. A nonconductive break in the wire way may be rewired at the CAA boundary with the CAA side bonded to the appropriate ground. Wire ways can be permanently installed within the walls, under the floors, or above the ceilings under the following conditions:

1. Conductors are monitored.

2. Accessibility is only from within the CAA.

3. Alarmed barriers are provided to prevent undetected human penetration.

4. Protected Distribution System (PDS) standards are complied with IAW AFSSI 3030, Protected Distribution Systems.

Protected Distribution Systems (PDS). PDS requirements are applied when RED cable distribution must leave a CAA and go through a less secure area before entering another CCA.

Security standards. The degree of required security depends upon the level of classification of the information, security level of areas crossed, and responsiveness of security force. Certain PDS classes and installations require rewiring alarms or visual surveillance. Surveillance requirements vary depending on PDS classes, physical locations, installation techniques, and type of data/information passing through the PDS.

Installation standards for PDS. Portions of the PDS are normally exposed to surveillance. All joints and covers are welded and pull boxes and accesses kept to a minimum. Where pull box access is required, covers are equipped with approved locks and intrusion detection devices. All junction or terminal boxes should be equipped with an RFI (Radio Frequency Interference) gasket cover.


To install BLACK wire ways, follow the guidelines in TO 31-10-12, (Metal Ducts and Conduits), Sections II and III. Guidelines for running RED wire ways are found in NACSIM 5203 (Guidelines for Facility Design and Red/Black Installation) and AFSSM 7011 (The Emission Security Assessment).

Conduit/Duct. Where positive batteries between RED and BLACK runs are necessary and extra physical protection is required, use totally enclosed ducts and conduits. RED and BLACK cables are never run in the same conduit or duct except in special cases. Separate RED and BLACK power distribution facilities need not be provided in a CAA where only low level signaling and TEMPEST approved equipment are utilized. In this case all power in the CAA will be considered BLACK, and RED information processing equipment can be connected directly to the same power.

When installing wire ways, remember to use the proper spacing distances discussed in Chapter 2. Also, if ducts/conduits must cross, ensure the crossings are perpendicular. Ducts and conduits should be grounded and unpainted to provide electrical continuity and all sections and covers firmly bonded. Use RFI gasket material withjunction box covers to ensure a complete seal against emanations.

Technical and non-technical power is distributed in separate ducts/conduits. BLACK processing equipment or utility equipment will not be powered from filtered power panels. To do so could allow classified (RED) emanations from the filtered power panel to be picked up and transmitted on the unclassified (BLACK) wire ways. TO 31-10-24 (Grounding, Bonding and Shielding), Chapter 8, and MIL-HDBK-232A, cover installation of BLACK power panels in more detail. MIL-HDBK-232A, NACSIM 5203, and AFSSM 7011, cover specific installation criteria for RED power panels.


All signal, power, and ground lines, components, equipment and systems within or serving a CAA which handle classified signals of modulation should be distinctly marked with red tape or paint at intervals of approximately 1.5m. An exception is conduit carrying RED signal ground feeders outside the building in a controlled area. All of the following cables should be marked RED.

1. Those carrying NSI.

2. Those between the encrypted side of crypto equipment and individual subscriber set or terminal equipment.

Wire ways that are not a physical element of the C-E processing system are identified as BLACK and not normally marked. This includes utilities such as smoke detectors, thermostats, etc. When BLACK components are very few, they may be distinctly marked with a 1 inch wide strip of black tape or paint at 5 foot intervals instead of marking RED components. On components colored black, another color such as white may be used to accentuate the black tape or paint.


Proper installation of shielded cable, conduit, duct, and junction boxes is required to prevent compromising emanations and qualify the facility as TEMPEST approved. Basic installation techniques identified in the 31-10-series TOs apply. However, you must comply with the additional shielding measures and hardware locations specified in MIL-HDBK-232A, NACSIM 5203, AFSSM 7011, and AFSSI 3030. Your project package should specify, in clear terms, precisely how to install TEMPEST approved wire ways. Be sure to follow the package and guidelines provided in the applicable references. The next chapter addresses the distribution of cabling in the newly installed wire ways.



To meet TEMPEST specifications and further reduce the potential of compromising emanations, you must always comply with specific cable installation standards. Cables must be protected and shielded throughout the facility from the point of entry to their final termination point. Any break in shielding or incorrect routing could result in radiation of compromising emanations.

This chapter addresses requirements for installing cables in secure areas. This takes into consideration shielding, routing, equipment types, and wire terminations. We'll also discuss the purpose of filters, their application, and their basic installation techniques. The information in this chapter, along with guidance in your project package, the 31-10-series TOs, NACSIM 5203, and AFSSM 7011, will prepare you to meet TEMPEST installation standards in secure facilities.


Prior to actually installing cables and signal lines you must be familiar with basic secure area cable routing, shielding, crossconnect and termination requirements. Factors which affect the degree of emanations given off by a cable include the type of cable and the methods of cable termination and cross connection. The type of equipment and signal levels also influence how wire lines are installed. Cable shields provide very effective emanation suppression.


Fiber optic systems should be used in place of metallic cables whenever possible and when cost effective. They have several EMSEC advantages over conventional metallic cables.

Installation standards for fiber optic systems are not the same as those for conventional metallic cables. The installation standards are:


A basic EMSEC requirement is each cable in a secure facility should have at least one overall nonferrous shield, such as the shield on a multi-pair cable. When TEMPEST approved equipment is used, signal cables with at least one overall nonferrous shield can be installed using cable ladders and trays. Unshielded wiring must be installed in totally enclosed duct and conduit. For equipment operating in the high level mode, all cables, shielded and unshielded, must be installed with ferrous conduit with compression or threaded fittings or ferrous cable duct.

Cables with overall nonferrous shields are used for RED signal and cable lines and also for BLACK lines. The shields of all cables within a RED equipment area (REA), BLACK equipment area (BEA), and controlled access area (CAA) are grounded at one end. Neither cable shields nor ground conductors will be used as a return path for RED signal, clocking, or control signals. Shielding requirements for BLACK cables are listed in MIL-STD-188-124A. Shielding requirements for RED cables are in NACSIM 5203 and AFSSM 7011. There are two types of control/signal cables used for TEMPEST installations: twisted pair and coaxial.


All signal and power lines enter and exit a secure facility through two separate entry points located in the cable and power entrance vault. Vault access is restricted to maintenance personnel with the required security clearance.

Complete accountability of all wires and cables within or passing through a secure area will be clearly marked, labeled, or tagged according to purpose. Unused wiring in cables will be grounded within the controlled areas and clearly marked as such.

The specific use of each telephone conductor is accounted for at the point of entry. This is done by labeling or log/journal entries. This accountability also applies to unused conductors terminated at the point of entry and connected to appropriate connector blocks.


As mentioned earlier, the type of processing or equipment being installed also affects cable installation requirements. Some examples of equipment and installation requirements are:


Proper terminations with a minimum of signal loss are required for TEMPEST installations. Shields will be continuous, low resistance runs by proper termination of all joints and splices. Terminate to signal ground at one end only. Shields should not be connected to equipment cabinets; make the cable shield common to AC protective grounds.

Cable shields should be tightly fastened to the cable connector shell with a compression or soldered connection. When assembling a connector, the cable shield must be less than 1 inch (2.5cm) from the point where it breaks away from the individual shielded conductors of the cable. A distance of more than 1 inch (2.5cm) increases the potential of compromising emanations. If a pigtail is the only method of shield termination that can be used, it should be as short as possible and terminated at one end only. Proper grounding of cable shields allows the shortest possible exposure of unshielded pairs and provides a minimum impedance path to the equipotential ground plane.

As shown in the illustration to the right, there are three basic methods of terminating wire lines. More than likely, specific termination requirements will not be addressed in your project package. The Team Chief must use the method that conforms to existing standards. [See original document for figures.]

Wire wrap is considered the most reliable type termination. Solder lugs are prone to cold solder joins causing a mismatch of impedance. The Type 66 Connector Block makes fast connections to terminals without removing the conductor insulation.


Cross connects are used in DFs to connect incoming and outgoing wire lines to modems, modems to COMSEC devices, and COMSEC devices to terminal equipment. The color code for Secure System cross connects is found in TO 31-10-2, Table 3-14.


Filters are often installed in both power and signal lines. Combined with shielding, they suppress most compromising emanations generated by equipment.


Filters are used to pass desired audio and RF frequencies to the load while shunting unwanted frequencies either to ground or back to the source. Their use is determined by the Project Engineer.

Often, control signals associated with a channel are generated in the RED area and must be routed to the BLACK area for control of channel functions. If such signals are routed in the same cable as RED cable signals, they are considered RED. Isolators are often incorporated at the RED/BLACK boundary for these signals.


Within the facility, a RED/BLACK boundary is required for signal lines which must transverse both areas but do not pass through COMSEC devices. This is achieved by using an isolator. The most commonly used isolator is the Optical Isolator.


Following proper installation methods, including routing, shielding, and termination of wire lines, will reduce the effect of compromising emanations in a secure area. Fiber optic systems are much more secure than metallic cables and should be used whenever possible. By following the RED/BLACK installation criteria for wire lines and filters, the installation team is on its way to providing secure communications with no signal compromise. The next chapter introduces you to C-E equipment IAW RED/BLACK installation criteria.



Proper installation of COMSEC and associated processing equipment is a major factor in reducing compromising emanations. When installing RED and BLACK equipment in secure facilities, you must follow the procedures in TO 31-10-29, Erection and Assembly of C-E-M Equipment. In addition, you must adhere to RED and BLACK TEMPEST criteria which should be clearly defined in your project package. This includes compliance with equipment spacing requirements discussed in Chapter 2 and other requirements identified in MIL-HDBK-232A and other directives.

This chapter identifies various types of RED equipment and basic installation criteria applied to each type. For the most part, the information contained within was extracted from MIL-HDBK-232A. Having a basic concept of RED and BLACK equipment installation criteria before you start the installation will assist you in completing project reviews and give you an idea of the TEMPEST installation standards you must comply with.


Any device that processes classified information is considered RED equipment. For example, commercial telephones coupled with cryptographic devices can be configured as secure voice switching systems in RED areas. In such cases, the telephone is a RED device. Word processors, as well as mainframe computers or facsimile (FAX) machines, may also be used as RED devices. Even the common electric typewriter can be a RED device. While numerous types of equipment which process classified information can qualify as RED equipment, you need to be familiar with the more common types of RED C-E equipment which you may be installing in telecommunications centers. This includes such items as teletypewriter, secure voice systems, facsimile, video devices, patch panels, ancillary equipment, and storage devices.


Most of the secure voice systems in use today interface with specially designed telephone instruments and/or data and facsimile terminals. A RED telephone network must be totally contained within the CAA but may have trunks coupled to the central office if the trunks are encrypted.


There are two basic types of facsimile devices, analog and digital. The older analog devices operate at lower speed and require an analog to digital conversion prior to encryption. The newer digital devices do not require signal conversion. No matter which type is used, shielding, filtering and separation requirements still apply.


Computer systems range from small stand-alone word processors to moderate-sized RED digital computerized telephone switches.


When video devices are used as RED processors, they are usually installed in areas where the entire video distribution is confined to a building or small group of buildings. However, there are still grounding, bonding, and shielding requirements for all cables within the video system.


Storage devices include components in which classified information is stored, such as magnetic memory in recorderreproducers and computer memories. The RED/BLACK considerations for both on- and off-line devices are the same.


Ancillary equipment includes such devices as analog to digital and digital to analog converters, line controller units, crypto-bypass devices, line drivers, rate converters, rate buffers, synchronizers, and other units required between the user terminal and the Encryption device.



Based on connectivity considerations and physical restraints, BLACK equipment is normally grouped together near the Main Distribution Frame (MDF). RED equipment is grouped together and installed some distance away (as directed by separation requirements) from the BLACK equipment and the MDF. Crypto equipment is normally located somewhere between the BLACK and RED equipment. Depending upon the size of the facility, physical layout, and amount of equipment, there may be more than one REA, BEA, and crypto area. One of the main concepts of equipment layout is to group related equipment together and minimize cable length. Shorter cable runs reduce the probability of emanations and interference.


BLACK equipment is not normally installed in RED equipment areas. When it must be, strict compliance with the spacing requirements identified in Chapter 2 is required to reduce the possibility of BLACK equipment picking up emanations from RED equipment.


All signal cables are routed to the MDF. Intermediate Distribution Frames (IDFs) are normally installed in close proximity (RED IDF near RED processors; BLACK IDF near BLACK equipment) to the equipment they serve. All RED and BLACK distribution frames are separately installed and enclosed in a CY-597, CY267S, or equivalent cabinet.

For further information on equipment layout, refer to MIL-HDBK-232A and your project package. If, during the early stages of an installation you identify perceived equipment layout problems, notify your Team Chief and get in touch with the project engineer.


To further reduce the effects of compromising emanations, certain installation precautions must be taken when installing both RED and BLACK equipment in secure facilities.


Patch panels are used to test and monitor circuits and substitute equipment or lines when failures occur. Patch panels in patch and test facilities are primarily used to restore and route VF and digital circuits. There must be no means of patching directly from the RED side to the BLACK side or among isolated RED patches. This is accomplished by physical separation, dissimilar patching, dissimilar wiring, and dedicated switching.


To reduce possible compromising emanations, all rack-mountable RED processing equipment and ancillary equipment is installed in cabinets. The equipment should make bare metal contact with the cabinet. Blank panels are installed on front of all unused cabinet spaces. When properly installed, the panels and closed cabinet doors greatly reduce undesired emanations. Make sure you have a sufficient number of blank panels available. An exception would be RED patch panels with low-level circuits. In this case, front covers are not required.


These are normally known as recorders/reproducers in voice communications. They are also used as memory storage units for computer systems. Avoid the common installation practice of removing cabinet sides of a group of units and bolting the chassis together to form a single unit since this arrangement negates the shielding effectiveness of the cabinet. To follow proper RED/BLACK installation criteria, install each unit as a stand-alone device with individual grounding and bonding.


Radio equipment is not normally installed in secure areas which have TEMPEST restrictions. This is to prevent transmission of classified data or voice. Sometimes, however, radios must be installed within CAAs to support command posts and other specialized operations. In such cases, all microphones and handsets located in REAs are equipped with Push-To-Talk (PTT) and Push-To-Listen (PTL) switches. To safeguard against accidental transmission of classified signals, audio and RF transmission lines are encased in dedicated conduit and equipped with bandpass filters located at the facility entrance plate.


The final communications equipment installation step is proper marking of equipment
designations. TO 31-10-27, Standard Installations Practices Equipment Designations, is used in marking designations on ground C-E equipment. This includes floor plan positions and group designations. RED information processing equipment will normally be marked with a 1" x 3" red tape or paint mark near the equipment nomenclature label. TSEC nomenclatured material will not be marked. If BLACK components in the CAA are very few, they may be marked instead of RED components. NACSIM 5203 and AFSSM 7011 contain other guidance for marking RED equipment.


Proper installation of equipment IAW the 31-10-series TOs, MIL-HDBK-232A, NACSIM 5203, and AFSSM 7011, is required to reduce the effects of compromising emanations and meet TEMPEST criteria. Your project package should specify, in clear terms, precisely how to install all telecommunications equipment in a secure environment. The information in this chapter introduced you to some of the RED/BLACK equipment installation requirements, but certainly not all of them. Familiarize yourself with all special installation requirements before you begin work, the end result will be a professional installation which meets TEMPEST standards.



A properly installed grounding system is a critical factor in reducing compromising emanations. This is because faulty grounds can radiate signals which may be picked up by equipment and transmission lines thus negating all other TEMPEST installation precautions. A TEMPEST approved grounding system is not restricted to just a piece of equipment or even an entire system. It could include an entire work area or, in some cases, the entire building you are working in.

The same degree of criticality also applies to bonding. Bonding serves to eliminate differences in potential between metallic structures, such as wire ways and equipment items. Differences in potential between high level and low level devices could result in a transfer of compromising emanations. Proper equipment, wire way, and ground bonding eliminates differences in potential and greatly reduces radiation of compromising emanations.

This chapter outlines basic principles of grounding and bonding. It includes essential grounding information explained in TO 31-10-24 and also addresses RED/BLACK TEMPEST installation criteria for grounding and bonding.


When installing equipment in secure facilities, you will probably be required to install part of the grounding system. Having a basic knowledge of the purpose of grounding systems and how they are configured helps ensure proper installation and enables you to recognize and correct potential installation problems.


Ground is an agreed upon potential to which all signal voltages are referenced. Earth, often considered at zero potential, is almost always the reference point. In addition to serving as a reference point, grounds provide a low resistance path which shunts undesirable currents (lightning, power transients, emanations, etc.) to the reference point.


A typical facility ground system consists of the Earth Electrode Subsystem (EESS), a Fault Protection Subsystem (FESS), a signal reference subsystem, and the lightning protection subsystem. To meet TEMPEST requirements, facilities which house classified information processing equipment require a more elaborate and more expensive facility grounding system than other types of C-E facilities. Since grounding is such a crucial factor in preventing compromising emanations, you should be familiar with the basic elements of a facility ground system.


An equipotential ground plane is often installed in secure facilities to reduce the effects of compromising emanations. This ground plane is most effective when it extends under or above all RED and BLACK equipment. This includes distribution frames, patch panels, and RED/BLACK processing equipment. In some cases, physical facility construction may dictate installation of a vertical plane; however, a horizontal plane is more effective than a vertical plane in coupling unwanted signals to earth. An equipotential ground plane is considered earth for the signal reference subsystem regardless of elevation or location. The plane is banded (welded or brazed) to the main steel structure of the building and to the EESS at multiple points.


While a good portion of the facility ground system installation is accomplished by allied support. EI teams frequently run grounds for all subsystems and tie them into the EESS. Therefore, you must be familiar with RED/BLACK grounding runs and how to connect signal grounds, EESS grounds, and how to ground cable ladders, conduit, and duct.


All equipment racks, cabinets, and cases are grounded to the equipotential ground plane using #6 AWG stranded copper wires. Separate ground wires are normally run for each equipment end item of each equipment rack. Ground conductors must be continuous and not spliced at any point. Ground runs are bonded to the plane and bolted to grounding studs which are welded to each rack or cabinet. Equipment cases are grounded through the rack/cabinet ground or are equipped with individual grounding conductors. If a cabinet case ground is not provided, you must install a ground terminal as near the power entrance point as possible.


RED and BLACK signal grounds are established by direct connections to the equipotential ground plane which is bonded to the EESS. For unbalanced signaling, the signal ground is established by a direct connection from an isolated signal ground bus in the RED distribution frame to the equipotential ground plane and the earth electrode subsystem. A BLACK signal ground is used to provide a signal ground reference in the BLACK distribution frame.


Cable shields for both RED and BLACK signal lines are circurnferentially bonded to the equipotential ground plane. Cable shields surrounding individually shielded lower frequency signal lines are grounded at one end. For grounding of existing RED/BLACK equipment and systems installed before MILHDBK-419A, Vol. II, was written, refer to MIL-HDBK-419A, Section 2.4, for guidance.


Cable ducts are grounded at one end. The duct is then bonded to the equipotential ground plane at the shortest distance between the duct and the ground plane. This is done by bonding the cabinets to the plane since the duct is tied to the cabinets. Cable ducts carrying AC power will be grounded to the AC protective ground bus in the power panel.


Correct hookup of FPSS ground conductors to equipment housings, cabinets, racks, conduit, ducts, distribution boxes, junction boxes, and other hardware is essential for the protection of personnel and equipment, and suppression of compromising emanations. FPSS ground conductors are normally green. The neutral and FPSS ground conductors are bonded together at the first service disconnect or service transformer and further bonded to the EESS. This is the only intentional grounding of the neutral conductor that's permitted by MIL-STDS and National Electric Codes (NEC). If an end item of equipment does not have a ground terminal, you must install one on the equipment case near the power entrance point. In shielded facilities, the FPSS conductor does not penetrate the shield, rather, it's bonded to the shield on the inside and outside. Refer to your project package, TO 31-10-24, MIL-STD-188-124, and MIL-HDBK-232A, for FPSS ground conductor installation guidance. Now that we've discussed grounding, let's look at bonding.


Bonding is the electrical connection established between two metallic surfaces to provide a low impedance path between them. A good bond is mechanically strong, resists corrosion and stress, and exhibits the same mechanical and electrical properties as the material which is bonded together. Common bonding methods include welding, brazing, soldering, or by compression bolts, nuts, clamps, and straps. Proper bonding is required to ensure the integrity of grounding subsystems and thereby reduce the chances of compromising emanations.


Welding or brazing, though not done by El teams, is the preferred method of bonding. In some cases, soldering is also acceptable; however, never use solder bonds for the FPSS or the lightening protection subsystems. The method of bonding frequently employed by El teams is pressure connectors. Various types of pressure connectors are available, but they should only be used if called for in your project package. More information about bonding is found in TO 31-10-24, Grounding, Bonding, and Shielding.


The EESS is normally constructed using No. 1/0 AWG 7-strand copper wire, which is buried in the earth at a depth of at least 1.5 feet below the surface. The wire is bonded by welding or brazing to 10-foot copper-clad steel rods driven into the earth around the facility at intervals not to exceed 20 feet. Welding or brazing is also the preferred method of connecting all ground subsystems to the EESS.


The equipotential ground plane is bonded to all adjacent structural steel frames by No. 1/0 AWG stranded wire. It's also bonded to the EESS at multiple points around the facility perimeter. You should bond all equipment signal grounds to the equipotential ground plane with the shortest possible runs of No. 6 AWG stranded wire. All connections should be welded or brazed; however, pressure clamps may be used if called for in your project package. Remember, to provide adequate TEMPEST protection. All equipotential ground plane connections must meet MIL-STD-188-124 and MIL-HDBK-232A specifications.


If you are required to install power-line filters, connect a No. 1/0 AWG stranded copper wire between the filter case and facility entrance plate. They are normally installed in one or more central locations and contained in RFI cabinets.


Proper installation of signal reference subsystem, lightning protection subsystem, and fault protection subsystem is critical to ensure the containment of compromising emanations. It's unlikely you'll be installing the EESS; however, you may be required to install portions of the equipotential ground plane. Whatever the case, remember that their value can be severely compromised if ground leads are improperly connected to equipment or bonding is not sound. An improperly installed grounding system in a classified environment renders RED/BLACK installation criteria useless. Be sure to follow your project package and consult the references cited in this chapter for installing RED/BLACK grounds and bonding protective subsystems to the EESS. If you have any questions, contact the project engineer or the Base EMSEC Manager for assistance.



When you have finished your TEMPEST installation, it's time to power up the equipment and start your test and adjustments -- right? Wrong! EI teams are required to perform a pre-shakedown inspection to ensure the equipment is installed properly in the right locations. When dealing with EMSEC you need to go a little bit further in the inspection process. This is because you must ensure all measures have been taken to suppress compromising emanations before initial application of power. This chapter provides basic guidelines on how to conduct a pre-shakedown inspection for compliance with EMSEC installation criteria.

Prior to equipment shakedown tests, you should carefully evaluate the entire installation to ensure the integrity of mechanical supports, wire ways, conduit, shields, and hardware brazing. You must also inspect all power lines, signal lines, and grounds for proper connectivity. Lastly, you must ensure each piece of equipment is installed JAW standard installation practices and it complies with TEMPEST technical specifications. Follow the guidance in your project package, NCCSCR 700-17, and this chapter to double check your work.


The Base EMSEC Manager is also obligated to evaluate the installation and uses AFI 33-203 to perform a RED/BLACK EMSEC inspection. Since NCCSCR 700-17 does not cover RED/BLACK inspections in detail and the Base EMSEC Manager should be well versed in TEMPEST installation criteria, it makes good sense that you jointly look over the installation. If possible, request the assistance of the Base EMSEC Manager when you perform your pre-shakedown inspection. Together, you may be able to identify installation discrepancies or future problem areas that can be affected now.

Basically, the remainder of this chapter is a series of items you should look at during your pre-shakedown inspection. It isn't intended to cover 100% of every possible check; it provides general items to check and what to look for. It's a good idea to inspect one particular area at a time; i.e., equipment layout, conduit, ducts, etc. We'll start with the power distribution systems.


Before starting the pre-inspection, review the applicable project package task instructions and project drawings to refresh your memory. Using the 31-1-series TOs and project package, examine the power distribution that you installed. Pay special attention to RED/BLACK installation criteria in addition to standard installation requirements.

Now that you have finished inspecting the power distribution, let's take a look at signal line distribution.


When inspecting signal line distribution, keep an eye out for RED/BLACK discrepancies involving spacing, crossover. shielding, and termination. Use your drawings and task instructions in your project package, as well as the TEMPEST directives, to ensure correct signal line distribution.

Once you verify correct signal line distribution, closely inspect the equipment.


Use the task instructions and drawings from your project package to inspect the equipment for compliance with TEMPEST installation criteria. Double check to ensure correct equipment placement and adherence to RED/BLACK spacing requirements.

Remember to first identify the equipment type and the keying level. Refer to MIL-HDBK-232A, Tables I and II, as necessary to verify equipment spacing.

While inspecting the equipment, make necessary floor plan and other drawing corrections. We also recommend any RED processing non-developmental equipment be flagged on the drawings to indicate equipment is not TEMPEST approved.

Again review your project package for other RED/BLACK specifications which should be checked during your preshakedown inspection. Make other checks as necessary.


When you inspected the signal lines and equipment, you probably also checked part of the grounding system and observed some bonding. It's a good idea to make a final check of grounding hookups and make sure all hardware is correctly bonded. This is a difficult inspection as RED and BLACK ground potentials tied together are not necessarily visible. Make cursory checks; if you find an improper ground connection or incomplete bonds, dig deeper. If the Base EMSEC Manager is not with you on this inspection, it's wise to request his or her assistance to help identify conditions which could cause compromising emanations.


The purpose of a pre-shakedown inspection is to discover and correct discrepancies prior to equipment shakedown. A thorough inspection at this point is especially important to ensure compliance with RED/BLACK specifications. Take your time and use the collective expertise of the entire team. If you need help, get the Base EMSEC Manager involved. Remember, a good preshakedown inspection and correction of installation disparities aid in equipment shakedown and significantly reduce the potential of radiating compromising emanations.



Everyone who has been in the EI business for any length of time knows the overall responsibility for an installation rests on the Team Chief's shoulders. The Team Chief oversees it all, from the morale and welfare of the team members, to the quality of work, successful operation, and commissioning of the equipment or facility. In addition to the installation itself, the Team Chief also performs project reviews, pre-implementation surveys, continuous training, and a whole group of documentation. Most Team Chief skills are taught in the Team Chief Academy and learned on the job. This chapter does NOT rehash general Team Chief duties. It does, however, explain the extra considerations necessary to comply with TEMPEST criteria as the Team Chief begins a project review and pre-implementation survey. The most obvious place to start is the beginning: the project review.


As an EI Team Chief you've probably performed countless project reviews. Each project has its own individual problem areas which, when identified beforehand, can save a lot of frustration and manhours once the project is underway. Therefore, pay special attention to EMSEC requirements whenever you perform a project review. Following are some TEMPEST-related areas you need to closely scrutinize as you review the package.


The TEMPEST related parts of a project package are found in Tabs A and B.


Below are a series of references that may come in handy when reviewing a project package for EMSEC restrictions. The number, size, and type of TEMPEST installations performed by your team dictate which publications are required when you perform a project review.

While you may not be required to use every one of the above directives, it's a good idea to have them available. Your unit EMSEC Manager should have them on file. If not, then check with the Base EMSEC Manager. If not on file in your unit publications library, we recommend you establish requirements for the unclassified publications through your Customer Account Representative (CAR).

Now that you're aware of some references you may need to perform a project review, let's briefly discuss project review guidelines as they relate to TEMPEST installations.


You should follow standard project package review procedures for TEMPEST installations. As you perform the review, make note of all instructions, requirements, specifications, and restrictions related to TEMPEST criteria. Ensure compliance with TEMPEST requirements.

As you normally would, start off by inventorying all the parts of a project package to ensure it's complete. Starting with the cover sheet on TAB A, review each project package element from beginning to end for potential TEMPEST restrictions.


Review your findings and document them on AFCC Form 262, Record of El Project Review and, if necessary, AFCC Form 144, Narrative. You may or may not be able to contact the Project Engineer and discuss your findings. Obviously, you can't discuss classified information on the phone. Also, there are certain restrictions when reviewing TEMPEST-related packages, we'll cover these later. For now, let's assume there are no major discrepancies and the project can proceed without any engineering changes. Your next step is to take a team to the project location and perform a pre-implementation survey.


Once on site, you must verify allied support was completed IAW with the PSA and perform a thorough equipment inventory. Pay special attention to ensure full compliance with TEMPEST criteria.


Inspect the facility against the floor plans to verify equipment can be installed in identified locations. Check to verify equipment location complies with applicable TEMPEST directives and meets all RED/BLACK spacing requirements. If there are deviations to RED/BLACK equipment location and spacing standards, the customer must have a valid waiver.


TEMPEST-related allied support items you should closely inspect during the pre-installation survey include the grounding system, shielded enclosures (if required), and power distribution. In some cases, your team may be installing part or all of these subsystems. If some of the areas are unfamiliar to you, it may be beneficial to request assistance from the Base EMSEC Manager.

1 . Check records of the facility ground system to ensure is does not exceed 10 ohms.

2. Check the records of the Earth Electrode Subsystem (EESS) for compliance with the requirement of 10 ohm maximum resistance.

3. Visually inspect all power runs to ensure they are enclosed in nonferrous conduit and are properly identified. Verify correct distribution of technical power and there is no mixing of technical and non-technical power. Make sure power distribution boxes are properly located and separate boxes are used for RED and BLACK distribution. Check for bleeder resistors in the filter box (if installed).

4. Inspect and verify RED/BLACK areas are properly identified and isolated from each other IAW the project package.


During the pre-implementation survey, you should verify classified equipment and items required to perform operational tests have been received or are on order. Requisitioning such items as COMSEC equipment and ancillary devices, spare parts and circuit board kits, and classified and unclassified crypto keys is normally accomplished by the COMSEC custodian, crypto maintenance workcenter, or both.


While checking, the status of equipment, you can also coordinate maintenance support to be provided by the O&M unit crypto maintenance work center. Normally the O&M unit for which you are installing the equipment is obligated to support your team by obtaining "C" coded items and providing certified personnel to assist in the installation and perform operational checks and maintenance as needed. The results of their tests are normally used to verify operational capability leading to facility or equipment commissioning. If you have any problems, talk to the O&M unit Chief of Maintenance.


During the course of your pre-implementation survey you should be taking notes. Along with obvious discrepancies, you may have numerous questions on items you're not 100% sure of. Prior to documenting your findings, it may be a good idea to check out your findings with the Base EMSEC Manager. He or she may be able to clarify gray areas and verify whether or not a valid discrepancy exists. The best rule of thumb is, if in doubt document it on AFCC Form 250. Remember though, as mentioned previously, youjust can't pick up the phone and discuss classified discrepancies with your boss or the project engineer. You must always exercise full security measures when dealing with classified information. Let's look over some of the important security precautions you must always practice.


The whole purpose of this handbook is to identity and discuss the unclassified portions of TEMPEST installations. It would probably be impossible to install equipment in a TEMPEST facility and not become involved with some type of classified information or equipment. While conducting a project review, performing a pre-implementation survey, and during the installation, there will be times when you must discuss classified information with someone. As you already know, there are many restrictions with which you must comply to prevent security compromises. Let's take a look at some security precautions you must apply at all times.


Number one is the golden rule to not discuss classified information on the phone or write it down. Everyone knows that; however, a lot of times we may attempt to talk around classified subjects. Obviously, this is a no-no; don't be guilty of possibly exposing classified information in the name of just trying to do yourjob. Even though you may have the best intentions, it makes little difference in a compromise situation. Most units have at least one STU III terminal. You should have one in your unit, and the communications squadrons in the field should also have them. Discuss classified business over a STU III in the secure mode. Incorporate your questions or findings in a message to the engineer. Make sure the message is appropriately classified before release.

If you are not sure of or cannot locally resolve a problem, classify your work until you receive competent guidance to do otherwise.

The Base EMSEC Manager will assist you in this. It's best to be overly cautious when dealing with potential classified information than to risk a security compromise. If a project exception reveals a security weakness, the completion certificates will be classified. Guidance in this situation can be supplied by the Base EMSEC Manager. Any specific guidance and instructions received will be in writing and classified as necessary.


Just as important as not discussing classified information is making sure documented classified information is afforded the degree of protection dictated by its level of classification. There may be times during the project review, pre-implementation survey, or during or after the installation, when you must document classified information. Most classified documentation requirements are noting discrepancies, updating drawings, or communicating with the project engineer or program manager. Remember, when you must document classified information or deal with classified documents, protect them at all times.

1. If changes to a classified blueprint, photo, or drawing are required, they become attachments to AF Form 1146. While in your possession, take measures outlined in AFR 205-1, Information Security Program, to safeguard classified documents. The Base EMSEC Manager will help you classify documents and determine the proper method to disseminate classified correspondence.

2. AF Form 1261, Information Systems Acceptance, Commissioning and Removal Certificates, is used to document whether or not the installed equipment meets the TEMPEST criteria specified in the Project Support Agreement or Communications-Electronic Project. In the description portion of AF Form 1261, enter only the Standard Facilities and Equipment Listing (SFEL) designator if the equipment is classified. If the equipment is unclassified, the AF Form 1261 is processed normally. Now let's discuss actions to be taken if discrepancies are discovered.


Project discrepancies discovered during testing are usually corrected on-the-spot. If they cannot be corrected, they will be exceptions to the project. Rarely will you complete a project without some exceptions. Exceptions to C-E projects are grouped into two categories: minor and major.

1. Minor exceptions do not keep the C-E facility or system from meeting operational requirements, but keep it from meeting all installation criteria. A key point here is that the system, equipment, or facility must meet all TEMPEST installation criteria. If it doesn't then it becomes a major exception. Minor exceptions are cleared by the El Team or by the customer. Document on the AF Form 1261 the exception, forecast date of correction, responsible activity, and the date corrected, if applicable.

2. Major exceptions keep the C-E facility or system from meeting the specified operational requirements. This could be the result of not following proper RED/BLACK installation criteria or faulty equipment. The El team will correct all discrepancies if possible. If not, the facility may not be commissioned until the major discrepancy is cleared or a waiver is approved. In extremely rare cases, the customer will accept the project with a major exception. An Acceptance of TEMPEST Risk (AOR) is generated by the customer through the Base EMSEC Manager, and the AF Form 1261 is signed relieving EI of all responsibility for the project.


Performing project reviews for TEMPEST installations is a critical step in the installation process. Carefully examine the project package for any problem areas. The identification and correction of problems at the beginning saves time, manpower, and money when the installation is underway. While performing a preimplementation survey, ensure all support is available and that there are no deviations from the project package requirements. When dealing with material of a sensitive nature, be sure to take proper security precautions. It's tempting to try to talk about a TEMPEST problem over the phone with the project engineer; unless the phones are secure, don't try it. By adhering to proper installation methods IAW RED/BLACK installation criteria you can prevent the loss of compromising emanations and enable the Air Force to perform its mission in a secure environment.