Spectrum analyzer.

Spectrum Analyzers.

A good spectrum analyzer is the “workhorse” of the TSCM industry and, when combined with a computer, printer, and vector signal analyzer, will detect any RF eavesdropping devices (including those used by the FBI, NSA, CIA, MI5, etc.)

Hewlett Packard HP 71910A/P Wideband Receiver and Vector Signal Analyzer The HP 89410A is an ideal combination, but due to weight and cost parameters, it is used mainly by government, military and large corporation teams.

One of the attractive features of the HP 70000 series is that the programming language of the HP 8566 is virtually identical.

This allows the HP 70000 series to use programs written for the older HP 8566B.

The HP 71910 is also available as a single-rack system, which does not include a central processor. This allows the product to be controlled from an external notebook and allows the entire system to be transported in a compact case.

The frequency range covered is from 100 Hz to 26.5 GHz, with an extender to 40 GHz.

Using a pre-selection mixer, the range can be extended to more than 75 GHz.

Coverage from 75 GHz to 325 GHz can also be achieved, but only with the lower-performance HP 11970 base mixers, which lack sufficient pre-selection.

The HP 71910 is quickly gaining recognition in the TSCM industry and may become a mainstream solution for the next few years.

One of the biggest advantages of the HP 71910A/P system is its IF bandwidths from 10 Hz to 100 MHz (the 200 and 300 MHz bands require special modification).

These wide bandwidths are a big advantage when the threat is spread spectrum, frequency hopping, or digitally modulated eavesdropping devices.

The analog I/Q outputs provide a convenient interface to a dual-channel vector signal analyzer, such as the HP 89141A. However, an internal MMS card version of the HP 89141 vector signal analyzer will be available in late 1998.

The HP 71910A/P can be used as an excellent nonlinearity detector (NLO) and to control the internal microwave pulse or sweep generator. The color video output can be connected to a set of virtual goggles. The operator wears these goggles and moves the waveguide over the surfaces being examined while searching for nonlinearities.

A compact «case» version of the HP 71910 is expected in early 1999, and will include a UNIX controller, VSA, and flat-panel display in a 16 x 22 x 8-inch case. Unfortunately, Hewlett Packard is moving away from the MMS series in the near future and will instead be moving to more advanced VXI-based systems.

A Hewlett Packard HP 71910A/P spectrum analyzer configured for TSCM work will cost at least $97,000 (plus the cost of a vector signal analyzer).

GIG has developed several proprietary hardware & software products to enhance the HP 70000 Spectrum Analyzer and HP 89410A Vector Signal Analyzer as a tool for TSCM, TEMPEST and SIGINT.

The HP 8566B Spectrum Analyzer was the mainstay of TSCM for many years, but has recently been replaced as the primary system by the HP 71910 (see above).

The HP 8566B is a popular unit with military and government TSCM groups and every IATC trainee has a love/hate relationship with this unit.

This basic unit weighs just over 112 pounds and covers 100Hz to 22GHz without the use of external mixers. External mixers extend the range to 40GHz and often to 110GHz (the analyzer covers 325GHz).

There are hundreds of programs available to control this instrument for TSCM, signal analysis, TEMPEST testing, SIGINT work, and to facilitate TSCM functions including site monitoring.

Hewlett Packard discontinued these instruments in July 1997, but hundreds of these instruments are still in use and are excellent TSCM tools.

The cost of a TSCM configured HP 8566B Spectrum Analyzer ranges from $86,000 to $126,000 depending on the configuration. Used instruments can be purchased for between $15,000 and $48,000.

GIG has developed several proprietary software packages to enhance the functionality of the HP 8566B spectrum analyzer as a tool for TSCM, TEMPEST and SIGINT work.

The HP 8563 spectrum analyzer is also a popular choice due to its low cost, light weight, and frequency coverage. However, it lacks the sensitivity and inherent capabilities of larger units such as the HP 71919A/P and HP 8566B. The HP 856x series lacks the extended IF bandwidths used to detect modern eavesdropping devices.

The HP 8590 analyzers are very popular with TSCM teams. They are easy to operate, have wide band coverage, and have very narrow bandwidths. The low-cost E-series units are highly recommended; look especially for the HP 8594E with 9 kHz to 2.9 GHz frequency coverage (for under $15,000).

While the frequency coverage is certainly low, the 8594E's light weight and portable size make it invaluable for low-threat TSCM inspections.

An excellent spectrum analyzer for medium-threat targets is the HP 8564E, which provides frequency coverage from 9 kHz to 40 GHz (comparable to the 494A/P). Weighing only 44 pounds and priced at just over $55,000, it is small enough to be carried on most aircraft. Option 008 (Signal Identification) and Option 042 (Backpack) are highly recommended.

The Hewlett Packard ESA-L1500A 1.5GHz Spectrum Analyzer is a new, low-cost, fully synthesized spectrum analyzer with frequency coverage from 9kHz to 1.5GHz. It features a 21.4MHz IF output, fast warm-up, full PC control, and a VGA video output. The ESA-L1500A is designed to withstand harsh weather conditions and moderate abuse. It is well suited for TSCM (except for limited frequency coverage) and costs only $6,800.

Benchlink PC software allows you to create a communication channel between this unit and a laptop.

The Hewlett Packard E4900 Series Spectrum Monitoring System integrates a spectrum analyzer into a system that can detect RF transmissions. The system uses a laptop as a controller and connects directly to a plotter or printer at the output. In many ways, the most valuable feature of the system is the spectrogram display.

The E4900B (up to 1.8 GHz) is virtually useless for TSCM purposes due to its limited frequency coverage.

The E4901B (up to 2.9 GHz) is certainly popular, but for a portable unit that only covers up to 2.9 GHz, it is expensive.

E4902B-002 is a remarkable transportable system, the total cost of which does not exceed $ 100,000. This system is often used for in-house monitoring of corporate board rooms and law firms.

The Textronics 492 and 496 spectrum analyzers are older units that lack frequency stability (drift) and sensitivity. Many features, such as markers, are missing from this series. Typical frequency coverage is 20 kHz to 22 GHz. Used units can often be purchased for $1,500 to $6,500, but should be avoided for TSCM. The 492 and 496 spectrum analyzers cannot detect modern eavesdropping devices, which require wide IF bandwidths.

The Textronics 492 and 496 spectrum analyzers have become notorious in the TSCM industry for creating false alarms (due to chronic mixer problems). There is a joke among TSCM professionals that a group using a 492 spectrum analyzer can be detected from half a mile away, since the product “lights up” the entire local RF spectrum when turned on.

The Textronics 494A/P and 497A/P spectrum analyzers are a rarer addition to the 490 family. They have better frequency stability, markers, and better programming features.

The typical frequency range of the 494A/P is 10 kHz to 22 GHz, with an external mixer up to 40 GHz (or 325 GHz). The 497A/P operates like the 494, but its frequency coverage is limited to 100 Hz to 7.1 GHz.

The 490 series has been replaced by the FSE series, made in Germany. Used units can be purchased for about $25,000 (494A/P) and $15,000 (497A/P).

The 494A/P is the only spectrum analyzer in the Textronix 490 family that has found widespread use in the TSCM industry. An optional extra is available that enables the 494A/P to detect modern broadband eavesdropping devices in the IF bandwidth of up to 100 MHz.

The 494A/P is quite popular with U.S. government agencies performing TSCM work. It is fairly easy to operate and lightweight, but does not take a beating.

When used with an external modulator, the 494A/P is an excellent tool for a TSCM team that is constantly on the move and cannot carry lab equipment.

Tektronix 2782 and 2784 are high-performance high-frequency spectrum analyzers, excellent devices for TSCM work with the performance of a similar model HP 8566B.

The 2782 is an older unit with a frequency range of 100 Hz to 33 GHz. The 2784 is a newer version with a frequency range of 100 Hz to 40 GHz. The frequency range of either unit can be extended to over 325 GHz by using external mixers. Both units weigh up to 45 lbs. (without mixers) and are very sensitive to shock and vibration. Both units sell new for between $60,000 and $65,000, with prices ranging from $48,000 to $52,000 commonly used.

Both the 2782 and 2784 have a bandwidth of 3 Hz to 10 MHz. A special version is available that enables the Tektronix 2784 to detect modern eavesdropping devices with distributed IFs up to 300 MHz.

The use of an external demodulator makes the 2784 an excellent tool for TSCM teams that travel a lot and do not have the transportability of a laboratory-grade instrument.

Purchase of the 2874 controller software (S26UT00) and a complete set of hardware and software manuals is recommended.

Also recommended is the 18 (external mixers) kit to extend the frequency coverage of the 2784 to 110 GHz.

The Tektronix/Rhode & Schwarz FSE series of devices (with delivery 07) give TSCM specialists the ability to virtually determine any type of modulation and type of transmission or any type of technology known to people (all in one device).

In the frequency range limited from 20 Hz to 7 GHz, the speed and computer interface make the device very valuable. And the 7 GHz frequency limitation can be easily overcome by using external microwave mixers.

The FSEB30 can also be used as an excellent detector of nonlinearities in connections (unauthorized) by observing an external microwave signal or a sweep generator. The unit has a color VGA output that can be connected to virtual glasses. The FSE unit and the pulse generator can be placed in the center of the room. The operator then wears only these glasses while passing the waveguide over the surface to be inspected during the NLJD sweep.

The LCD display panel in the FSE unit has a tendency to perform poorly and is very sensitive to normal vibration during transportation. This series of units should be avoided until the team is able to operate in normal conditions (not on the move).

Analog spectrum analyzers.

It is also recommended that all TSCM teams have lightweight, battery-powered, low-frequency (up to 3 GHz) spectrum analyzers as a secondary spectrum analyzer. This makes it possible to have such a backup device as a spectrum analyzer for rapid deployment in the field (or for transportation by plane).

It is also nice to have a lightweight system that can be easily used on telephone poles, ceiling joists, air ducts, tight spaces, elevator shafts.

The Tektronix 2710 or AVCOM PSA-65C are excellent purchases and work well in this application. The older Tektronix 7L12 or 7L13 are also excellent analog units but are not recommended due to their weight.

Beware of any TSCM technician who uses only an analog spectrum analyzer (PSA-65C or 2710) or who uses older equipment such as the Tektronix 492 or HP-8550.

Additional Comments:

A) All spectrum and vector signal analyzers must be calibrated every six months, and a copy of the calibration certificate must be kept with the analyzer at all times. All mixers, preamplifiers, and preselectors must also be calibrated.

B) In the United States, microwave spectrum analyzers are considered military equipment (22-CFR Dual Use Positions) if:

1. The frequency range covers frequencies above 18 GHz. or
2. The greatest dispersion exceeds 2.3 GHz. or
3. The resolution bandwidth is greater than 3 GHz. or
4. Have a wideband input/output (>1 MHz)

All spectrum analyzers used in the TSCM industry fall under these parameters and are therefore a highly controlled item.

James M. Atkinson, Granite Island Group