TSCM - Common Bugging Frequencies

Major "Real-World" Bugging Frequencies

Over the years numerous TSCM and intelligence professionals have asked for an outline of the RF spectrum used by popular bugging devices. Bugging devices may utilize any frequency between DC and light; however, this list will cover the more common bugging frequencies that tend to be used by eavesdroppers.

The frequencies that follow are all based on hard documentation (catalogs, intelligence reports, technical materials, court documents, and specific device protocols). For the purpose of analysis the Source Reliability Scale should be considered A, and the Data Validity Scale should be rated as 1.

If the TSCM specialist already knows what frequency the RF eavesdropping device is (or may be) operating on, then the detection of the device becomes several orders of magnitude easier. For example a very popular "SpyShop" bug frequency is 398.605 MHz, 300.455 MHz, and 399.030 MHz. By configuring a modern spectrum analyser or receiver and targeting the specific parameters of this device it may be found from hundreds, and often thousands of feet away. There are roughly 3500 popular "bugging" frequencies used by the various Spy Shops devices around the world. It takes less then 5 minutes for a computer controlled radio to check all 3500 channels. Of course the entire RF spectrum still has to be checked in detail (which takes many hours), but knowing what specific frequencies might be used by the opposition gives the TSCM specialist a major advantage.

Remember to check the entire RF spectrum, not just specific frequencies; however, keep in mind that people doing bugging like to stay clustered around certain frequencies (it's one of their trade craft errors that can be exploited to bring about their demise).

Several PI schools, TSCM schools, and spy shops sell equipment (at highly inflated prices) and actively attempt to mislead students that all they have to do is spend a few hundred to a few thousand dollars on equipment to enter the TSCM field. Markup on these bogus products are typically greater than 400%, and what the spy school buys or builds for $100 they sell to their gullible customers for thousands or even tens of thousands of dollars.

For every legitimate TSCM firm there are 500 con artists (cloak and dagger types) who buy "CIA Bug Detectors" for $ 50 and resell them to their corporate clients for $ 8,500 (it's usually just a primitive broadband diode detector system). They remove the original markings and apply a stick-on labels with their name. Often they will even reprint the operators manual with their own logo and name. Some will even go so far as to have the client sign bogus security clearance or confidentiality documents to make the transaction appear even spookier. These spy-shops are trying to modify reality and the laws of physics to help them pad their bank accounts. Beware, Beware, Beware...

The frequency coverage of these special spy-shop bug detectors generally "top-out" at 1 GHz, with adapters and mixers the range they can sometimes be increased to 2-3 GHz. They are very limited value in finding bugs and tend to create a dangerous false sense of security.

Therefore, I say:
Know your enemy and know yourself;
in a hundred battles, you will never be defeated.

When you are ignorant of the enemy but know yourself,
your chances of winning or losing are equal.

If ignorant both of your enemy and of yourself,
you are sure to be defeated in every battle.

-- Sun Tzu, The Art of War, c. 500bc

Summary (this will identify the majority of the bugs and wiretaps sold in Spy Shops.)

All TSCM Inspections should include (at least) the following frequencies with an examination of both radiated and conducted signal pathways. Expect to see less than ten milliWatt maximum on the antenna, and for the signal to be present for only a small amount of time.

Audio Detection 300 Hz to 15 kHz Base Band Audio Ultrasonic 10 kHz to 150 kHz Ultrasonic Audio

VLF-Free Space 20 kHz to 350 kHz Video Cameras & Tape recorders

Carrier Current .3 kHz to 50 MHz 99% Voice (CC and PLA) Carrier Current 10 MHz to 450 MHz 99% Voice (AC Mains Antenna)

Free Space-HF 3 kHz to 50 MHz 99% Voice Free Space-VHF 30 MHz to 300 MHz 10% Video/80% Voice/10% Data Free Space-UHF 300 MHz to 900 MHz 25% Video/60% Voice/15% Data

Free Space-MW1 900 MHz to 3.0 GHz 50% Video/40% Voice/10% Data Free Space-MW2 3 GHz to 18.0 GHz Mostly Video and Data Free Space-MW3 18 GHz to 26.5 GHz Mostly Video and Data Free Space-MW4 26.5 GHz to 40.0 GHz (optional, based on threat)

...and of Course UV/Infrared! (Look for "Blooms")

150 - 450 nm Modulated UV Light Bugs 350 - 700 nm Modulated Visible Light Bugs (450 to 675nm very common) 700 - 1100 nm Audio Transmitters/Lasers (880 to 950nm very common) 800 - 1510 nm Audio Transmitters/Laser Microphones (rare)

750 - 900 nm Night Vision Illuminators 850 - 1750 nm IR Bugs and IR Illuminators

...and optical bugs installed INSIDE light bulbs and fixtures

450 nm - Modulated Tungsten bugs 490 nm - Modulated Sodium bugs 575 nm - Modulated Fluorescent bugs

An eavesdropping device may use the AC power circuits, telephone wiring, cable TV, or HVAC system wiring, as the transmission path (300 Hz to 450 MHz+), and may also use digital modulation or spread spectrum technology.

To find RF transmitters a search grid of less then 10 by 10 foot is used, and everything that causes any kind of deviation in the noise floor is investigated. Every cubic centimeter of the facility must also be carefully inspected with visual and electronic techniques.

For frequencies above 1 GHz a amplified dual ridged wave guide or standard gain horn (15-18 dBi) and low noise amplifier can be used to collect the signals (.5 GHz - 3 GHz, 1 GHz - 18 GHz, 18 - 26.5 GHz, 26.5 - 40 GHz, etc). The goal is to use highly directional horns, and then to amplify the signal to a high enough level to overcome all instrument noise and cable/connector losses.

Look for any electromagnetic energy on the RF spectrum, and not just specific modulation types. Once the source of the electromagnetic anomaly is identified then the modulation can be carefully analyzed to identify the signal type.

Remember: Bugs are always installed in groups of at least three: the one that was easy to find (the fools bug), the one that you will find if you really work hard (the novices bug), and then the real bug; that's almost impossible to find (the professional spies bug).

The following three charts represent the frequencies used by thousands of eavesdropping device identified during undercover operations, and/or seized in SpyShop raids around the United States. The population for this analysis was just over 2500 individual eavesdropping devices, and consisted of 43 different models. All models evaluated utilized power levels well below 50 mW, with most well below 15 mW. While the bugs were available on hundreds of frequencies the following 20 were the most common.

Composite Frequency Distribution Chart

VHF Frequency Distribution Chart

UHF Frequency Distribution Chart

In reality the only thing on earth that can actually find a bug is a pair of well trained human eyes, and a set of calloused and experienced hands. The electronic test equipment is only used to suggest to the TSCM specialist where to look, but does not in and of itself detect or find the bug or wiretap.

There are no magical black boxes that find bugs.

During a bug sweep or TSCM inspection all phone rooms, riser closets, demarcation points, and boots, must all be checked for tampering and electromagnetic anomalies (RF activity). All electrical outlets, light fixtures and switches, circuit breakers, distribution boxes, electric meters, and transformers must be checked for tampering and electromagnetic anomalies. The transformer and circuit breaker panel is the most important of these, as it's commonly modified to facilitate technical surveillance.

A microphone or video camera used for surveillance may be hundreds of feet away from the transmitter or recorder so be sure to check all potential transmission paths and not just the power and phone lines.

In a thorough TSCM inspection; RF Spectrum Analysis and monitoring should take place for at least twelve solid hours before a regular sweep. This part of the inspection is performed the day before the actual sweep, and will involve monitoring the ambient electromagnetic spectrum at locations AWAY from the actual facility (distances range from several hundred yards to several miles away from the facility). In cases when it is not possible to examine the RF spectrum in advance of the sweep at least six hours of time during the actual sweep should be spent examining RF signals.

When properly performed, a careful inspection of the RF spectrum can detect eavesdropping devices even from a considerable distance. Due to this it is highly beneficial for the TSCM team to examine the RF spectrum near the place to be inspected, but not actually inside the suspect area. For example, it is very desirable for the TSCM specialist to set up their instruments a few hundred feet away from the area to be inspected, and to spend at least six hours performing an instrumented analysis. In some cases this can be a conference room elsewhere in the building, a store room, warehouse, or even from a non-de script van located out in the parking lot. A side benefit to this type of an analysis is that it is not intrusive or disruptive at all.

To prepare for IPM or "In-Place Monitoring" the spectrum should be passively evaluated and monitored (inside the facility) for at least two or three hour prior to the meeting, general six hours is best (plus at least an hour or two for even the most basic of external physical examinations).

Many bugs targeted against corporate entities will generally have a transmit frequency between 20 MHz and 3 GHz. For someone willing to spend a little more money; bugging devices can be easily obtained which operate in the 3 GHz to 21 GHz range and above. This means the person performing a TSCM inspection must always inspect well above and below these frequencies.

A good rule of thumb is to check to at least five times the fundamental frequency of any credible RF threat. Up to the tenth or fifteenth multiple is ideal, and is actual dictated by various government standards. The radio frequency and signal analysis portion of any TSCM inspection should cover at least 9 kHz to 21 GHz (30 Hz to above 110 GHz is ideal).

VLF Emission and Subcarrier Detection

Common Eavesdropping Frequencies used by Amateur Eavesdroppers

Professional and Law Enforcement Bugging Frequencies

Surveillance Device "House" Frequencies/Bands

Federal Surveillance Frequencies

Surveillance and Spy Satellite Frequencies

Spread Spectrum and Frequency Hopping Bug Frequencies

Bandwidth Resolutions and Filters

Note: Typical TSCM inspections look for devices between 100 Hz to 450 MHz and conducted signals from 9 kHz to 40+ GHz.

Therefore, I say:
Know your oppositions capabilities and know your own equipment;
in a thousand bug sweeps, you will never miss a bug.
When you are ignorant of your oppositions capabilities but know your own equipment,
your chances of finding the bug are equal.
If ignorant both of oppositions capabilities and of your own equipment,
you are sure to never finding the bug, and the opponents spies will succeed.

- James M. Atkinson, c. 1986 ad (with apologies to Sun Tzu)

Extremely High Threat Frequency Bands

50 - 750 kHz - Carrier Current Bugs (power, phone, HVAC lines) 25 - 80 MHz Ultra low power devices (micro watt devices) 65 - 130 MHz Micro power Part 15 devices (FM broadcast band) 130 - 150 MHz Body Wires and Wireless Microphones - Band I 150 - 174 MHz Body Wires and Wireless Microphones - Band II 174 - 225 MHz Body Wires and Wireless Microphones - Band III

295 - 310 MHz Spread Spectrum and Micro powered Bugs (micro watt devices)

330 - 440 MHz Audio/Video Bugs (398.605, 300.455, and 399.030 MHz are popular) 430 - 550 MHz Audio/Video Bugs (433.920 and 418 MHz is popular) 800 - 990 MHz Audio/Video Bugs (902-985 MHz ISM band is popular)

1.10 - 1.95 GHz Video and Audio (980 MHz to 1.45 GHz is very popular) 2.00 - 2.75 GHz Video and Audio (2.4 to 2.45 GHz is extremely popular) 5.60 - 7.50 GHz Video and Audio (5.8 to 6.2 GHz is becoming very popular) 8.10 - 13.00 GHz Video and Audio (Popular)

850 - 950 nm Infrared Transmitters

Don't forget about the specific propagation and absorption bands. Bugging devices operating below 22 GHz are very inexpensive, and easy to buy. Devices operating between 22-60 GHz are more expensive, but just as easy to secure. Devices operating on frequencies above 60 GHz tend to be expensive, and can be very difficult to obtain.

    DC  - 3 kHz      Typical Audio Band 
  3 kHz - 500 kHz    Skin Effect (Non Radiating) 
500 kHz - 3 MHz      Non Radiating, Conducted RF 
  3 MHz - 300 MHz    Conducted RF, Free Space Radiating 
300 MHz - 3 GHz      Free Space Radiating RF, Slightly Directional
  3 GHz - 22 GHz     Free Space, Low Attenuation., Highly Directional
 22 GHz - 60 GHz     Water Vapor Absorption Band 
  60 GHz - 3 Thz     Limited Usage For Covert Surveillance

WARNING:
The area between 3 GHz and 40 GHz is a serious threat as the eavesdropping equipment in that range is inexpensive, readily available, very low power, and highly directional. Additionally, many TSCM people tend not to check frequencies above 1 GHz or 3 GHz (because the equipment is an order of magnitude too expensive for them to buy). Beware of any TSCM specialist who tries to convince you that there are no eavesdropping devices above 3 GHz (it is usually a dead give-away that they don't own any real counter-measure gear).

If you are concerned about covert eavesdropping or wiretapping then it would be wise to contact Granite Island Group, or another TSCM firm and schedule a "Bug Sweep" or TSCM Inspection. However, do not call from a suspect telephone, cellular telephone, or cordless phone and understand that it is critical that you should get someone out to your location as quietly, and as quickly as possible.

To be contacted for a confidential consultation
please E-mail: jmatk@tscm.com

or send a letter via US Mail to:
James M. Atkinson
Granite Island Group
127 Eastern Avenue #291
Gloucester, MA 01931-8008

or call:
Telephone: (978) 381-9111

URL: http://www.tscm.com/