KJB DNG2300-4, DNG2300-8, DNG2300 User Manual

USER MANUAL

DNG-2300

INTRODUCTION

ACOUSTIC EAVESDROPPING

Thank you very much for purchasing the DNG-2300 digital noise generator. The DNG-2300 is
designed to prevent listening though devices that cannot be detected by conventional
countermeasures and installed around the perimeter of a room – wired wall microphones, contact
microphones, AC outlet transmitters and window systems based on the reflection of
laser/infrared/microwave beams. It is an excellent addition to high level countermeasures.

It is well-known that sound distributes though walls, doors, windows and other constructions. In
some materials sound travels even better than through air. For example, water is a good conductor
and a heating system can pass a conversation out of a room. Eavesdroppers take advantage of this
with the use of contact microphones. These microphones pick up the vibrations from the air ducts,
plumbing, structures, walls, windows, doors, floors, ceilings and more. The microphones may not
be in the same room as the conversation, but may be several floors or rooms away attached to a
pipe or other fixture.

The DNG-2300 can render these devices useless. It produces non-filterable acoustic noise which is
transferred to constructions by transducers and speakers. REI’s TRN-2000 is the recommended
transducer for use with the DNG-2300. It has optimal power parameters and can be set on different
types of surfaces. The TRN-2000 injects most of its power into surfaces while only a tiny part of
the noise gets inside a room. This does not force people to speak louder. The TRN-2000 transducer
can be supplied with adapters for mounting on walls, ceilings, windows, etc.
The speaker OMS-2000 can also be used with the DNG-2300. It does not inject the noise into the
surfaces but radiates it into surrounding space. The OMS-2000 is usually used in air ducts, ceiling
tiles, etc.

TRULY RANDOM NOISE

The DNG-2300 consists of 3 independent white noise digital generators. “White” means that the
noise is fully random and is equally distributed along the voice spectrum. This distribution
provides complete resistance against the filtering of a conversation. Another feature of white noise
is its unpredictability i.e. there is no method to wipe it out from a recorded conversation.

VOICE MASKING

Men’s and women’s voices consist of lots of frequencies simul taneously produced during speech.
These frequencies lie between 100 Hz and 6000 Hz. Listening devices usually have a narrower
range mostly because of size limitations, the scheme of the device and battery time. The DNG­2300 has a range of 250-5000 Hz which is optimal to cover all types of voices and suppress all
listening devices.

OPERATION

The DNG-2300 uses a combination of transducers and speakers placed strategically throughout a
target area to create a blanket of masking noise that covers private conversations from
eavesdropping. Each transducer utilizes adapters for mounting to a variety of surfaces such as
walls, windows, ductworks, plumbing, etc. The three separate channels allow the user to tailor the
noise for separate materials, allowing greater flexibility and increased protection.

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LOOPBACK INPUT

The DNG-2300 has an input LOOPBACK which allows easy and fast tuning to the necessary level
of noise. Optional probe microphone DNG-MIC and probe stethoscope DNG-STET are used for
the required measurements.

SUPPLIED SET

The DNG-2300 is supplied with AC power cable and user manual. The TRN-2000 and the OMS­2000 are sold separately. Their quantity depends on the room size and the situation. The probe
microphone DNG-MIC and the probe stethoscope DNG-STET are also sold separately.

REMARKS REGARDING PREPARATION

This instruction manual covers the installation, wiring, and testing of the DNG-2300. Because the
DNG-2300 protects the perimeter of the target area, devices which may be planted in close
proximity to the target speaker’s voice may not be jammed by the DNG-2300 system. Therefore
prior to the installation of the DNG-2300 it is recommended to perform thorough sweep
accompanied by a physical search.

When performing detection and location the following tools can be used: radio field indicators (bug
detectors), interceptors, frequency counters, counter surveillance probes, spectrum analyzers, etc.
Contact your dealer for help in choosing the necessary tools or ordering a sweeping service.

While the most accessible listening devices can be detected by the mentioned equipment, there are a
lot of devices which can only be found by physical methods: wired microphones, fiber optic
microphones, passive resonators, inactive remote controlled “dormant” devices, or other non­detectable devices. Therefore a physical search is a very important part of countersurveillance work.

CONTROLS

FRONT PANEL

Figure 1

1. Power switch

2. Level indicator - Channel 1

3. Level indicator - Channel 2/ Level indicator - LOOPBACK input

4. Level indicator - Channel 3

5. Level adjustment - Channel 1

3

6. Level adjustment - Channel 2

7. Indicator switch on/off Channel 3

8. LOOPBACK input

9. Level adjustment - Channel 3
REAR PANEL

Figure 2

1. Output terminals – Channel 1 & 2

2. Input switch on/off Channel 3 (contacts open – channel on, the contacts are closed – channel

off)

3. Output terminals – Channel 3

4. AC power input (220V for European version)

TRANSDUCER INSTALLATION

Since the DNG-2300 uses the TRN-2000, which is produced for the ANG-2000/2200, it is
recommended to follow the instructions stated in the User Manual of the ANG-2000/2200. For your
convenience, they are repeated below.

INTRODUCTION

An ideal installation would be accomplished during construction or remodeling where sensitive
points in the structure can be protected with transducers built into the building's structure. If this is
not possible, the transducers can be placed directly onto wall surfaces. If visual appearance is a
problem, the transducers should be disguised or covered accordingly.

QUANTITY REQUIRED

Determine the quantity of transducers needed by these recommendations:

WALLS - One placed every eight linear feet, centered between floor and ceiling. Mount on or within
6 inches of a stud.

FLOOR and CEILING - One centered on every 64 square feet. (Use the OMS-2000 speaker for drop
ceiling.)

WINDOWS - One placed on every major pane of glass within 6" of the corner.

DOORS - One placed adjacent to the center hinge on the doorframe.

Note: "Shielded Screen Rooms" are shielded against R.F. devices transmitting out of the room,

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