Miniature covert body recorder
The CBR, or Covert Body Recorder, is a hi-end electronic body wearable
miniature audio recorder,
developed by Nagravision SA
(now: Nagra Audio)
in Cheseaux-sur-Lausanne (Switzerland). It was introduced in 2007 
as the successor to the tape-base Junior Body Recorder (JBR).
The device is intended for covert recordings and espionage and is mainly
used by intelligence agencies
and the law enforcement community.
Therefore, its specifications were kept secret by the manufacturer.
The bare CBR itself measures just 55 x 60 x 12 mm and is housed in a typical
Nagra eloxed aluminium enclosure. It it powered by two AAA-size batteries
that are contained in an external battery holder that is attached to the
bottom of the CBR by means of a slide-on lock. Both the device and the battery
are shown on the right.
The audio quality of the CBR is unsurpassed. The device can record nearly
3 hours of audio from two miniature microphones (stereo) in linear
Pulse-Coded Modulation (PCM)
with a sampling rate between 32 and 48 kHz (typically 44.1 kHz).
When using data compression, the built-in 2 GB memory can hold over 69
hours of sound, whilst the audio quality, remains excellent. Depending on the
type of batteries, the device can record continuously for 6 to 10 hours.
For unattended recording, the device can be voice actuated (VOX).
The CBR comes with a software package that runs on MicrosoftTM compatible PCs.
It allows all aspects of the CBR to be configured, such as the file format,
the amplifier levels, the sound compressor and the real time clock. If a
recorded conversation has to be submitted for evidence in a trial,
an SHA-1 signature can
be added to ensure that the file has not been tampered with.
Development of the CBR started around 2004, but the device wasn't released until
2007 . It was intended as a replacement for the
Junior Body Recorder (JBR), the last generation of
tape-based body wearable miniature covert recorders
that was developed in cooperation with the FBI.
The CBR was still available from Nagra in 2014,
but is not listed in the normal catalogue.
It is for the law enforcement and intelligence community only,
and costs approx. EUR 2040 (excl. VAT).
Apart from the CBR, Nagra also offers the CCR,
which is a covert recorder in credit card format.
The image below shows a complete covert recording setup with the Nagra CBR
at the heart. The unit is powered by a small battery pack (with two AAA-cells)
that is attached at the bottom. At the left is the
plastic remote start/stop slide-switch.
At the right are the two miniature microphones.
Like its predecessor, the Nagra JBR,
the CBR has virtually no controls, except for the
This was done to avoid operator errors
and tampering. All further settings of the CBR are under software control and
have to be adjusted by means of a PC prior to its assignment.
Recording can be started and stopped either with the
red slide-switch on the side of the recorder,
or with the separate remote control unit.
The exact function of each of these two switches can be
determined in software. It is also possible
to use one switch for playback.
At the rear is a small red LED that is used as an
When recording, it flashes quickly. The LED
can be concealed by a nifty mechanical cover,
so that it won't give itself away when used in the dark.
Initially the 90° 3.5 mm jack plugs and the remote control unit were
custom-made Nagra parts, milled out of a solid block of aluminium.
Later, the aluminium parts were replaced by
This might have been done to reduce the overall cost
of the unit, but could also be done because plastic is softer than metal and
therefore causes less damage to the operator's clothing.
The Nagra CBR is powered by two AAA-size batteries that should be
installed in the separate battery unit shown below. The battery
holder can be opened at the side by unlocking the bright blue
cover. The orientation of the batteries is printed on the cover
of the battery holder.
The image on the right shows the CB-BB1 battery holder with one of the sides
taken off and one AAA-size battery half-way inserted. The two batteries
should provide enough energy for continuous recording of up to 6 to 10 hours.
If longer recording times are necessary, for example when using the device
in unattended voice-operated mode (VOX), the separate
CB-EDC external DC adapter
can be installed in place of the battery holder. It has the
same form factor as the battery holder and allows any DC source between
8 and 16 Volt to be used.
The external DC adapter has a
socket for a 2-pin LEMO connector at its side
and should be used with the supplied
extension cable and virtually any external
DC source, such as the battery of a car.
Using this feature in combination with voice-operated recording (VOX)
and data compression, the Nagra CBR can record over 69 hours of sound
over a period of several days.
Like its predecessor the Nagra JBR, the Nagra CBR is a recording-only
device, which means that an external unit is needed to play back a
recorded conversation. Whilst this was done in the past with external
tape players, an ordinary PC can now be used to play back the CBR's
The CBR is connected to the PC via a common USB interface using the
supplied cable. Supplied with the kit is a mini-CD with the necessary
software that runs under Microsoft WindowsTM. This can be installed on
a native PC or on an alternative platform using PC emulation.
Once the software is installed, the PC can be used as a fully fledged
playback system, with full control over the various samples and the date
and time they were recorded. Samples can be transcribed and fragments
can be exported for use elsewhere, e.g. for further investigation.
The software is also used for setting up the device for the required
task. The function of the ON/OFF switch on the body of the
CBR and the function of the external remote control switch can both
be defined from the software. Furthermore, the software is used to
set date and time of the internal real-time clock, select between
Linear PCM and compressed audio, set the recording levels,
enable voice-operated recording,
select between internal and external microphones, etc.
CB-RC1Remote control unit
CB-EDCExternal DC Adapter
- Nagra Audio, Machine History
Retrieved July 2014. 1
- Nagravision SA, Nagra CBR Manual
Part number 2027 001 150. Version 4 january 2008. 26 pages.
The Nagra CBR used to be listed in the
Machine History overview
on Nagra's website until July 2014. In the current
Product History overview
it is no longer listed. The original list can be found here.
Any links shown in red are currently unavailable.
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© Crypto Museum. Created: Friday 25 July 2014. Last changed: Tuesday, 13 June 2017 - 18:01 CET.