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TSCM NLJD USSR KGB Stasi
The device consists of three functional blocks: a
power supply unit (PSU),
a transceiver (TRX)
and an antenna. Together with cables and other parts
it was usually supplied in an aluminium suitcase.
It has a pulse transmitter, much like radar, that creates 1.2µs pulses
on a frequency 2 near 875 MHz, with a repetition rate of 500 Hz or 20 kHz.
In contrast to most competitive NLJDs, it has a high power output, of
10-35 Watts, or even 350 Watts 3 .
The image on the right shows a typical Orchidea-3 set that was used
for many years by the secret security service of the
DDR,
the Stasi.
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The device works by the virtue of the fact that semi-conducting
materials — in particular the P-N junctions found in diodes, transistors
and ICs — have non-linear properties. When such an object is illuminated
by a particular frequency (f1), these properties cause
harmonic frequencies of the illumination frequency to be generated,
in particular the 2nd harmonic (f2) and the third one
(f3). This effect is present in any P-N junction, regardless of
whether the device is powered or not.
Note that other materials, such as rusty nails and oxidised pieces of metal,
may cause a false positive. The receiver inside Orchidea-3 is suitable
for detection of the second harmonic (f2) only, which is usually
the strongest. Modern NLJDs
are often capable of checking the ratio between the 2nd and the 3rd harmonic,
in order to discriminate an electronic circuit from, say, a rusty nail.
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ОРХИДЕЯ (Ochidea) is the Russian word for orchid.
It starts with the letter 'O' which is common for Russian countermeasures
equipment of the era.
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According to sources on the internet [3], the microwave module inside the
transmitter is suitable for 500 to 570 MHz, but this appears to be
incorrect. The transmitter of the device featured here, produces a
20 MHz wide signal with its centre at 870 MHz. This corresponds to
the manual, which states 875 MHz ± 5 MHz [A].
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350W output is only possible with a repetition rate of 500 Hz.
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Orchida-3 consists of three functional blocks:
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IP Power inverter PRP Transceiver → transmitter (P) and receiver (PR) K Antenna
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The diagram below shows how the 3 units are connected. At the centre is the
Transceiver (PRP) which consists of a powerful 875 MHz impulse
transmitter (P) 1 and a receiver (PR) 2 that listens to its harmonic
frequencies. It is powered by 220V AC supplied from the mains,
or by a 12V DC battery, via a 10 metre long extension cable from the
Power Inverter (IP) 3 at the left.
The actual transceiver (PRP) is connected to the
Antenna (K) 4 by means of
two high-quality coaxial cables.
At the right is the object under test, which can be a piece of furniture,
a plastered wall, a wooden construction or a special test device, known as
the imitator, that behaves like a typical electronic circuit. The
imitator consists of two metal rods connected at the centre
by a non-linear device (a special detector diode). It can be used for testing
the device and for training personnel.
With a properly functioning Orchidea-3, the imitator should be
'visible' from a distance of 10 metres.
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P = Peredatchik (Russian: Передатчик) which means transmitter.
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PR = Priyemnik (Russian: Приемник) which means receiver.
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IP = Invertirovaniye Pitania
(Russian: Инвертирование Питаниая)
which means inverting power supply.
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K = Konus (Russian: Конус) which means cone.
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The diagram below gives an overview of the controls and connections on the
body of the main unit: the transmitter-receiver (transceiver). At the left
(hidden from view) is a 4-pin male socket
for connection to the
external power supply unit (PSU),
which is usually placed elsewhere in the room.
At the right are two coaxial sockets
(marked K1 and K2) for connection to the antenna.
The device has two front panels: one for the receiver
and one for the transmitter,
with the latter usually positioned at the top (when carrying
the device by the shoulder strap).
The transmitter has a large 4-position
dial marked РЕЖИМ (MODE) for selection of the desired
mode of operation. A similar dial is present on the front
panel of the receiver. It controls an 11-position attenuator that ranges
from 0dB to -50dB. Note that the headphones socket (part of the receiver) is
located at the front panel of the transmitter. This was probably done for
convenience, as it is at the top.
The main unit is powered by the external power supply unit (PSU) shown in the
diagram above. It is shown here from the rear, so that most connections
are clearly visible. The PSU can be powered by the AC mains or by a 12V
battery, all of which are connected at the rear. A voltage selector 1 on the
sloped control panel is used to select the local mains voltage. Both the mains
voltage and the battery voltage can be checked with the meter, even before the
device is switched ON. The red alarm lamp lights up when the battery is
connected the wrong way around (reversed polarity).
The third major component of the Orchidea-3 installation, is the handheld
dome antenna that is connected to the
main unit by means of
two coaxial cables.
A pistol grip can be attached at the rear for easier operation when
searching a room for hidden devices. The green rear panel holds the sockets
for the coaxial cables, and also acts as a reflector for the two concentric
tapered wideband helical antennas that are hidden inside the glass fibre
dome (or cone) at the front.
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WARNING — Note that the recessed contacts of the voltage selector can
be touched with a finger. This is potentially lethal, as they carry the
live mains voltage.
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The transmitter has the following modes of operation:
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20K 20 kHz repetition rate, 10-35W pulse 0 Standby 500 min 500 Hz repetition rate, 10-35W pulse 500 max 500 Hz repetetion rate, 350W pulse
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Herbert Kunz · personal account
Security services are generally not very open about their work and their
methods. It will therefore not be a surprise that there are virtually no
surviving stories about how the Soviets searched their embassies,
residencies and apartments, an how — if any — bugs were detected and discovered.
Luckily, this situation was different in the former
DDR (East-Germany).
Following WWII,
the DDR was established as a communist state in 1949,
administered 1 by the Soviet Union
(Russia). After the fall of the
Berlin Wall in 1989,
the DDR was reunited with West-Germany (BRD) in 1990,
the East-Germans became West-German citizens, and the
Stasi-archives
fell into Western hands.
The use of Orchidea-3 and other Eastern countermeasures equipment, is
well-illustrated by the stories of former countermeasures technician
Herbert Kunz,
some of which were published in the magazine Der Detektiv
over the course of 2012 and 2013. Following a number of spy incidents
in foreign DDR representations 2 , Kunz had been employed from 1974 onwards
as a technician at Abteilung Schutz (protection department) of the
East-German Außenministerium (Foreign Office).
In 1975, the DDR was recognised by the United Nations as an official
nation state, after which embassies, residencies and homes were established
in more than 100 countries. Needless to say that it was of the utmost
importance to the DDR Goverment that these objects were free of
covert listening devices (bugs).
During his time at the DDR Foreign Office,
Kunz
found numerous bugs, mainly by means of visual inspection and with help of
simple tools like field-strength indicators.
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All that changed when the Orchidea-3 NLJD was introduced in the mid-1980s.
Many objects were searched again, and a wide variety of bugs were discovered
by Kunz, most of which were though to have been planted by Western
adversaries, like the British
MI6
and the United States CIA.
The image on the right shows two of the items that were found in 1987 in London,
in the 12 cm hollow space between the DDR Embassy and its next door neighbour.
At the time it was believed that the items were planted by the British
secret intelligence service MI6
via the adjacent building.
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The large item at the top is an
SRN-58 antenna
for 1500 MHz, developed in 1969 by
the Dutch Radar Laboratory (NRP),
exclusively for the
US Central Intelligence Agency (CIA).
The smaller item is an SWM-44 microphone
developed in 1986 by the US microphone manufacturer
Knowles, also
exclusively for the CIA.
It seems therefore more likely that the bugs had been planted by the
CIA.
After the fall of the Berlin Wall
in 1989 and the subsequent reunification
of the two Germanies in 1990, Kunz stayed in the bug-finding trade
and made a living as a security advisor/engineer and teacher.
He used the Orchidea-3 for many years after the end of the
Cold War,
as it was able to discover bugs far more easily than its Western
counterparts, such as the Scanlock Broom
and the REI Eagle, not least
because of the much higher RF power level 3 of the illumination signal [2].
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Western bugs found in DDR objects
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Below is a non-exhaustive overview of the bugs that were discovered by
Herbert Kunz
and his colleagues, with help of the Orchidea-3
non-linear junction detector (NLJD) featured here:
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1986 Five remote controlled bugs in the DDR residency in Harare (Zimbabwe) 1987 Several Bugs in the new DDR embassy in London 4 1987 Operational bug in a DDR embassy personnel apartment in Cairo (Egypt) 1987 Defective bug in another apartment in Cairo (Egypt) 1987 Various bugs in the DDR representation in Bonn (West Germany)
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Except for West-Berlin, which was controlled by West Germany (BRD).
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For example: in 1973, telephone bugs had been found in the DDR representation
in London (UK), as well as manipulated mains wall sockets in Düsseldorf
(West-Germany).
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The Orchidea produces a 30 W (optionally 350 W) pulsed signal, whereas the
Scanlock Broom produces a 60 - 600 mW continuous signal.
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At the time, these bugs were attributed to the British
MI6, but in retrospect —
based on items in the collection of Crypto Museum — it seems
more likely that the bugs were placed by the American
CIA.
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The large green aluminium suitcase shown in the image on the right, was supplied
for storage and transport of the Orchidea-3 set. It has a custom-made
foam-padded felt interior, with cut-outs for the three major parts and their
accessories.
Although the suitcase provides proper protection of its contents, it can
be recognised from a mile away. When an observation team spotted this case
being carried into an embassy, they knew that the rooms were going to be
swept for bugs.
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Transceiver (main unit)
PRP
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The devices comes with a special antenna that consists of two spiral
cone antennas on a single axis: one for the transmitter at the illumination
frequency (f1) and one for the receiver at the double frequency
(f2). The two antennas are protected against damage by a
glass fibre cone. The green metal rear panel acts as a reflector.
The antennas have circular polarisation and an 80 degree opening angle.
The rear panel holds two coaxial sockets, K1 and K2, for connection to
transmitter and receiver. A pistol grip can be fitted to allow it
to be pointed in any direction.
➤ Look inside the antenna
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The main unit is powered by a 220V/400 Hz voltage, provided by the
external power supply unit (PSU) shown in the image on the right.
In Russian, the PSU is known as Инвертирование Питаниая
(Invertirovaniye Pitania, or IP), which means inverting power supply.
At the rear are the connections for the AC mains and for an
external 12V battery.
The socket for connection to the main unit is at the front.
The sloped top panel holds the ON/OFF switch, the mains voltage selector,
and a voltage meter.
➤ Look inside the PSU
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The pistol grip shown in the image on the right, can be
fitted to the rear
of the antenna (K), allowing it
to be pointed
more easily in the direction of the object under test.
The grip has a bajonet fitting at the front that mates with
the stub at the centre of the rear panel of the antenna.
It has a threaded ring at the bottom,
allowing it to be fitted on a tripod.
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A tripod was supplied for putting the antenna in a fixed position,
for example when examining multiple objects, by placing them one-by-one
in front of the antenna.
The pistol grip has a treaded hole at the bottom, which fits a regular
photographic tripod, such as the one shown in the image on the right.
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Two high-quality coaxial cables are supplied for connecting the antenna (K)
to the main unit (PRP). One cable connects the K1 socket of the transmitter
to the K1 socket of the antenna, whilst the other one connects the K2 socket
of the receiver to the K2 socket of the antenna.
The cables are approx. 2 metres long each, but longer cables can be used
if necessary, as long as they both have the same length.
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The external power supply unit (PSU or IP) is the only device that
should be connected directly to the AC mains, for which the cable shown in the
image on the right should be used.
One end of this cable has a typical 4-pin female plug – connected
to the 4-pin male socket at the rear of the PSU – whilst the other end holds a
power plug that fits a local mains wall socket.
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When searching a room for bugs, the main unit was usually carried on the
shoulder, using the leather strap,
whilst the power supply unit (PSU) was placed
at a fixed position, usually near a mains wall socket.
The PSU is connected to the main unit, by means of the 10 metre shielded
power cable shown in the image on the right.
The cable has a 4-pin male plug at one end, and a 4-pin female plug
at the other. Note that this cable carries a 220V/400 Hz voltage, which is
potentially lethal. The brown bakelite reel is an aftermarket addition.
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When using Orchidea-3 in an environment where no mains voltage is available, or
in situations were bugs are expected on the mains power lines, it is possible
to run the device from a 12V DC source, such as the battery of a car.
In that case, the large clips of the cable shown in the image on the right
(or a variant),
should be fitted to the (+) and (-) poles of the battery,
whilst the other end of the cable is fitted to the banana sockets at the rear
of the PSU.
The slide switch on the PSU should be
set to АККУМ.
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In order to get acquainted to the Orchidea-3, and for checking its
operation, the imitator shown in the image on the right is supplied. It
consists of a two metal pins – acting as antennas – with a radar diode at
the centre. As the diode consists of a P-N barrier, it has non-linear
properties that can be detected by the device.
With Orchidea-3 set to its highest power output of 350 Watts at 500 Hz
— MODE selector at 500 max — it should be possible to discover the imitator
from a distance of 10 metres [A].
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Each Orchidea-3 set comes with a cylindrical black plastic container that
contains spare parts, like fuses, radar diodes (used in the
imitator), screws, pins for the mains
power plug, etc.
In Russian, this container is known as
Запасные части И Принадлежности
or ЗИП (Latin: ZIP), which means: Spare Parts and Accessories.
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Initially, Orchidea-3 was supplied with a stethoscope-style earpiece,
but this was later replaced by the Russian military-grade pair of headphones
shown in the image on the right.
The headphones should be connected to the two-pin socket on top of the
device (i.e. on the front panel of the transmitter). It is used for reproducing
the audio tone generated by the echo (i.e. the f2 harmonic frequency)
of the pulsed f1 illumination signal.
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Instead of using the headphones shown above, it was also possible to use the
bare speaker shown in the image on the right. This is basically one half of
a pair of headphones, connected to a short cable with a 2-pin plug at the end.
This speaker is particularly useful for exercises and demonstrations, as the
echo tone can be heard by multiple people. It is not recommended for finding
bugs in a real-life situation, as the sound from the speaker can also be
heared by a potential eavesdropper, providing an indication that the room is
being swept for bugs.
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The leather carrying strap shown in the image on the right, can be
attached to the stubs
at the side of the main unit,
allowing the main unit to be carried on the shoulder, with the transmitter's
front panel facing upwards, and the front panel of the receiver at the bottom.
It allows the main unit to be carried through the room under test,
with the main unit connected to the power supply unit
via a 10 metre cable.
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Each Orchidea-3 came with an original technical manual in Russian –
with operating instruction and a full technical description –
complete with the circuit diagrams. In the DDR (East-Germany) the manual
was translated into German. 1
Bad quality copies of the German manual and the original
Russian circuit diagrams 2 are available for download below.
Crypto Museum
are still looking for an original Orchidea-3 manual.
➤ Download the German manual
➤ Download the Russian circuit diagrams
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The translation is not of the highest standard and contains quite
a few mistakes and translation errors.
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Better quality circuit diagrams – made by ourselves –
are available below.
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The device is housed in a strong machined aluminium enclosure, of which
the inside is silver-plated. It is soldered at the corners and the seams,
for proper RF shielding. The case has two compartments: one for the transmitter
and one for the receiver, that are completely separated.
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The transmitter and receiver are each built on a strong machined aluminium
plate that also acts as the front panel. The transmitter is installed in the
upper compartment, whilst the smaller but more complex receiver
is located at the bottom.
The modules are held in place by no less than 12 screws each, with
a metal gasket fitted between the panel and the outer case, in order to provide
sufficient RF shielding. Two of the screws are recessed and are secured
with a green wax seal
to prove that the case has never been opened for
repair, and that it hasn't been tampered with.
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The image above shows the transmitter section removed from the enclosure
of the main unit. Although the transmitter is the simplest circuit,
it occupies the most space, mainly because of the
large valve-based microwave module
and the fact that it holds the
internal power supply unit.
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The complete transmitter is visible at the top of this section.
At its heart is the large green 1ГИ01 valve-based (tube) pulse transmitter
shown in the image on the right. At the left are the wire terminals for the
filament and cathode, whilst the HT voltage is fed to the anode
at the right.
The 1ГИ01 is a complete RF microwave module that has a direct antenna
output – here visible at the bottom – that is connected to the antenna socket
via a long coaxial filter, here visible at the bottom right.
This coaxial filter suppresses the unwanted second harmonic
by at least 100dB.
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The microwave module is anode-modulated with short 1.2µs pulses, delivered
by a toriod pulse transformer,
which is driven by a transistor-based
pulse generator
with a repetition frequency of 500 Hz or 20 kHz.
Depending on the anode voltage and the duration of the pulse
— selected with the MODE dial —
the transmitter can deliver a peak-power level of either 10-35
or 350 Watts.
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The receiver is about 1/3rd of the size of the transmitter, but is
far more complex. It is fully transistor-based and consists of seven
sub-circuits, most of which are housed in individual metal enclosures,
connected via high-quality coaxial wires. It is powered by +20V from
the transmitter.
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The receiver is located at the bottom of the case (i.e. opposite the
transmitter) with its base plate acting as the front panel. Like the transmitter,
the receiver is held in place by 12 screws, two of which are
secured by means of a green wax seal.
The image on the right shows the receiver panel extracted from the main unit,
with a white teflon coaxial cable connected to the
coaxial band filter which
is permanently fitted inside the enclosure. This filter is adjusted for the
double frequency (f2) and suppresses the illumination frequency
from the transmitter (f1) by no less than 120dB.
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The remaining sub-circuit are all mounted to the base plate, as shown
at the top of this section. At the right is a PCB with a
small power circuit,
that converts the +20V from the transmitter into suitable voltages for the
individual modules. The flat device (here marked '00') is the
RF mixer.
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It combines the input signal from the antenna (f2) with the
signal from a local oscillator that is adjusted 100 MHz above the reception
frequency (f2) to deliver an 100 MHz IF signal. The image on the
right shows the free-running oscillator, which is built around two
1T387A RF transistors with their tuned circuits in stripline technology.
The output from the mixer is first amplified in a 2-stage IF pre-amplifier,
before it is fed to a 11-step attenuator that is fitted at the far
end of the base plate. It consists of a resistor network that is soldered
to the pins of a large rotary switch.
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The attenuator is the only part of the receiver that is not shielded
individually. Next, the signal at the output of the attenuator is boosted
in a 4-stage power amplifier which also holds the diode detector.
It reduces the bandwidth of the IF signal by means of tuned circuits between the stages.
The video signal at the output of the booster is then passed
to the last receiver module, which consists of a video amplifier, a pulse
shaper and an audio amplifier that drives the headphones.
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The antenna consists of a metal back panel that
acts as a reflector. It holds two coaxial sockets – one for the transmitter and
one for the receiver – and a fitting for the pistol grip.
At the other side
is a glass fibre dome that protects the internal antennas.
It is held in place by 6 recessed screws.
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After removing the screws, the protective dome
can be removed and the
antennas are exposed,
as shown in the image on the right. Inside the dome
are two tapered helical (helix) antennas, spirally-wound onto a hard
polystyrene foam body. Both antennas are used in axial mode, which means
that their sensitive direction is perpendicular to the reflecting metal
back panel.
The outer antenna is used for the transmitter. It is the longest of the two,
and is adjusted for the f1 illumination frequency. At the centre
of the transmission antenna is the reception antenna.
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It is shorter – about half the length of the transmission antenna – as
it is adjusted to the double frequency f2; the second harmonic
of the illumination frequency. The image above clearly shows the two
concentric polystyrene constructions, with the transmission antenna visible
as a silver-plated copper wire, guided around the circumference of the outer
cone, from the connector to the open end at the top.
Towards the top of the transmission
antenna, is a 150Ω series resistor.
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Due to its weight, the power supply unit (PSU) is housed in a separate
enclosure with two heavy black heatsinks at the sides and a sloped control panel on top. The latter is part of the U-shaped top cover
(painted in hamerite green) that is held in place
by 14 recessed screws; 7 at either side.
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After removing the 14 recessed screws, the top panel can be lifted off
— as shown in the image above — and the interior is
exposed. Inside the PSU is a
large toroidal mains transformer
that converts the 110 or 220V AC mains into 12V AC, which is then
rectified in a diode bridge and stabilised by two
4000µF electrolytic capacitors.
The resulting 12V DC drives a power inverter that produces 220V
AC at a frequency of 400 Hz, delivered by a
small toroidal transformer.
Instead of the mains, the inverter can also be powered by an external
12V DC battery source.
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The image above shows the printed circuit board (PCB) inside the PSU.
It holds a toroid-based 400 Hz oscillator, plus a booster which produces
enough energy to power the main unit (i.e. the transmitter and
the receiver). The reason for using 400 Hz
(rather than 50 or 60 Hz) is that it allows the use of
smaller power transformers,
which reduces the overall weight of the main unit.
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Below is the circuit diagram of the pulse transmitter. Although this circuit
occupies approximately 2/3rd of the main unit, it is the simplest circuit.
At the top left is the transformer, which converts the 220V 400 Hz voltage
– supplied by the external power inverter –
into the LT voltages (6.3V AC and 20V DC)
plus the HT voltage that is supplied to the anode
of the 1ГИ01/01-1 valve-based 875 MHz (adjustable) microwave module,
located at the bottom right. It is heated by 6.3V AC.
The +20V DC rail is used to power the receiver (see below). It also
drives a transistor-based oscillator, which in turn drives the pulse transforer
(TR3) in the anode circuit of the microwave module. The output is available
directly from the microwave module, and should be connected to antenna K1.
The 8-pin plug at the top left, mates with an
8-pin socket inside the enclosure.
Note that the speaker socket – visible at the top right –
is located 1 on the chassis of the transmitter.
Also note that the output of the 1ГИ01 microwave module is passed through
a coaxial filter
before it becomes available at the output socket
on the side of the main unit. This rigid filter is connected
directly to the output
of the 1ГИ01 and is not shown in the circuit diagram above.
It suppresses the harmonic frequencies produced by the transmitter with no
less than 100dB.
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It is likely that the speaker socket was placed at the front panel of
the transmitter for convenience only, as it is at the top side of the
main unit, when the latter is carried by the shoulder strap.
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The receiver is the smallest, but also the most complex part of the device.
It occupies about 1/3rd of the main unit, and consists of 7 sub-circuits,
which are shown in the block diagram below. The active units are powered from
the +20V DC rail, which is provided by the transmitter. The receiver is
configured for the reception of the harmonic frequency f2 —
which is twice the f1 frequency of the transmitter — that will
be caused by the non-linear properties of a hidden bug.
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Orchidea-3 receiver - block diagram
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Each sub-circuit is housed in an individual metal enclosure, with the exception
of the 11-step attenuator and the parts of the power supply, visible at the
bottom right of the diagram above. The signal from the antenna is first filtered
in a coaxial filter which is fitted inside the enclosure.
This filter supresses the strong direct f1 signal from the transmitter
with no less than 120dB.
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Mixer, consisting of directional coupler and signal diode
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From the filter, the signal is fed to the mixer shown above, where it is
combined with the signal from the local oscillator – shown below – that
oscillates at a frequency which is 100 MHz higher than the expected
f2 frequency. The mixer consists of
a directional coupler and a signal diode. It produces a 100 MHz signal
at its output port, which is fed to the IF pre-amplifier (see below).
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Local oscillator at f2 + 100 MHz
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The local oscillator is built around two 1T387A transistors in grounded
collector configuration, with the tuned circuit (L3 and C 1p5)
connected between the bases of the two transistors.
The circuit oscillates by the virtue of the
parasitic capacity between the base and the emitter of each transistor.
The output of the oscillator is taken from a tap of stripline L3 in the tuned
circuit.
The output from the mixer is first amplified in the circuit above,
which is a two-stage amplifier built around two low-noise 1T329A transistors.
The first transistor is used in grounded emitter configuration, whilst the
second one has a grounded base.
The amplifier is tuned to 50 MHz (via L3/L4),
which is the center frequency of the 100 MHz wide signal from the mixer.
The component values are selected such that the total bandwidth of the
signal at the output port is reduced.
The output from the IF pre-amplifier is
passed to the 11-step attenuator shown above. Unlike the other
sub-circuits, the attenuator is not housed in a separate metal enclosure,
but consists of a resistor network that is soldered directly to a 11-position
rotary switch on the chassis of the receiver. It can be controlled by the user
with a 11-position dial on the receiver's front panel.
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4-Stage IF power amplifier and detector
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The signal from the output of the attenuator is fed to the input of the
4-stage power amplifier shown in the circuit diagram above. This circuit is
very similar to that of the IF pre-amplifier, but is built around
2T316B transistors (Russian: 2Т316Б). At the right
is the 2A201A detector diode.
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Video amplifier, pulse shaper and audio amplifier
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The signal from the detector is fed to the input of the final sub-circuit,
which is shown in the image above. It consists a three-stage video
amplifier (T1, T2, T3), a pulse shaper (D1, D2), an AF amplifer (T4)
and finally an emitter follower (T5) that directly drives the headphones.
Note that the speaker is AC-coupled by means of a capacitor that is fitted
outside the circuit's enclosure.
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The diagram below shows the internal wiring of the main unit. The device has
two compartments: a large one and a small one, for the transmitter and receiver
respectively. It also has a shielded socket for the connection to the PSU. The
transmitter has an 8-pin socket
that mates with the 8-pin plug shown below.
The receiver has a 4-pin socket
that mates with the 4-pin plug below.
Large filters are present to block any RF energy from the power lines and
from the lines between the two compartments. An extra capacitor is present
on the +20V line. Note that the receiver is powered by the transmitter (+20V)
and that for no apparent reason, the audio from the receiver is fed back to the
transmitter compartment, where it is connected to the filtered speaker socket.
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Below is the circuit diagram of the external power supply. At the top left are
the inputs from the 110 or 220V AC mains (50 or 60 Hz) and the 12V DC battery.
A voltage selector (S2) is used for matching the local mains AC voltage, which
is converted to 12V by transformer TR1 and a diode bridge rectifier (D1). The
12V DC voltage from the battery is connected in parallel to the output of D1,
protected against reverse polarity by diode D3. A voltage meter is present at
the top right, to check the input voltage (mains or battery) prior to switching
the device on with power switch S1.
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External power supply unit
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The lower half of the diagram shows the actual power inverter,
which comprises an oscillator — built around transformer TR2 — and a booster
stage built around TR3. At the output of TR3, a fixed 220V voltage
with an alternating frequency of 400 Hz is present. This voltage should be
supplied directly to the main unit. The reason for using 400 Hz (rather than
50 or 60 Hz) is that it allows the output transformer (TR3) and the input
transformer of the main unit to be smaller.
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When we received our Orchidea-3 in October 2018,
it was in well-preserved condition, but it
was evident that it had seen quite some action over the years. It had been
travelling all over the world during the
Cold War – for finding bugs in
DDR
objects – and was used for many years thereafter.
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The front panels of the transmitter and receiver of the main unit had
several dents and scratches — all caused by regular use — and the power
supply unit had lost much of its green hamerite paint, as can be seen in
the image on the right.
None of the damages were serious and could be fixed easily. The cover of
the PSU and the front panels of the main unit were straightened, and the
paint was restored where necessary. Several connectors were refitted to
their cables as they had come off over time. The capacitors were all
checked and were found to be in good condition.
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Now it was time to bring it back to life again. The MODE selector was
set to 500 min, which means an output power level of 30W and a repetition
rate of 500 Hz. The PSU and the antennas were connected to the main unit,
and the mains voltage was applied to the PSU. After setting the power switch
to ON, the internal 400 Hz power inverter could be heard. After approx. 20
seconds — the valve needs to heat up first — an RF signal with the following
wide spectrum was emitted:
Due to the pulsed nature of the RF signal, many sidebands are generated,
resulting in a 20 MHz wide signal, with the centre frequency at
870 MHz. This corresponds to the frequency specified in the manual (875
MHz ± 5 MHz). The vertical lines in the spectrum diagram represent the 500 Hz
repetition rate. As both the 875 MHz module and the 500 Hz pulse generator
are free-running, the vertical lines will be moving through the
spectrum continuously (i.e. there is no correlation).
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The first test were carried out with the imitator on the floor of our
workshop. It was detected immediately and it became evident that the
antenna has quite a wide viewing angle (approx. 80 degrees). The imitator
could be 'seen' from several metres away without any difficulties.
Next, we tried the device with several regular components like diodes
and transistors, with varying success. Simple small signal diodes were
easily spotted, but a transistor was more difficult to find, especially
when its legs were in parallel. Bending the legs outwards gave better
results.
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There were also some false positives, probably caused by
(rusty) iron structures in the concrete floor of our workshop. It is
clear that operating an NLJD properly requires quite a bit of practice,
but by adjusting the power ouput of the transmitter and the attenuator
of the receiver, it should be possible to find electronic
circuits. Not bad for a device that is more than 30 years old now.
Actually, there were only two real problems with the set: (1) the meter
on the power supply unit was dead and (2) the foam inside the suitcase
had completely disintegrated and had become a sticky mess.
- to be continued...
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So far, the following restorations have been carried out:
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- All parts cleaned
- Paint on the body of the PSU restored
- Paint on the front panels of the main unit restored
- Mains cable 4-pin connectors refitted
- Power cable (reel) restored and connector refitted
- PSU tested
- Main unit tested and approved
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Although the main unit has the same 4-pin power socket as the external PSU,
it should always be powered via the PSU and not directly from the mains.
The reason for this is that the main unit expects a 220V AC voltage with
a frequency of 400 Hz, whilst the mains is at 50 or 60 Hz. The diagram
below gives the pinout of the power socket on the PSU, when looking into
the socket.
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- 220V AC
- not connected
- not connected
- 220V AC
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The same connector (male and female) is used for connection between the
PSU and the main unit. Note that this cable carries 220V at 400 Hz
(not 50 or 60 Hz), which is not compatible with the regular 220V AC
mains voltage. The pinout of these connectors is as follows:
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- 220V AC
- not connected
- Ground
- 220V AC
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1GI01 (Russian: 1ГИ01) is a coaxial waveguide microwave module,
based on a thermionic valve (vacuum tube),
designed as a self-oscillating generator with anode modulation.
It is heated with a 6.3V filament and can produce pulses of up to 3 kW.
The RF output is available at a coaxial screw terminal at the side of
the device [3].
➤ Datasheet
Specifications
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Frequency 875 MHz ± 5 MHz 1 Heater 6.3V (6 — 6.6V) Anode pulse 3.5V (≤ 3.7V) Gride pulse -250V — 0V Anode current 2.3A (≤ 2.6A) Cathode current ≤ 5A Output pulse ≤ 3 kW Duty cycle ≥ 1: 600 Duration 0.5 — 1.2 µs VSWR ≤ 1.7 Drift ± 0.3 MHz Shelf life ≤ 12 years MTBF 1000 hrs Temperature ≤ +140°C Weight 270 grams
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Some websites [3] specify the frequency range as 500 - 570 MHz,
but this is likely incorrect.
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Temperature Storage: +5°C — 30°C, transport: -50°C — +60°C Humidity ≤ 85% Weight 13 kg
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Mains 90-147V, 190-252V, 50-60 Hz Battery 12V DC ± 2V Output 220V, 400 Hz Dissipation 70W Current 4A @ 12V DC
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Frequency 875 MHz ± 5% Pulse 1.2 µs Repetition 500 Hz (± 100 Hz) or 20 kHz (± 2 kHz) Output 10-35W or 350W (when MODE is set to 500 max) f2 suppression ≥ 100dB
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Sensitivity > 10dB Attenuator 0 to -45dB Dynamic range > 10dB Output 0.2 mW (speaker) f1 suppression ≥ 120dB
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Polarisation circular Aperture < 80° VSWR < 2 Gain ≥ 8dB
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According to the original Operating Instructions [A], the following items
were supplied:
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© Crypto Museum. Created: Saturday 27 October 2018. Last changed: Friday, 08 January 2021 - 17:25 CET.
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