Body wearable Stasi surveillance radio
The UFT-421 is a body wearable
covert transceiver built by
VEB RFT Funkwerk Dresden
in the former DDR (East Germany) in the late 1960s.
is rather large, but has a somewhat curved shape which allows
it to be carried on the body. It was intended for surveillance tasks
and was often used by the
Stasi (DDR Secret Police)
for observation of suspicious persons.
The UFT-421 was considered a special radio and as such it was listed
in the Handbuch Sondertechnik .
For concealed use, the radio was supplied with a
bracket with elastic straps,
so that it could easily be hidden under the operator's clothing. A cable,
that was usually running through the operator's sleeve, connected the radio
to a remote control unit that was
carried in the hand of the operator.
The image on the right shows the
curve-shaped transceiver of the UFT-421
(center) together with the remote control unit which is visible at the left.
The remote control unit holds the volume control, plus
two control switches: one for the receiver and one for the transmitter.
The UTF-421 was available in two frequency ranges: 33-88 MHz
and 146-174 MHz. The first radios entered service in the late 1960s
and the radios were produced well into the 1970s, until they were
succeeded by the much smaller Czechoslovakian
Tesla PR-35 FAUN in 1977.
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The UTF-421 was a two-way (simplex) radio, with a maximum of four channels
that were selectable with a rotary switch
on the main unit.
The unit was supplied with two antenna's: a rod antenna
and a wire antenna. The latter was an open dipole that could easily
be hidden under the operator's clothing.
The radio is powered
by 2 stacked 7.2V NiCd batteries (14.4V total).
The transceiver was supplied with two further accessories:
a vibrator unit
that could be carried in the pocket, and a
that was disguised as an
ordinary Mikki transistor radio.
Such radios were commonly used in the DDR at the time and would
not attract any attention of the public.
It allowed the operator to sit, say, on a bench in a park,
pretenting to be listening to a normal broadcast, whilst in
reality he was receiving his instructions. The vibrator was used to call
an agent who had his volume turned down.
The transmitter is controlled with a
three-position momentary switch
(see above) on the remote control unit.
In the center position, the transmitter is off.
The other two positions are: SmT (Senden mit Tonruf), for transmission with
selective call (tone), and SoT (Senden ohne Tonruf), for transmission
without selective call.
As the transmitter has a rather low RF output power (0.4 W),
the operational range was limited. Under ideal conditions
a maximum of 5 km was possible, but when the antenna was carried on
the body, the range was sometimes limited to less than 100 m.
The receiver is controlled by another
In the center position, the receiver is off. The other two settings
are: EmR (Empfang mit Rauschsperre), for reception with squelch, and
EoR (Empfang ohne Rauschsperre), for reception without squelch (i.e.
We are still looking for the operator's manual for this radio.
If you have this manual or if you have any other useful informtion
that can help us to expand this page, please contact us.
- Power: 14.4V DC ± 10%
- Current: 20-35 mA (RX), 145 mA (TX)
- Frequency range: 33-88 MHz and 146-174 MHz
- RF output: 400 mW
- Tone-call: 1750 Hz ± 50 Hz
- Dimensions (main unit): 210 x 120 x 35 mm
- Weight: 500 g
- Operational range: 50 m to 5 km (depending on antenna and circumstances)
- UTF-421 transceiver (main unit)
- Remote control unit with cable
- Dipole wire antenna
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© Crypto Museum. Created: Friday 30 March 2012. Last changed: Tuesday, 13 June 2017 - 17:51 CET.