|
|
|
|
|
|
|
SBO SF BRD NL BND FSS-7 →
Modular hybrid spy radio set
SP-15 is a modular hybrid 1
agent communication set, also known as a
spy radio set, developed around 1958 by the German intelligence
service Bundesachrichtendienst (BND)
and manufactured by Wandel & Goltermann in Reutlingen (Germany).
It was used for espionage, diplomatic traffic,
Special Forces (SF), clandestine (covert) operations and
Stay-Behind Organisations (SBO).
Certain components of the SP-15 radio station were also used by partner
organizations and agencies in other countries.
In The Netherlands, SP-15 was used by the SBO
O&I, and was known as FSS-7. 2
|
A complete SP-15 radio station consists of an FE-8 receiver,
an FSS-7 transmitter,
a high-speed morse burst encoder,
an AC mains power supply unit
a 12V DC battery power supply unit,
various battery chargers, crystals and one or two boxes
with accessories, spare parts and tools.
The image on the right shows the transmitter (right), the DC PSU (centre),
the receiver (left), a morse key (front right) and various accessories.
The set was often supplied with a
burst encoder for high-speed transmissions in
morse code,
to minimize the chance of
direction finding (RDF).
|
|
|
 |
-
In this context, hyrid means that it contains both valves (tubes)
and transistors.
-
FSS-7 is actually the designator of the transmitter, but in The Netherlands
it was used for the complete set. The designator (FSS-7) is sometimes
erroneously written as FS-7 or FFS-7.
|
|
|
Transmitter
FSS-7 · BN-22
|
|
|
The transmitter of the SP-15 was developed by the
Bundesnachrichtendienst (BND)
around 1958 and manufactured by Wandel & Golterman (W&G) until 1962.
In Germany it was known as FSS-7
or BN-22.
It has two valves (EL95 for the oscillator and EL81 for the HF power amplifier)
and one transistor (OC450) and is suitable for CW only.
Power output was 10W or 20W, switchable from the PSU (see below).
The transmitter is crystal operated, but the
Dutch version (FSS-7/NL)
was later modified for use with a synthesizer.
➤ More information
|
|
|
The FE-8 receiver was developed around 1958 by the
Bundesnachrichtendienst (BND)
and was manufactured by Wandel & Golterman (W&G).
It can be used in combination with the FSS-7, but
also as a standalone receiver. Power is provided by an
internal battery, or by an external source.
The receiver has two ranges (2.5-9.1 MHz and 9.1-24 MHz) with permeability
tuning, resulting in a linear scale for both ranges. This receiver
was also used with the later SP-20 radio sets.
➤ More information
|
|
|
|
|
Receiver UHU
BN-48 · FE-9
|
|
|
For situations where the wide frequency range of the FE-8 was
not needed, the smaller FE-9 was used, which covers the lower
frequencies only (2-9 MHz). The reduced size and weight made it
easier to smuggle the device into a country.
The FE-9 (codenamed UHU) is suitable for the reception of AM and CW (morse) signals.
It was developed by the
Bundesnachrichtendienst (BND)
and built by Wandel & Golterman (W&G).
➤ More information
|
|
|
The SP-15 was supplied with a highly compact mains power supply unit (PSU)
that was suitable for all common AC mains voltages in the world, between
95 and 235 V. It produces the LT and HT voltages for the transmitter.
It is slotted into the left side of the transmitter or, in the case
of the modified Dutch FSS-7/NL, into the left side of the
special junction box.
➤ More information
|
|
|
When no mains AC network was available, it was also possible to power
the SP-15 from a 12V DC source, such as the battery of a car. This was done
by swapping the AC PSU for a DC one.
It contains a power inverter that converts the 12V DC input into 6.3V
for the filaments and a HT AC voltage for the transmitter's valves.
Like the AC PSU, it is slotted into the left side of the transmitter.
It contains a relay to prevent the DC power source from being reversed
accidentally.
➤ More information
|
|
|
|
The FSS-7 transmitter operates on fixed frequencies as determined
by a quartz crystal. Several crystals, for pre-determined BND channels,
were supplied with the set. The were either supplied in a blue carton box
or in a small grey hammer-paint metal container.
...
|
|
|
For burst transmissions at very high speed, such as the 1200 baud
mode of the MMP burst encoder shown above, the existing keying methods
were not adequate and this primitive FSK Modulator was developed as
an alternative.
It was inserted between the crystal and the crystal socket of the
FS-7 transmitter.
➤ More information
|
|
|
The analogue scale of the FE-8 (BN-58) receiver can be calibrated with
this external calibrator, that is connected to the receiver's antenna
and ground sockets.
It is powered by an internal 6V battery, which is
identical to the one used in the FE-8 itself. It was supplied with the
SP-15 sets that were used in Germany.
➤ More information
|
|
|
The SP-15 came with a large number of accessories, some of which are
shown here.
The most remarkable one is the surprisingly cheap looking morse key,
made of a rather poor quality plastic.
In use, the key is not as bad as it looks as it's rather heavy.
Furthermore, the plastic is shielded on the inside.
Other accessories include antennas and cables.
|
|
|
For use by special forces and reconnaissance units, a special webbing
pack was developed that allowed the various units to be worn on the
chest. The webbing pack had a pocket for the transmitter and power
convertor and another one for the receiver and the accessories.
Power for the set was delivered by a separate (heavy) battery belt
that would be worn around the waist.
The belt contained 10 rechargeable NiCd batteries of 1.2V/10Ah each.
|
|
|
|
In order to reduce the chance of detection and interception
by means of Radio Direction Finding (RDF),
the SP-15 was often used in combination with a so-called
burst encoder.
It allows a pre-recorded message to be played back —
commonly in morse code —
at very high speed.
As the transmitter is only on the air for a very short moment,
there will be less chance to do a proper triangulation and
locate the radio station, which would have endangered
the entire operation.
|
In the early days of the SP-15, the burst encoder of the predecessor,
the KSG-Sender,
was used to send short messages of 20 to 25 digits
in morse code. The KSG consisted of a metal disc in which a number
of mechanically coded inserts had to be installed.
A crank was then used to rotate it.
➤ More information
|
|
|
The second burst encoder to be issued with the SP-15 was this
electro-mechanical RT-3 unit.
A small military-grade metal box that allowed a message of
25 characters to be stored mechanically. Once on-air, the message
was played back by operating a hand crank.
Later, more advanced burst encoders were issued, such as the
GRA-71,
MMP
and Speicher.
➤ More information
|
|
|
For a long time, the SP-15 was used in combination with the
American military GRA-71 burst encoder that allowed the dots and
dashes of the morse characters to be recorded on a piece
of ferro-magnetic (audio) tape.
Especially for use with the SP-15, they were supplied
in grey hammerite, rather than the usual black as
used by the US Army.
➤ More information
|
|
|
The Speicher (Eng: memory) was a fully electronic burst encoder
for sending numbers at high speed in morse code. It was powered
directly from the mains and was housed in a similar case as the
SP-20 spy radio set.
The Speicher was probably issued in the 1970s to replace the
rather limited RT-3.
Eventually it was replaced itself by the
more advanced MMP.
➤ More information
|
|
|
The MMP was a fully electronic high-speed (1200 baud) burst
encoder that was used with both the SP-15 and the
SP-20 spy sets.
The MMP replaced older devices, such as the mechanical
RT-3,
the American AN/GRA-71
and the early electronic Speicher.
It could hold more than 1000 letters and numbers in its battery-backed
CMOS memory and send them at various speeds between 15 and 1200 baud.
➤ More information
|
|
|
Modified FSS-7 used by Dutch Stay-Behind
In The Netherlands, the SP-15 was used for the national
Stay-Behind
organisation
O&I (Dutch: Operatiën en Inlichtingen)
during the 1960s and 1970s.
O&I agents were given two green water-tight containers that could be
burried underground, e.g. in the garden of their house. One of these contained
a hand gun, ammunition, cash money and gold (the latter for bribing people).
|
The other one contained the SP-15 radio set,
together with a wide range of accessories
such as antennas, crystals, spare parts and a burst encoder.
The image on the right shows a typical modified Dutch FSS-7 (SP-15)
with synthesizer.
Around 1975, the set was given a mid-life upgrade by the addition
of a synthesizer for the transmitter and a purpose-built junction box.
➤ More information
|
|
|
-
Document kindly provided by Jim Meyer [1]
|
- Helmut 'Jim' Meyer, HS0ZHK, My way to Ham - Radio and beyond
Website QRZ.COM. Personal correspondence.
Retrieved April 2013.
- Museum Jan Corver, Exhibition Secret Messages
The Dutch version of the SP-15 was on display during this exhibition.
- Louis Meulstee, Wireless for the Warrior, volume 4
ISBN: 0952063-36-0, September 2004.
- Museum Verbindingsdienst, Burst Encoders for Stay-Behind use
Dutch Signals Museum.
Photographed by Crypto Museum. 25 February 2009.
- Geschiedenis van de Sectie Algemene Zaken, Hoofdstuk VI, Consolidatie
History of the Section General Affairs, Chapter 6, Consolidation.
pp. 79 - 80 (Dutch)
Describing the period May 1970 - December 1981.
Dutch National Archives. Top Secret.
Partly declassified and released in 2007 under the FOI Act.
- Armin Müller, Wellenkrieg
ISBN 978-3-86153-947-6, June 2017. pp. 100—103.
- Detlev Vreisleben, Personal correspondence
Retrieved May 2018.
|
|
|
|
Any links shown in red are currently unavailable.
If you like the information on this website, why not make a donation?
© Crypto Museum. Created: Monday 03 August 2009. Last changed: Sunday, 09 June 2024 - 22:28 CET.
|
|
|
|
|
