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CIA spy radio set
TAR-224 was a very compact, fully self-contained transceiver, developed
by AVCO Corporation in Cincinnati (Ohio, USA) around 1970
for the CIA.
It was intended for communication with field agents operating behind
enemy lines, and can be seen as a successor to the ageing
GRC-109 (RS-1) of the 1950s.
It was used for many years until it was phased out in the late 1980s.
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The entire unit is completely waterproof, with all switches and controls at
the front panel properly sealed, allowing the radio to be stored under
harsh conditions for an extended period of time. A plastic lid can be placed over
the controls to protect them against dust and dirt. It is held in place by
three metal latches at the edges.
The image on the right shows a typical TAR-224A unit, without the optional
CS-224 30-channel crystal selector installed. The unit roughly consists of
two parts: the receiver (RX) at the left,
and the transmitter (TX) at the right.
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The radio coverages all frequencies between 2 and 24MHz. The receiver has
a Variable Frequency Oscillator (VFO), allowing continuous tuning of all
4 frequency bands, whereas the transmitter is crystal operated.
The unit can be powered by an external 12V source that is connected
to a 3-pin socket at the front left, or by a special
12V battery pack that is installed behind a watertight panel
at the front left. A plastic grip,
at the left of the radio, allows the unit to be carried around easily.
The TAR-224 was introduced in 1970 and the user manual was updated
once in September 1971. The unit shown here, was probably issued in the
early 1970s, and was last inspected in 1976.
Most TAR-224 units were used by the CIA on special (overseas) missions [4],
but the radios were also used by intelligence services in Europe [1].
It is known to be used on a mission in Angola in 1975.
According to CIA communication specialist Teddy Roberts, the TAR-224
was still being used in operational context in 1983, when he trained
a unit of US Army Green Barets on its use.
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The image below gives a good view of the TAR-224 controls and connections.
The left half of the radio contains the receiver (RX), whilst the right
half contains the transmitter (TX). The two sections are separated by a
vertical white line at the center. The radio can be powered by an internal
12V battery, but also by an external power source that is connected at
the bottom left.
The receiver has a Variable Frequency Oscillator (VFO) that can be adjusted
to any frequency between 2 and 24MHz, but the transmitter requires a suitable
crystal for each TX frequency. The crystal is inserted into a special socket
at the bottm of the TX section. At the top right is room for an expansion
unit. As far as we know, the only expansion that was ever released was the
CS-224 crystal selector that allowed quick selection of 30 channels
(the option is not shown here).
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At the bottom of the front panel
are the MODE-selector,
the Beat Frequency Oscillator (BFO),
AF gain (volume) and RF gain (HF pre-amplifier).
When the RF adjustment is set to the leftmost position, the Automatic
Gain Control (AGC) is enabled.
The receiver also contains the POWER switch
and the connectors for
external power, microphone, speaker and external morse key.
The frequency scale can be calibrated by setting the MODE-selector to
CAL. This enables the built-in reference oscillator, which produces
a carrier at 500kHz intervals (3MHz, 3.5MHz, etc.).
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Once the reference oscillator is selected, tune the receiver to a carrier near
a rounded frequency (e.g. 3MHz) and
adjust the scale ruler (CAL ADJ) so that its
center positions lines up with the frequency.
The receiver is suitable for the reception of morse signals (CW)
and voice (AM), but can also receive Single Side Band signals (SSB)
by the using the built-in Beat Frequency Oscillator (BFO). For normal
operation (CW) the BFO should be set to the center position (0).
For SSB signals, the BFO knob can be tuned
(-) for Lower Side Band (LSB) and (+) for Upper Side Band (USB).
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The transmitter is crystal-operated and is
suitable for CM (morse) and AM (voice) communication. A suitable
CR-18/U crystal can be inserted in a special socket at the front center.
If rapid channel selection is needed, an optional channel selector
can be installed in a special slot at the top right. If the selector
is not installed, the slot is closed by a thick plexiglass panel.
The manual suggests that a synthesizer could be installed as well,
but as far as we currently know it was never built.
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When using the (optional) channel selector, three banks of 10 channels
each are available. When a single crystal is inserted into the
crystal socket at the front panel, the 30-channel selector
is disabled.
Two frequency ranges are available via a selector:
2-12MHz and 12-24MHz.
In the 12-24MHz mode, the crystal frequency is doubled.
When sending messages in
morse code, the TAR-224 was normally used
in combination with a burst-encoder in order
to avoid detection and interception by a potential eavesdropper.
It was probably used with the
GRA-71 burst encoder.
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Alternatively, a morse key could be connected to one of the
6-pin U-229 connectors at the front left,
allowing manual transmission of morse signals. In case of an emergency,
the built-in morse key could be used for
this as well. The minimum output power for an unmodified TAR-224 is specified
at 13W in CW and 4W in AM, but in practice the output power was much higher.
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The radio shown here delivers 21W in CW and up to 8W in AM [3].
When used for phone (voice), a handset or
headset could be connected to one of the 6-pin U-229 sockets
at the front left.
The (wire) antenna and a suitable counterpoise should be connected
to the two snap-on terminals
at the right edge of the transmitter.
The TAR-224 has a built-in Antenna Matcher that allows the transmitter
to be adjusted for the (wire) antenna in use. This can be done by
holding down the morse key whilst manually rotating the antenna
tuning knob at the right.
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Alternatively, the Automatic Antenna Tuner (AAT) can be enabled by
pulling-out the antenna matcher knob.
This engages a novel motor-driven
coil mechanism that tries to obtain the highest power output at the
best possible Standing Wave Ratio (SWR).
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The TAR-224 can be powered by any 12V DC source that can deliver 5.9 Amp.
The operational voltage range is 10.8 to 13.2V. When using an external
DC source, the so-called battery-protection circuit automatically
disables the internal battery in order to prevent damage.
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When a suitable power supply/battery charger is used,
it can be used to charge the battery simultaneously. For this purpose,
a separate contact is used in the connector and the battery.
The battery itself is a single-unit rechargable 12V accumulator
that is installed behind a water-tight door at the front left
of the radio. In the battery compartment are three contact pins,
marked J1, J2 and J3. The first pin (marked J1) is connected to the +12V
whilst J3 is connected to the negative terminal (-) of the battery.
The center pin (J2) is for charging the battery.
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Please note that the battery-protection circuit uses a latching
(bistable) relay. Once the internal battery is switched off, it will
remain disabled (even when the external power source is removed)
until the RESET POWER button on the front panel is pressed.
Please note that when putting the radio in storage,
the power selector
at the front panel should be set to the OFF position (left).
When closing the radio,
an index stub
on the inside of the top
cover prevents it from being fitted when the power switch is not
in the correct position (OFF). The top cover is locked in place
by means of three latches at its sides.
When put in the upright position,
the radio can be carried around using the
plastic grip at the side.
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The TAR-224 is a truely compact self-contained transceiver. The entire
radio is housed in a die-cast aluminium case that measures approx.
12 x 18.5 x 31 cm and weights just 6 kg. The case is fully waterproof
and all controls, connectors and adjustments have watertight gaskets.
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After loosening 10 torx bolts at the edges of the front panel, the entire
radio can be lifted out of the case.
The image on the right shows the interior of the radio with the front
panel facing down. At the left is the transmitter with the coils of the
Automatic Antenna Tuner clearly visible (the preotective cover is removed
here).
At the right is the receiver and (at the front) the internal wiring of
the various controls at the front panel.
The construction of the receiver is extremely complex. It is attached
to the front panel with just four bolts and can easily be removed.
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The receiver is connected to the rest of the radio with only
one 29-pin connector.
After removing the knobs and the four bolts from the front panel,
the entire receiver can be lifted from the connector
and, hence, the interior. The RX block consists of a series of
shielded units that are bolted together. They are wired together via
two (green) 14-pin connectors at the side.
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The image on the right shows the RX unit with the frequency scale
facing upwards. The 29-pin connector and the two 14-pins connectors
are visible at the left. A separate SMC connector is used for the
RF antenna input (at the front).
In order to accomodate the four frequency ranges, a complex contruction
is used for the Antenna Matching unit, the RF pre-amplifier and the
Local Oscillator (LO). These three units are mounted side-by-side in
a single enclosure, with a common axle (attached to the BAND selector)
running through each compartment.
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As each of the three units has to be adjusted differently for each
frequency band, four different tuning sections are mounted around the
common axle in each compartment. When rotating the BAND-selector
at the front panel, the axle turns 90° with each step, selecting
a different section.
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The image on the right shows the interior of the three units.
The tuning section are clearly visible at the center of each compartment.
The rotation from the BAND-selector is carried over to the common axle
by means of a serial of
cogwheels and a chain belt
at the side of the receiver.
The tuning section is normally closed by a common metal plate that
covers the three sections (the cover is not shown here).
The signals from the HF pre-amplifier and the Local Oscillator (LO)
are fed to the IF-stage that is mounted
to the bottom of the receiver unit.
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The right half
of the TAR-224 contains the transmitter (TX), of which the
Automatic Antenna Tuner (ATT) is arguably the most interesting unit.
It is mounted in the front right corner
of the radio. It consists of a large adjustable capacitor and
a very special variable tuning coil.
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The image on the right shows the ATT after its protective
cover has been removed. At the left is the tuning coil.
It is connected via a cog wheel mechanism at the bottom,
to a synchronized rigged solid metal spool behind it.
At the front right is the electro-motor.
It drives the tuning mechanism at 1000 RPM.
Also connected to the mechanism is the large tuning capacitor
that is just visible behind the motor.
When enaging the ATT (by pulling the knob at the front panel),
the tuning capacitor and the coil are adjusted for
optimum SWR.
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A novel winding/unwinding mechanism is used
for the adjustment of the coil. When running, the wiring is moved from
the coil to the solid spool and vice versa. As a result the
induction of the coil is increased or decreased.
When starting the ATT, the mechanism is first wound back completely
(0-position). It then runs forward until the desired position
is reached.
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The diagram below shows the pin numbering and connections of the connectors
at the front left of the TAR-224. The two U-229 sockets (left) are identical
[5].
They both are fully wired (A-F) in parallel. The other socket (right) is the
socket for the external power source. A suitable connector for the latter is
the Amphenol PT06A-8-3S, which is available from distributors like
Digi-Key (US).
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| Pin
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Function
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Description
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| A
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GND
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Ground (common wire)
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| B
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SPK
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Speaker (separate, or part of handset/headset)
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| C
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PTT
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Push-to-Talk switch (connects to ground)
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| D
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MIC
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Microphone (separate or as part of handset)
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| E
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KEY
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External (morse) key
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| F
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+12V
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Power supply (output) for external burst encoder
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| Pin
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Function
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Description
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| A
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+12V
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Power supply (input)
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| B
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GND
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Ground (common wire)
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| C
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CHG
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Charge input (for internal battery)
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| Pin
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Function
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Description
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| J1
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+12V
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Power supply (input)
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| J2
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CHG
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Charge input (for internal battery)
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| J3
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GND
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Ground (common wire)
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Terry Roberts worked for the CIA for 40 years 1
Teddy Roberts started his professional life back in 1960 when,
fresh out of high school,
he attended a Radio Intercept Operator's Training
in Imperial Beach (California, USA).
After passing a Naval communications training later that year,
he got his first assignment at the US Naval Communications
Facility in Adak (Alaska), where he learned to work with
sophisticated high-powered computers, video display terminals
and the collection and analysis of communications signals.
In 1963 he was transferred to the Naval Communications Station
in Honolulu (Hawaii).
In 1964, following his release from the US Navy, Terry
entered communications training with the CIA, after which he
was assigned to the American Embassy in East Africa.
Later that year, whilst being on medical hold for any overseas posting,
Terry was temporarily assigned with an engineering office at
the CIA's communications training facility.
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After his medical hold had been cancelled in 1965,
he was assigned to a US Embassy in West Africa.
In the following years, he worked in several countries
including Germany, Libya, Israel, the Phillipines,
and China, until he landed in London (UK) for a five-year
assignment with the US Embassy. During these years he worked
closely with the British Intelligence services in support
of NATO war planning programs.
In 1988, he was assigned to CIA Headquarters in
Virgina, where he worked as chief of recruitment for the CIA's
Office of Communications. A few years later he was assigned
as Deputy Chief of Operations
of the Communications Area Operations staff for Africa.
In 1992, Terry was assigned as associate director of the
CIA's Global Network Management Center, planning the CIA's
world-wide communication needs on a daily basis, until he
retired from the CIA in 1995.
The image on the right shows Terry Roberts holding a TAR0224A in
his hands. He used this radio in an operational context in 1983,
when training a unit of Army Green Berets on its use.
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One of Terry's most memorable experiences was his involvement
in the arrest of Daulton Lee and his partner in crime
Crystopher Boyce, during his three-year tour in Mexico
where he worked closely with the FBI.
Whilst working for the US defense contractor TRW,
Boyce copied classified government information with a
Minox-B spy camera,
which Lee sold to the Soviet Union.
Lee and Boyce were eventually arrested in 1977,
and were sentenced to life and 40 years respectively.
The story was later told in the 1979 book
(and later in the 1985 movie)
The Falcon and the Snowman.
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Thanks to The Journal for allowing us to reproduce part of their
2009 publication [4] and the photograph above.
The photograph was made by Elaine Blaisdell, who also wrote the
original article.
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Although the TAR-224 was in service for many years during the Cold War,
not many of them have appreared on the surplus market, making them into
rather rare collector's items. As a result, not much is known about the
backgrounds and operational context of these radios. If you have any
information that is not listed here, please contact us.
We are also looking for the optional CS-224 Channel Selector that
can be installed in the empty slot in the top right corner of the radio.
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© Copyright 2009-2013, Paul Reuvers & Marc Simons. Last changed: Sunday, 04 May 2014 - 23:20 CET
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![Photograph by Elaine Blaisdell. Copyright 2009, The Journal [4]. Reproduced here with kind permission.](img/TerryRoberts.jpg "Photograph by Elaine Blaisdell. Copyright 2009, The Journal [4]. Reproduced here with kind permission.")