Secret Services & Spy Sets

Spy sets...I think that they're, actually, one of the most significant evidence of the technological progress of the time spell considered, which in this case is the second world war, because a spy,or more generally speaking a secret agent, doesn't have any certainty about what is going to happen to him, so he needs the best stuff to help him face all the possible scenarios and to work and report even in the most unprobable conditions...I know that now all these problems would make us laugh because of the incredible advance in tech in the last 20, but, at the time still they were a quite compelling issue to solve.

1. Spy Radio and Receiver Sets: once again the main problem was to permit spies abroad to comunicate safely and as frequently as possible...To achieve this result all nations developed their own radio, like the RSZ, developped by US Navy around 1943, a small self-contained receiver with an external battery pack in a similar housing, that could be carried on the chest in a canvas case with two pockets; or the URSS Elektron Radio Set, characterized by a output power of 50W, suitable for ranges up to 3000 km and one of the first true spy radios to used a burst encoder in order to minimize the risk of interception and detection by the enemy (LPI). Other examples are: from UK, the Type A Mk. III (A3), a small spy radio set, manufactured by the Marconi Company in the UK in 1944, close towards the end of WWII. It was intended for clandestine operations on occupied territory, by agents, special forces and resistance units (S.O.E); or from Japan the incredible 94-6, a miniature single-valve portable transceiver that was used during WWII, as part of a series of Army radios.
   
2. Covert Cameras or Minicameras: we've already spoke about this item in the posts  Minicameras...micro optics at the service of the spies and Minicameras 2.0, but if you wanna go further go on and check the web page in the crypto museum dedicated to them
3. Covert Recorders:
   
   high-precision portable minature wire audio tape recorder, which could have been easily hidden under everyday cloathing. As a matter of fact this kind of Covert Equipement, like recorders and, especially bugs, belong more to the post WWII period, around 1950 and following decades, in fact their structure is much different from their precedent, because there were different needs and purposes which must had been considered during their fulfilment. Two  exemplar models are the Nagra SN (in the photo), introduced in the 1970, used by both CIA and Stasi and capable of recording in sync with a videocamera, and the Protona Minifon Attaché, a miniature tape recorder, using a magnetic tape which was organized into cassetes produced by the Protona GmbH, since the Philips Compact Cassettes weren't yet available.
4. Burst Encoders: device that allows messages to be stored on a recording medium first. The pre-recorded message is then sent over the air at very high speed using a play-back device. Many solutions were developed, using a variety of media, such as paper, audio tape, metal tape, mechanical drums and even photographic film.   Messages that are sent this way often sound like a short tone or burst, which is why it is called a Burst Transmission.
   
5. Bugs: Once again we're making a step forward in history, of 15-20 years more or less, but still its important to define them as a foundamental element of the spy set. One of the earliest sample of this incredible piece of technology is the KBG bug, a small radio bug, introduced around 1964 , with dimensions 72x23x10 mm, so  really small, as it can be inferred by the photo below... but there were smaller and more sophisticated prototypess such as the PS-006, a bollpiont bug developped in the 80's and with a small radious of action, only 25 m due to the small voltage
   

Click on the light blue words to link with pages where you can find more specific description about each single prototype and examples of others similar devices.

Sources:
http://www.cryptomuseum.com/spy/index.htm
http://en.wikipedia.org/wiki/Low_probability_of_intercept