Spycatcher Read Online Free PDF Page A

antisubmarine work. When sound waves impact with a taut surface such as a window or a filing cabinet, thousands of harmonics are created. The knack is to detect the point at which there is minimum distortion so that the sound waves can be picked up as intelligible speech.

    One day in 1951 I received a telephone call from Taylor. He sounded distinctly agitated.

    "We've been beaten to it," he said breathlessly. "Can we meet this afternoon?"

    I met him later that day on a park bench opposite the Foreign Office. He described how one of the diplomats in our Embassy in Moscow had been listening to the WHF receiver in his office which he used to monitor Russian military aircraft traffic. Suddenly he heard the British Air Attache coming over his receiver loud and clear. Realizing the. Attache was being bugged in some way, he promptly reported the matter. Taylor and I discussed what type of microphone might be involved and he arranged for a Diplomatic Wireless Service engineer named Don Bailey to investigate. I briefed Bailey before he left for Moscow on how best to detect the device. For the first time I began to realize just how bereft British Intelligence was of technical expertise. They did not even possess the correct instruments, and I had to lend Bailey my own. A thorough search was made of the Embassy but nothing was ever found.
    The Russians had clearly been warned and turned the device off.

    From questioning Bailey on his return it was clear to me that this was not a normal radio microphone, as there were strong radio signals which were plain carriers present when the device was operating. I speculated that the Russians, like us, were experimenting with some kind of resonance device. Within six months I was proved right. Taylor summoned me down to St. James's Park for another urgent meeting.

    He told me that the U. S. State Department sweepers had been routinely "sanitizing" the American Ambassador's office in Moscow in preparation for a visit by the U.S. Secretary of State. They used a standard tunable signal generator to generate what is known as the "howl round effect,'' similar to the noise made when a radio station talks to someone on the telephone while his home radio or television is switched on. The "howl round" detected a small device lodged in the Great Seal of the United States on the wall behind the Ambassador's desk.

    The howl frequency was 1800 MH, and the Americans had assumed that the operating frequency for the device must be the same. But tests showed that the device was unstable and insensitive when operating at this frequency. In desperation the Americans turned to the British for help in solving the riddle of how "the Thing," as it was called, worked.
    Brundrett arranged for me to have a new, secure laboratory in a field at Great Baddow, and the Thing was solemnly brought up by Taylor and two Americans. The device was wrapped in cotton wool inside a small wooden box that looked as if it had once held chess pieces. It was about eight inches long, with an aerial on top which fed into a cavity. Inside the cavity was a metal mushroom with a flat top which could be adjusted to give it a variable capacity. Behind the mushroom was a thin gossamer diaphragm, to receive the speech, which appeared to have been pierced. The Americans sheepishly explained that one of their scientists had accidentally put his finger through it.

    The crisis could not have come at a worse time for me. The antisubmarine-detection system was approaching its crucial trials and demanded long hours of attention. But every night and each weekend I made my way across the fields at the back of the Marconi building to my deserted Nissen hut. I worked flat out for ten weeks to solve the mystery.

    First I had to repair the diaphragm. The Thing bore the hallmarks of a piece of equipment which the Russians had rushed into service, presumably to ensure it was installed before the Secretary of State's visit. They clearly had some kind of