Spycraft - Melton [110]
TSD’s research chemists had run into one of Faraday’s Laws of Electrolysis. Paraphrased, the law states: The amount of total power in any given substance is proportional to the quantity of the substance. Even OTS scientists, as clever as they were, could find no loopholes in Faraday’s Law. When they wanted twice as much power, they needed twice as much of the substance. They could reduce the amount of the substance by half, and then get half as much power. Period.
One power source engineer explained the science to nontechnical case officers by saying, “You understand how electronics is shrinking the transmitter,” he said. “Well, when the transmitter is reduced one more magnitude, we’ll be able to disguise it as the label on this D-cell battery.”
Faced with Faraday’s Law, the designers of audio surveillance gear and covert communications became obsessed with power reduction. Instead of trying to pack more power into a smaller “can,” the engineers began looking for ways to minimize power consumption in the listening and covcom devices themselves. Less power consumption could be traded off against longer life or a smaller “can” or both. Reaching for the goal of a five-year operational life for battery-powered installations meant they needed to squeeze all the power possible out of each cell.
First among the breakthroughs was a series of switch receivers that allowed techs to turn a transmitter off and on remotely. Operationally, this enhancement ended the inefficiency of power wasted by transmitting signals from empty rooms. The remote on/off did not change the total hours batteries would power a transmitter, but it maximized the effective life by limiting transmission to those periods when conversations were held. “At three o’clock in the morning, we didn’t want that thing running, draining the battery life to send a signal that says, ‘There’s nothing going on,’” said Parker. “So, the listening post keeper could hit a button to turn on the audio in the room and listen. If something interesting was going on, if there was conversation, she’d turn on the tape recorder and continue monitoring. But if there’s silence, or she heard someone snoring, she’d turn the transmitter off.”
Remote on/off held another benefit. When a transmitter was switched off, sweep teams searching the radio spectrum for a bug would not be able to detect its presence. Equipment used by sweep teams to detect clandestine over-the-air transmitters in the 1960s looked for hidden metal objects and unauthorized radio frequency transmissions. Someone hunting for a bug could search the walls with a metal detector or modified radio receiver that automatically moved up and down the radio frequency spectrum seeking unknown or unidentified transmissions.
Because the on/off switch itself required some power to operate, it, too, became a candidate for additional power savings. One brilliant idea, the power saver circuit, came from an industrial contractor. The device was an extremely low power timer that turned the switch receiver to the on position for one second out of every twenty. If it did not receive a signal to start up the transmitter, the switch receiver obligingly went back to sleep for the next nineteen seconds. The savings in power was dramatic. Rather than running the switch receiver for twenty-four hours (1,440 minutes), the total time spent draining precious battery life could be reduced by more than 90 percent to just seventy-two minutes a day. Later, as portable, battery-powered devices began to multiply in the consumer marketplace, the same power saver circuit found a place in everyday products, such as pagers and cell phones.
The packaging of batteries presented another challenge for the techs. In some cases the battery’s gases and corrosive chemicals tended to leak. While corroded batteries in a flashlight or camera create an inconvenience for consumers, chemical reactions could prove disastrous for