| 摘要 |
A remote alarm system for transmitting an alarm signal to a remote receiver when unauthorized access to a given installation is attempted. A remote portable radio transceiver is capable of receiving signals through the atmosphere from and transmitting signals through the atmosphere to a stationary radio transceiver which is operatively tuned to the remote transceiver for also receiving and transmitting signals from and to the remote transceiver. The stationary transceiver is located at the installation which is to be protected against unauthorized access, and a source of electrical energy is connected with the stationary transceiver. Connected to the installation as well as to the stationary transceiver is a switch for responding to an attempted unauthorized access so as to transmit a signal from the stationary transceiver to the remote transceiver. At the remote transceiver is an alarm which responds to the latter signal for warning the carrier of the remote transceiver that an attempted unauthorized access is being made at the installation.
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