| 摘要 |
To ensure prompt contact between a football linesman and the referee, a signal flag used by the linesman has a handgrip (1) in which is fitted a transmitter, that causes a receiver carried by ther referee to be activated. The transmitter is press-button operated (6) by the thumb of the linesman, and there is a delay of one second between the button being depressed and the production of a transmitted signal. - The range of the transmitter is limited to 180 to 200 metres, and the transmitter is uniquely coded, with the receiver having a code key of the plug-in type with the same unique code. |
