TX Techniques TX FM1, Техническое руководство

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TX-FM1/S/R/A Technical Manual www.txtechniques.co.uk
4.5 Remote 'TA' Controller
The DTMF remote controller may be used to dynamically switch the RDS TA (Traffic
Announcement) 'flag'. The short burst of 'RDS ON' tones are used to activate the
RDS TA 'flag'. Ensure that the tones are clearly audible.
Music and/or voices played at the same time could prevent the tones from working.
If, after the TA mode has been activated, the 'RDS OFF' tones are not received
within 4 minutes, the TX-FM1/S/R/A will automatically cancel the TA mode. Abuse of
this system may incur penalties from the broadcasting Authorities.
It is important that the level of audio entering the TX-FM1/S/R/A, and therefore the
level of the RDS tones is 4dB. Whilst the DTMF detector has its own ALC
circuitry, it is 'ahead' the ALC and Audio Processor circuitry. If the signal is too low, it
may not activate the DTMF detector. Similarly, if the level is too high, it may be
distorted, and will not be correctly decoded by the DTMF circuitry.