TFA 30.3029 Manual Del Usuario página 117

Note:
After the three transmitters have been set up, user may need to check the readings
displayed on the weather station against those being shown on the transmitter
displays, in order to recognise on which channel each transmitter is being
presented.
IMPORTANT:
Transmission problems will arise if the setting for additional transmitters is not
followed as described above. Should transmission problems occur, it is necessary
to remove the batteries from all units and start again the set-up from step 1.
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