The Northern mast is 165 metres high and is the main antenna, which can broadcast a maximum signal of 300kW on 927kHz.
The Southern mast is 080 metres high and is the main antenna, which can broadcast a maximum signal of 600kW on 1512kHz., or a 300kW signal on 927kHz. if the 165 metres high mast is undergoing maintenance.
The other two masts are 090 metres high and are used for the "curtain-antennas", which are a backup for the 1512kHz. and can produce a 600kW signal. One of those masts is also a backup antenna (at 045 metres hight) which is capable of broadcasting a 050kW signal.
Under normal circumstances the ERP is as follows:
927 kHz : 180kW (backup is 020kW)
1512 kHz : 025kW during daytime hours, 300kW at night
