measure ERP on 137.7 kHz
One of the major unkowns in transmitting on long wave band, is the real radiated power from the antenna. This information can be optained only by appropriately performed measurements. According to my very modest working conditions at a frequency of 137 kHz me this information is particulary interesting:
Antenna: inv. "U" 7 and 6 m. vertical, 27m. horisontal
the existing modest antenna, is the effective radiated power of
30 mW at 100 W tranmitting output . 30 mW ERP - this is probably
the real value.