|This is my current (2003) antenna configuration for 136 kHz. It's consists of a 10m fiber pole which is coming out of the window of the attic with 2 * 15m toploads (made of 0.32 mm insulated copper wire), which are parallel, spacing about 10cm. The difference to a single wire only is tremendous - the size of the loading coil could be decreased and the performance increased. The loading-coils are also in attic (see picture). At about 14m, there is an elevated 1 mH basket-weaver coil.
The antenna can be erected in less than 5 minutes and works much better (about 10 dB) than the doublet which I tried to tune up on LF before. The ground-system only consists of the water piping of the house.
ERP with 35 Watts input should be about 10 mW (tant136.exe), antenna current is about 500-700 mA.