I prepare also a little converter (10.136mhz/136khz), because i think
that with only the FT847 direct on 136khz, and a dipole on 40 m, it 's not
the right way to hear something on this band, or am i wrong ??????
The best test is to see how you receive DBF39 on 138.830kHz. If this is
S9+40 or nearly there, your receive set-up is good. If you need more gain,
you may find a pre-amp is better than using a converter.
73 and welcome to the band Pascal.