472kHz preamp

As mentioned some days ago, I received a 472kHz preamp from a very kind, anonymous, person recently. In the next few days I need to check FT817 sensitivity with and without the preamp. Assuming it makes a very useful difference, I'll try 472kHz WSPR receive to see what I can copy using the earth-electrode antenna at this time of year when the LF and MF bands are still quite noisy.