Hello Dave and Marco,
reading your description, it seems to me that the 2355 is very similar to the
2155, may be an improved version (hopefully a more stable oscillator).
Yesterday I've connected the instrument to the LF antenna and it works well with
the 20 Hz BW. A little bit annoying is the ringing of the filter and the high
BFO Offset (1kHz).

73 de Toni

Dave Brown wrote:

Toni
If the 2355 is anything like the 2155 it should be very useful. The 2155 has
a selective receiver with 3.1 kHz and 20 Hz IF B/Ws  as well as a wideband
receive function for the full 200 Hz to 620kHz.  Using the 75ohm coax input
one can get the 0dB mark to correspond to -110dBm and read off at least 15
dB below that  reasonably accurately. A tracking oscillator covering the
full range up to 620kHz is included as well.
 If you cant get a manual ex Europe somewhere get back to me and I should be
able to help.
73
Dave
ZL3FJ