[hpsdr] mercury arrived - noise floor

[Georg Prinz]

Hello everybody,

I got my mercury and fired it up successfully. Nevertheless I realized
that the noise floor is about -95dBm and the RX-meter shows -101,5dBm
when the input is shortened with 50 Ohms. 

Is this behavior ok, because the whole system is sitting on my workbench
without any screening case?  The power is taken from a ordinary
labor-supply.

How can I lower the noise floor?

Thank you in advance.
Georg, dl2kp