I mentioned in my previous update that following my noise floor measurements I tried connecting antenna to the receiver input through C27 but did not have any signals through. Today I found out that I had a bad solder at L11 and so the antenna switcher wasn’t working.
Re-soldering the connections helped a lot and I can now receive all bands as shown on the screenshots below.
I also found that some settings of the Si570 give more noise in the passband than others. On the screenshot below we see a lot of noise occurring when the frequency is set to 14.232 MHz whereas there was practically no noise when the frequency was set to 14.243 MHz.