Click on pictures to Zoom in. Please go to the website of W7IUV for the schematic diagram of this preamp: w7iuv.com
LTSpice model frequency response of W7IUV preamp using 1uf coupling and bypass capacitors.
Source = 0.1uV peak with internal resistance = 50 ohm.
At 1.8 mhz the input delivered to amplifier using this source = 0.0481 uV peak, and output across 50 ohm load = 0.585uV peak.
Output amplitude in dB relative to 1 volt peak at 1.8 Mhz : 20 log (0.585uV / 1V) = -124.66 dB as shown below in the frequency response curve.
Gain = 20 log (0.585uV / 0.048 uV) = 21.70 dB
Note : The Ferrite toroid core material was not taken into account, and it was modeled as if it were air.