Preamplifier for RF Sweep Generator

The RF sweep frequency generator (‘wobbulator’) published in the October 2008 issue of Elektor has a receiver option that allows the instruments to be used as a direct-conversion receiver. This receiver does however have a noise floor of only –80 dBm, which really should have been –-107 dBm to obtain a sensitivity of 1 µV. So, for a good receiver some more gain is required.