This photo shows the main amplifier with its three high gain MAR8 MMIC stages, followed by a fourth stage using a J310 transistor. The amplifier was made on a double sided pcb and each stage was carefully shielded with the same material. In order to make sure that only 144MHz noise is received, via the vhf input socket, the amplifier module was placed in a tinplate box, with tight fitting lids (top and bottom) and this, together with the DC meter amplifier board, was finally fitted into the blue case shown on the previous page The noise amplifier module is shown here inside its outer case. The other board in the case is the DC amplifier and meter circuitry. This was conveniently constructed on perforated board (Veroboard).  The equipment is powered by a 12V DC sealed lead acid battery rather than mains power as it is used primarily outdoors to check the constructor's antenna feedhorns and dish systems as well as to assess the noise performance of various  microwave transverters. Click here for the full, constructional article in PDF (Acrobat) format. RETURN TO FRONT PAGE MENU