This Band pass filter and amplifier is centered on 55Mhz with a 1 meg band width, the response is reasonably good with no more than 1 db variation over that range.
The gain of the filter unit is around 15 db. There are matching transistors at both the input and output of the filter. The main gain stage is a dual gate mosfet, it helps to make up for the signal loss through the diode balanced mixer. The unit as pictured is basically a receiver front end convertor which comprises a diode mixer up conversion, 55 meg filter, and a diode mixer down conversion stage. This all seems to test ok so far.
The gain of the filter unit is around 15 db. There are matching transistors at both the input and output of the filter. The main gain stage is a dual gate mosfet, it helps to make up for the signal loss through the diode balanced mixer. The unit as pictured is basically a receiver front end convertor which comprises a diode mixer up conversion, 55 meg filter, and a diode mixer down conversion stage. This all seems to test ok so far.
