Trev, I'm trying to figure out, if possible, the best way to graft the RF input port of a fully balanced mixer to a cathode follower, the mixer will be either the Minicircuits SBL-1 or the ADE-1, the mixer's RF in port is designed for 50 ohms input impedance, it's for a receiver project I'm trying to design (1.8 to 30 Mhz) The mixers VFO will be solid state but I want to use valves for the rest of the design.
From what I can gather the only way to step up that impedance for the frequencies concerned is with a wideband transmission line transformer, but apparently the maximum impedance step up ratio I'm likely to achieve if I make one of them is 1:4 (200 ohms) or possibly 1:9 (450 ohms) at a push, the grid input to the cathode follower will be parallel tuned circuit, loosely coupled to the antenna.
Any thoughts.
Lawrence.
From what I can gather the only way to step up that impedance for the frequencies concerned is with a wideband transmission line transformer, but apparently the maximum impedance step up ratio I'm likely to achieve if I make one of them is 1:4 (200 ohms) or possibly 1:9 (450 ohms) at a push, the grid input to the cathode follower will be parallel tuned circuit, loosely coupled to the antenna.
Any thoughts.
Lawrence.
