18 Sep 2012
Since reverting to a passive double balanced mixer based design, the circuit is now behaving properly with no signs of oscillation and a good clean signal from the PA. Although I have used an SBL1 mixer, it will work with any similar mixer package. Tomorrow I may try the design with an NE602 as this would allow the separate oscillator to be removed. With an NE602 it should be possible to do the complete TX-RX transverter with 1 IC, 2 transistors and 1 FET. Now THAT would be neat.