Thanks Warren, that seems a very good and promising news. MMICS really simplify circuits and will probably improve the overload specs of the receiver too. If ground loops might be possibly a problem simple 1:1 isolating transformers might be used. I look forward to seeing this tricycle better than some Ford in terms of IMD!
Il 15/set/2018 17:19, "Warren Allgyer" <
allgyer@...> ha scritto:
As an aside, I tested this particular MMIC board for its susceptibility to oscillation. I connected a 60 dB attenuator between the input and output while I fed a signal to the input. I gradually reduced the attenuation one dB at a time until oscillation was visible on a 1.5 GHz spectrum. The amplifier broke into oscillation very reliably when the attenuation was stepped below -14 dB. Higher than that and it was completely stable.
In the course of these two tests the board was hanging unshielded about 3 inches from the PA heat sinks and the output was a little over 4 watts. In both cases I saw no indication of oscillation.
WA8TOD
