Here we look at this 50 Watt RF PA as its reported to have no output RF power, we analyse the circuit (theory of operation) & carry out confirmatory tests to reveal the fault using the Rohde & Schwarz radio tester, we then make a number of measurements before trying a retune of the PA stages, this is followed by further analysis of the FM & SSB modes then we move onto the RX Low Noise Amplifier where we adjust its bandwidth & improve its gain, in making these measurements we carry out a number of detailed loss calculations of system components such as the amplifier pass thru mode & its losses in the test cables etc, we input that data as a reference level offset in the spectrum analyser & make further tests using the sweep tracking generator for absolute accurate measurements. finally we make harmonic analysis of the RX LNA & using external power attenuators of 3 & 30 db we calculate the TX power expected at the spectrum analyser & make changes to settings on the ESA spec ana to directly measure incident RF power of the PA. This is followed by a Harmonic analysis of the amplifier. There is a lot of detail we go into with regard to headroom, selecting the correct attenuator, calculating attenuation for the given incident RF power & establishing safe limits for the spectrum analyser RF input.

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