Re: 6-gang FM stereo tuner heads
I have attached the comparison of different VNA measurement configurations and their relative error from 0.001ohm to 100K ohms. Clearly the transmission measurement is the winner compared with S11 measurement in DUT with high impedance. I cant remember where I got theses pictures from...
The third attachment shows the frequency sweep of my 6-gang FM tuner using the 0. 7pF Poorman's probe measured at the air variable capacitor of the last LC bandpass filter. Note the presence of the oscillator signal and noises from a powerful local London pirate station.
The 4th attachment shows my first attempt to measure the higher order harmonics of the 6-gang FM tuner oscillator with the poorman's probe measured at the frequency counter indicator is coupled to the BJT oscillator via a 1pF capacitor so there is little load pulling...
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