Help with FM tuner Signal injection/probing
Hi,
Does anyone have any tips on how I should inject signals into and probe for signals in an FM tuner?
For instance how would I correctly inject a 100 MHz 100uV (-67dBm) RF signal from a signal generator (Marconi 2022E 50 ohm output impedance) into a 75 ohm antenna input? Is it best to set the input impedance of the oscilloscope (which I'm using to measure this input voltage) to 50 ohms or 1 Meg Ohm? What kind of loading effects can I expect.
Also, what is the best way of probing the Circuits in the tuner without introducing any significant loading. Likewise, what is the best way of injecting signals? I ask these seemingly simple questions as I am not experienced in aligning receivers and I want to learn. Hope someone can help. Thanks.
PS I'm using standard 75 ohm BNC connectors and coaxial cable. What effect will this have on my measurements.
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