Decreasing the sensitivity of the radio

Decreasing the sensitivity of the radio

Soil Moisture Sensor

Turning down the gain of the radio receiver

When I started the project I didn’t know much about oscillators, dielectric constants, inductors, and so on. Now that I sort of know something about those things, I need to learn about radio receivers.

The first thing I stumbled across was the fact that the radio receiver has an inbuilt amplifier which is designed to boost the strength of potentially weak radio signals. I found out that the receiver has many different “gain levels” between 0 somethings and 49 somethings. The 0 and 49 are measured in somethings, because I don’t know what they are.

First up, with the gain set to 49, I can see the signal from the oscillator at just over 37MHz, but there are lots of other signals as well.

With the gain turned down to 28 somethings, it looks like some of the weaker signals are getting a bit… weaker.

Turning the gain down even further, to just over 1, almost all of the signals other than the oscillator have gone.

After I turned the gain off altogether, all I am left with is the oscillator signal, but there is an odd pattern of yellow and blue sections.

But I am interested in seeing whether the oscillator responds to evaporating gin, not learning about antennas and radio receivers work.

I have learned that I need to turn down the gain on the receiver if I want to isolate the signal from the oscillator.

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