- Joined May 12, 2016
would i able to amplify raido wave with 2N2222 transistor?
It depends on the frequency. What frequency did you have in mind?would i able to amplify raido wave with 2N2222 transistor?
It depends on the frequency. What frequency did you have in mind?
The transition frequency is in the range of 250-300 MHz. In order to be useful as an amplifier it must be used at a much lower frequency.
For transistors, the current-gain–bandwidth product is known as the fT or transition frequency. It is calculated from the low-frequency (a few kilohertz) current gain under specified test conditions, and the cutoff frequency at which the current gain drops by 3 decibels (70% amplitude); the product of these two values can be thought of as the frequency at which the current gain would drop to 1, and the transistor current gain between the cutoff and transition frequency can be estimated by dividing fT by the frequency. Usually, transistors must be applied at frequencies well below fT to be useful as amplifiers and oscillators. In a bipolar junction transistor, frequency response declines owing to the internal capacitance of the junctions. The transition frequency varies with collector current, reaching a maximum for some value and declining for greater or lesser collector current.
--- Wikipedia on Gain-Bandwidth Product, https://en.wikipedia.org/wiki/Gain–bandwidth_product#Transistors
Consider what you are trying to amplify. You will have an antenna, a signal will arrive to this antenna, it will "excite" electrons and induce a current, which in turn will produce voltage. How much voltage will it produce? A few millivolts? How much gain do you need? Do you need to amplify a few millivolts into volts? Then you need gain of 1000. Is 2N2222 able to provide gain of 1000? No. If I recall correctly its maximum is 300 or so.I have a working FM transmitter on a raspberry pi2. I'm running my FM raido at 103.3MHz, and the antenna that I connected to the GPIO4 is a 20cm copper wire.
More data:(checked with a multimeter between GPIO4 and pin6-ground)
I manually checked the distance by tunning cell phone fm to 103.3MHz. it was around 10 meter.
- DC voltage: 1.2V
- AC voltage: 1.8V
- Current: 18.4mA
which transistor to use to amplify 103.3MHz radio signal?
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by Jake Hertz
by Jake Hertz