Cover Image
close this bookRadio and Electronics (DED Philippinen, 66 p.)
close this folder3. TRANSDUCERS
View the document(introduction...)
View the document3.1. MICROPHONES
View the document3.2. LOUDSPEAKERS
View the document3.3. THE TELEPHON SYSTEM
View the document3.5. BANDWIDTH


As we already could see during the experiment described above, we can produce a much wider range of frequencies than the range we can listen to. Our ears are able to receive soundwaves within special limits, the range of audible (hearable) waves is called also a BANDWIDTH. We can say our ears have a bandwidth of 50 to 20000 Hz. We will come across these terms several times while dealing with radiotechnology.

fig. 17

The graph shown in fig 17. explains again what a bandwidth is, and it shows too how different the bandwidths are for different sophisticated communicationsystems. Keep in mind: Even though the bandwidth of a telephon system is very narrow in comparison with bandwidth of the audio frequencies we are able to understand the partner at the other end of the communication line.


1. What is the meaning of the term COMMUNICATION actually?

2. What is the difference between a telephon and a radio system?

3. How are the devices called which are translating sound waves into electric signals?

4. How are the four different types of microphones functioning?

5. Which different types of loudspeakers do You know?

6. What is the meaning of the terms “fidelity” and “distortion”?

7. What is the meaning of the terms “Spectrum” and “bandwidth”?

8. Applying your knowledge of Ohms Law try to describe how the circuit shown in fig. 16 manages to produce the