EXERCISE 7 Answer the questions about the text

1. What units can be called the main units of a multichannel system?

2. Which elements are used in frequency converters?

3. Which other elements, beside non-linear are enabled in communication apparatuses? What is their advantage?

4. Why do radio engineers need frequency converters?

5. What is changed with the help of the frequency converters?

6. What elements does the circuit of a FC (frequency converter) consist of?

7. What types of FC can you name?

1. 
   Apparatuses on ______and thin-route systems with frequency division of channels and amplitude modulation are comprised into different_____.
   
2. 
   Main units of a multichannel system are ______, amplifiers, generators, electric filters and several special units – differential systems, _______, amplitude limiters, range extenders and range compressors, _______ and correction circuits.
   
3. 
   There are also used frequency converters with ______ which help to obtain greater signal amplification.
   
4. 
   Frequency converters are used ______ frequency spectrum from one area into another.
   
5. 
   In this process the frequency _______ is not broken, only _______ is changed at the output of the converter.
   
6. 
   The structural circuit consists of a converting element, ______ and filter.
   
7. 
   One can find the following types of converters: _____ (with one converting element), ______ (two elements), and _____ (4 elements).
   
8. 
   Most SHF receivers use ______ as converting element.
   
9. 
   Transistor converters use _____ transistor or ______ transistor as converting element.