Page 48 - Build Your Own Transistor Radios a Hobbyists Guide to High-Performance and Low-Powered Radio Circuits
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FIGURE 3-12Inductors.
Other types of inductors may come in unfamiliar shapes, such as the examples
shown in Figure 3-13.
FIGURE 3-13 Other inductors/coils.
For the inductor in this figure, on the left side the value says "221," which really
means 22 plus 1 zero following the 22, for 220 IJH. The inductor on the right has
three sets of numbers, but the only one that seems to make sense is "330." But
does this mean that the inductance value is 33 plus 0 zero after 33, for 33 IJH, or
does it mean that the value is literally 330 IJH? The measured value is 330 JjH.
Therefore, in the case of inductors and capacitors, it is always advisable to measure
the component first to make sure (e.g., with an inductance meter for coils and a
capacitance meter for capacitors).
For small-value capacitors (5 pF to 4,700 pF), generally, ceramic disk or silver mica
types are used. For stability and accuracy, though, silver mica capacitors are
preferred (Figure 3-14).
Ceramic Disk Mica
FIGURE 3-14 Small-value capacitors.
Film (e.g., polyester or Mylar) capacitors are also used (Figure 3-15).
