|
![]() |
|||||||||||||||||||
![]() |
|
|||||||||||||||||||
|
|||||
|
Chapter 6 – Antennas
Antennas are the key to radio — without them, signals are not transmitted or received. Amateurs enjoy building and experimenting with antennas and you will, too! Section 6 covers this important section in detail.
Antennas
Transmission Lines
Table 6-1 Feedline Characteristics
The table printed in the 1st printing of the General Class License Manual is in error. The following table contains the correct typical loss data for several popular types of coaxial cable. Cable loss and other parameters such as velocity of propagation vary between manufacturers and sometimes from batch to batch. If you are using the cable in a way that depends on an exact value, measure the cable with test equipment. The values in the table below were calculated using the on-line calculator at Times-Microwave ().
Type |
Impedance (ohms) |
Loss per 100 feet (in dB) at 30 MHz |
Loss per 100 feet (in dB) at 150 MHz |
RG8 |
50 |
1.08 |
2.53 |
RG8X |
50 |
1.96 |
4.53 |
RG58 |
50 |
2.47 |
5.63 |
RG59 |
75 |
1.79 |
4.11 |
RG174 |
50 |
4.56 |
10.3 |
RG213 |
50 |
1.08 |
2.53 |
9913 |
50 |
0.68 |
1.58 |