8-E-40: Transmission Lines
8-40E1:
The VSWR of a microwave transmission line device might be measured using:
A dual directional coupler, a power meter, and a network analyzer.
A dual directional coupler and a power meter.
A network analyzer.
A spectrum analyzer.
8-40E2:
The impedance total (ZO) of a transmission line can be calculated by ZO = √L/C when L and C are known. When a section of transmission line contains 250 microhenries of L and 1000 picofarads of C, its impedance total (ZO) will be:
500 ohms.
50 ohms.
250 ohms.
1,000 ohms.
8-40E3:
If long-length transmission lines are not properly shielded and terminated:
Communications receiver interference might result.
The silicon crystals can be damaged.
Overmodulation might result.
Minimal RF loss can result.
8-40E4:
A certain length of transmission line has a characteristic impedance of 72 ohms. If the line is cut at its center, each half of the transmission line will have a ZO of:
72 ohms.
36 ohms.
144 ohms.
The exact length must be known to determine ZO.
8-40E5:
Standing waves on a transmission line may be an indication that:
Some of the energy is not absorbed by the load.
All energy is being delivered to the load.
Source and surge impedances are equal to ZO and ZL.
The line is terminated in impedance equal to ZO.
8-40E6:
What precautions should be taken with horizontal waveguide runs?
They should be sloped slightly downwards at the elbow and a small drain hole drilled in the elbow.
They should be absolutely level.
They should not exceed 10 feet in length.
None of the above.
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