Tektronix 2715, Руководство пользователя

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2715 User Manual
B–1
Appendix B: Broadcast AM, FM, and TV Signal Sources
CAUTION. To prevent damage when connecting signal sources to the 2715, be
certain the total signal strength is less than +70 dBmV. If in doubt, check with a
broadband RF wattmeter or voltmeter.
For some of the experiments in this manual, you need AM or FM modulated
signals. The most readily available signals are AM and FM broadcasts. To
receive AM or FM broadcast radio stations, you can plug a piece of wire directly
into the center terminal of the input connector and hang the other end out a
nearby window. If your building is not metal-framed, you can probably use a
length of wire that fits within the same room as the spectrum analyzer. The
required length of wire will depend on the strength, location, and frequency of
the transmitter, among other variables; 50 kW FM stations 40 miles distant have
been received with a wire paper clip, straightened and inserted directly into the
input connector.
CAUTION.
The spectrum analyzer can be damaged by static discharge or
high-level signals. Remove any static charge before connecting a wire or
antenna to the spectrum analyzer.
Remove any static charge by first momentarily grounding the wire to the case of
the instrument. If the wire may be carrying AC or DC power, measure it with a
high-impedance voltmeter or oscilloscope to be sure that it does not exceed the
DC input rating of the spectrum analyzer. If you are close to a transmitter, be
sure to set a reasonably high value of RF attenuation before connecting the wire
or antenna to the spectrum analyzer. Use the spectrum analyzer to measure the
signal amplitude at the frequency of the transmitter before going to lower
attenuator settings. If you have an accessible antenna (such as a wire or whip)
connected, ground yourself to the case of the instrument to dissipate body static
charge before touching the antenna.