Flashcards in nct 4 signals Deck (91)
The Cable TV System is also referred to what type of a system?
A Closed Loop System.
Within what part of the coaxial cable is the radioenergy is designed to be contained within?
The spot of damaged cable where the radio energy escapes into free space, transmitting (egress) and receiving (ingress) signals becomes what?
When a leakage is discovered, how do we isolate and locate the cause, make repairs, and verify that the leakage has been resolved?
By using radio receivers tuned to the aeronautical frequency band.
What must every system do to verify that there is no ingress above the power levels specified by the FCC?
Complete a proof of performance test and submit itsreport to the FCC periodically
What is the difference between a microvolt and a millivolt?
A Microvolt is unit of electric potential equal to one millionth (10-6) of a volt. A Millivolt (mV) is a unit of potential difference equal to one thousandth (10-3) of a volt.
Is the exponent or the power to which a fixed number (the base) must be raised in order to produce a given number.
How are Logarithms normally computed?
To the base of 10 and can therefore be defined as ‘The exponent of 10 required to equal the number.’
What is the log of 100?
The log of 100 is 2 (10 with an exponent of 2 = 100.)
What are Logs (logarithms) used for?
Is used for shortening mathematical calculations.
What’s an Exponent?
Is the number of times the base is multiplied by itself. (Example: 10 to the 2nd power = 100, 2 is the exponent)
What is a Base?
The number being raised. (Ex: 10 to the 2nd Power = 100, 10 is the base).
Any number raised to the exponent 0 is equal to what?
Any number raised to the exponent 1 is equal to what?
How does one multiply two or more numbers with the same base?
By adding the exponents.
How does one divide two or more numbers with the same base?
By subtracting the exponents.
What Prefix is a 10 with an exponent of 9?
What Prefix is a 10 with an exponent of 6?
What Prefix is a 10 with an exponent of 3?
What Prefix is a 10 with an exponent of -3?
What Prefix is a 10 with an exponent of -6?
What Prefix is a 10 with an exponent of -9?
What Prefix is a 10 with an exponent of -12?
if 256 QAM is employed the baud rate is how many bits per second?
Definition of Hertz
the System Of Units (SI) unit of frequency, equal to one cycle per second.
What is a continuous signal or carrier that varies in amplitude or frequency as a function of changes at its input?
An analog signal.
A non-continuous signal or carrier that changes its output in discreetly timed steps of voltage level and/or phase that can represent numerical values or other information.
Name 4 of the 8 advantages that digital transmission has over analog transmission:
1) No noise or distortion accumulation.2) High immunity to interference.3) Error checking may be included.4) Can be compressed and/or encoded.5) Easily stored and retrieved.6) Can be multiplexed and multi-layered.7) Unlimited copying or regeneration.8) Little or no loss of quality over long distances.
2 of the 3 disadvantages of digital transmission are:
1) Some loss of quality may occur in the conversion process.2) Added expense of digital processing devices.3) Digital terminal.