numbers tech related Flashcards
According to the C/N rule, each time the number of amplifiers doubles, the C/N gets worse by how much?
3 dB
Per FCC rules, signal leakage between 54 MHz and 216 MHz must not exceed what?
20 microvolts per meter at 3 meters
What is the typical bandwidth for C-band service?
500 MHz
What frequency range must a spectrum analyzer have in order to align satellite dishes?
950 MHz - 1450 MHz
All drop splitters must have a minimum return bandwidth of?
5 MHz to 42 MHz
What is the diameter, in microns, of a single mode fiber strand with the coating intact?
250 microns
“Four Nines” or 99.99% reliability allows for how many downtime minutes per customer per year? +/- 1 min.
52.42
What is the proper depth of modulation percentage of the properly balanced video carrier?
87.5
What is the maximum length of a series-6 drop that can be used in an underground installation?
150 feet
What is the maximum current output supported by the Vista 20P control panel?
600 mA
What is the maximum length for a coax jumper used between a wall plate and the CPE?
6 feet
When terminating an unused tap port, what must be included in the terminator?
Internal 75-ohm resistor
Per FCC rules, signal leakage between 54 Mhz and 216 Mhz must not exceed what?
20 microvolts per meter at 3 meters
What is the reference temperature to determine thermal noise level delivered to any load impedance?
68 degrees Fahrenheit (293.15 degrees Kelvin)
When making attachments to the strand, what is the minimum distance from the center of the pole that the attachment can be made?
30 inches
What is the minimum cable bend radius for series 6?
2.5 inch radius
What CLI figure of merit must be met in order to comply with Federal Communications Commission Standards?
For each dB increase in input optical power (dBm), the RF output increases by how many dBmV?
2 dBmV
How much bandwidth is required when both video and audio broadcasts are sent via a satellite in analog format?
36 MHz
What is 1 per million as expressed in scientific notation?
1.0E-6
What is 1 millivolt equal to across a 75 ohm load?
0 dBmV
What is the typical 1550nm fiber loss in dB/km?
0.25(+/-.1dB)
When purchasing a fractional PRI, what is the minimum number of channels required per account?
6
What is the total bandwidth, to the nearest thousandth, required for a single 24-channel PRI circuit?
1.544 Mbps
What resistance is present in a circuit where 1 ampere of current dissipates 1 watt of power?
1 ohm
What is the FCC signal leakage limit for frequencies below 54 MHz and above 216 MHz?
15 microvolts/meter at 30 meters (100 feet)
What frequency does Comcast use for the MoCA channel?
1,150 MHz or 1.15 GHz
What is the minimum PHY rate required between the Media Hub and the terminal?
180 Mbps
When is the use of Series-11 or QR-320 permissible for an aerial drop?
Greater than 150 feet or in situations where it will improve signal levels to within acceptable ranges
What is the acceptable minimum tightening force for the connector on the port of a splitter?
20 inch lbs.
What is the value for Boltzmann’s Constant?
1.38x10E-23
What is the maximum number of lines supported by a Polycom 335?
2
What size ground wire is used with series-11 and QR320 cables?
10BRIS 7.1.7
How many splices are permitted in an underground drop restoration with a cable longer than 60 feet which does NOT cross a driveway?
2
To reduce the possibility of bleeding, carrier power levels of adjacent channels should be kept within what distance of each other?
Within 2 dB of each other
In a typical off-hook state, what is the level of tip wire voltage?
-20VDC
Which log value is used to calculate carrier to noise?
10