Free CSI Practice Questions

Question 1

An installer adds an in-line booster to improve a satellite system's rain reliability. On the same transponder, the receiver input rises from -48 dBm to -20 dBm, while modulation error ratio (MER) falls from 14 dB to 8 dB and the picture begins breaking up. The receiver specifies an input range of -65 to -25 dBm. Reception was clean before the booster was fitted. Which correction addresses the new fault without sacrificing dish alignment?

Accepted Answer

Remove the booster and verify reception on the original signal path.

Answer

Move the dish slightly off its signal peak to bring the input level down.

Answer

Fit a lower-noise LNBF without removing the booster.

Answer

Replace the receiver because the falling MER establishes a defective tuner.

Question 2

During dish acquisition, a meter finds two nearby azimuth peaks. The stronger peak measures -38 dBm but is identified as an adjacent satellite. The other measures -44 dBm and is positively identified as the required satellite. Both readings are within the meter's operating range. Where should the installer perform final peaking?

Accepted Answer

At the identified target satellite, optimizing its demodulated signal quality.

Answer

At the stronger peak, to maximize fade margin.

Answer

Between the two peaks, balancing received power against the requested orbital direction.

Answer

At neither peak until a larger reflector makes the target as strong as its neighbor.

Question 3

The datasheet for a proposed 150-ft coaxial run lists 4.0 dB loss per 100 ft at 500 MHz and 6.0 dB per 100 ft at 1500 MHz. At the 1500-MHz carrier being checked, connectors and the bonding block add 2.0 dB in total. The level entering the run is -48 dBm, and the receiver's minimum is -65 dBm. The installation requires at least 5 dB above that minimum. Considering this signal-level budget alone, which assessment is correct?

Accepted Answer

The receiver gets -59 dBm, leaving 6 dB above its minimum; the requirement is met.

Answer

-56 dBm, with 9 dB of margin; the run meets the requirement.

Answer

-57 dBm, with 8 dB of margin; accept the proposed cable route.

Answer

The receiver gets -61 dBm, leaving only 4 dB above its minimum; reduce the losses before acceptance.

Question 4

As a coaxial connector approaches a satellite receiver's chassis, the installer sees repeated arcing. The customer reports receiving a shock from the connected television earlier that day. No one is currently touching the equipment. What takes priority before any further reception testing?

Accepted Answer

Stop work, keep people clear, safely isolate equipment, and arrange qualified electrical correction.

Answer

Try a shared power strip to eliminate the chassis voltage difference.

Answer

Fit an RF isolator in the coax and resume testing if the arcing no longer occurs.

Answer

Replace the coaxial bonding block, reconnect the equipment, and check whether the picture improves.

Question 5

A conventional two-tuner DVR is connected through a passive splitter to one output of a twin universal LNBF. The LNBF has a second, unused, independently controlled output. Either tuner works alone, but a recording fails when the other tuner selects the opposite linear polarization. The receiver does not support a single-wire channel-stacking system. What will provide independent tuning?

Accepted Answer

Run a second coax from the unused LNBF output to the second tuner.

Answer

Use a splitter with DC pass on both outputs.

Answer

Add a satellite amplifier ahead of the existing splitter.

Answer

Disable LNBF power on one tuner and let the other control the shared feed.

Question 6

After an RV moves several hundred miles, it receives national channels from the correct satellite on both polarizations, but cannot lock the transponder carrying the owner's hometown local channels. The account remains authorized, and the provider confirms that transponder is operating. Its coverage map places the RV inside the national beam but outside the hometown local beam. What explains the difference?

Accepted Answer

The local transponder uses a spot beam that excludes the new location.

Answer

The receiver lacks entitlement to the missing local services.

Answer

The dish is aimed at another satellite carrying similar national services.

Answer

A failed polarization switch prevents reception of the local transponder.

Question 7

A replacement universal linear-Ku LNBF is labeled with a 9.75-GHz low-band oscillator and a 10.60-GHz high-band oscillator. The installer needs to receive a horizontally polarized carrier at 12.45 GHz. Which receiver command and expected intermediate frequency belong together for this carrier?

Accepted Answer

18 V with 22 kHz enabled; an IF of 1850 MHz.

Answer

18 V with the 22-kHz tone off; 2700 MHz IF.

Answer

13 V with the 22-kHz tone on; 1850 MHz at the IF output.

Answer

18 V with the 22-kHz tone on; 2700 MHz at the IF output.

Question 8

A fixed multi-satellite installation must receive all three orbital positions specified for the service. The approved cable design permits runs up to 150 ft at this site. Which proposed location is ready for installation as described, without first resolving another identified site limitation?

Accepted Answer

A pole site with a verified foundation, clear paths to all three positions, and an approved 130-ft cable route.

Answer

A wall site with sound framing and a 60-ft cable route, where an evergreen blocks one required orbital position.

Answer

A nonpenetrating roof site with clear paths and a 70-ft route, where roof-load capacity has not been checked.

Answer

A chimney site with clear paths and a 90-ft route, where loose mortar is visible around the proposed mounting point.

Question 9

For several clear March afternoons, a correctly aligned system loses reception for a few minutes at nearly the same time each day, then recovers without intervention. Nearby subscribers using the same satellite report matching interruptions, and the times coincide with the provider's published solar-interference window. The customer requests a new LNBF. Which response fits the evidence?

Accepted Answer

Explain the temporary sun outage and retain the verified alignment and equipment.

Answer

Replace the LNBF before further use because the afternoon timing indicates thermal failure.

Answer

Repoint the dish to avoid the Sun, then retain the new alignment.

Answer

Fit a higher-gain line amplifier to overcome the interruption.

Question 10

An older television has a working analog antenna tuner but no baseband video inputs. A satellite receiver provides composite video and left/right line-level audio. The customer wants to use the television's existing coaxial lead. Which additional device can turn the receiver's selected program into a channel the television can tune?

Accepted Answer

An analog RF modulator matched to the receiver's A/V outputs and television tuner.

Answer

A satellite/terrestrial diplexer with separate 75-ohm ports.

Answer

A passive 75-ohm RCA-to-coax connector adapter.

Answer

An analog audio/video switch with matching RCA connectors and one output.

Free CSI Practice Questions

Domain 1: Satellite Communications History and Theory

Question 1

Domain 2: Satellite Dish Reflectors

Question 2

Domain 3: Cabling

Question 3

Domain 4: Amplifiers

Question 4

Domain 5: Satellite Dish Feed-horns, LNBs and LNBFs

Question 5

Domain 6: Satellite System Installation - Site Surveys

Question 6

Domain 7: Satellite Receivers - Digital Technology

Question 7

Domain 8: Interfacing With Other Consumer Electronics Equipment

Question 8

Domain 10: Troubleshooting, Repairs, Sun Outage

Question 9

Domain 11: Safety

Question 10

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