SBCA System Troubleshooting & Maintenance 2

Question 1

A satellite receiver shows a signal strength of 85% but signal quality drops to 20% during rain. What is the most likely cause?

Accepted Answer

Rain fade causing signal attenuation on Ku-band frequencies

Answer

Rain fade is a well-known phenomenon where precipitation absorbs and scatters Ku-band signals, reducing signal quality even when the carrier is detected.

Question 2

When performing a spectrum analyzer sweep on a satellite transponder, you observe a raised noise floor across the entire bandwidth. What does this typically indicate?

Accepted Answer

Uplink interference or transponder overload from excess carrier power

Answer

A raised noise floor across a full transponder typically indicates uplink interference or an overdriven transponder from excess carrier power.

Question 3

A VSAT terminal suddenly loses two-way communication but can still receive broadcast channels. Which component is most likely faulty?

Accepted Answer

The transmit BUC (Block Upconverter)

Answer

Since receive functionality is intact, the transmit BUC is the most likely failed component preventing two-way communication.

Question 4

What does a C/N (Carrier-to-Noise) ratio measurement indicate in satellite link analysis?

Accepted Answer

The ratio of carrier power to thermal noise power in the receiver bandwidth

Answer

C/N ratio expresses how much stronger the desired carrier signal is compared to the thermal noise floor, directly impacting demodulation performance.

Question 5

During routine maintenance, a technician finds the dish elevation has drifted 2 degrees below the optimal setting. What is the most likely cause on a fixed mount?

Accepted Answer

Thermal expansion and contraction cycles loosening mount bolts

Answer

Thermal cycling causes metal mounting hardware to expand and contract, gradually loosening bolts and allowing dish position to drift.

(SBCA) Satellite Broadcasting and Communications Association Certification Practice Test

(SBCA) Satellite Broadcasting and Communications Association Certification Practice Test

SBCA System Troubleshooting & Maintenance 2