Satellite TV signal loss at night at certain frequencies can be attributed to a phenomenon known as “ionospheric scintillation” or “nighttime ionospheric disturbances”. Earth’s ionosphere, a region of Earth’s upper atmosphere, plays an important role in reflecting and refracting radio waves, including those used for satellite communications.
Here are some reasons that can cause problems with satellite signals at night:

Ionospheric changes:

During the day, the ionosphere is often more stable, allowing for the best satellite signal transmission. However, at night, some ionospheric layers change due to decreased solar radiation. This can cause some variation in signal power, especially at certain frequencies.

Ionospheric scintillation –

Ionospheric scintillation refers to rapid variations in signal amplitude and phase caused by irregularities in the ionosphere. This phenomenon occurs more often at night and can cause signals to disappear on some frequencies.

D-Layer Absorption –

The D-layer of the ionosphere, which is responsible for absorbing some radio frequencies, becomes more apparent at night. This absorption can result in signal attenuation or loss, especially at those DTH frequencies that are sensitive to D-layer absorption.

Low satellite elevation angle –

The elevation angle of the satellite relative to your location can affect the signal’s path through the atmosphere. At night, when the satellite is close to the horizon, the signal can pass through a larger portion of the atmosphere, increasing the incidence of ionospheric interference.

Solar Minimum Impact –

Solar activity varies in approximately an 11-year cycle, with periods of high and low solar activity. During solar minimum (low activity), ionospheric conditions can be more unpredictable and sensitive to disturbances.

Frequency-Dependent Effects –

Different frequencies exhibit different levels of sensitivity to ionospheric disturbances. Lower frequencies may experience greater absorption, while higher frequencies may be more prone to scintillation.

To mitigate these issues, satellite communications systems often use frequency diversity, error correction techniques, and adaptive modulation to adapt to changing ionospheric conditions. If you are experiencing persistent signal loss at night,

So consider checking your DTH connection as follows:

Set the satellite dish properly –

You should make sure that your satellite dish is set correctly from satellite to satellite.

Breakage of cable and connector –

Check your cables and connectors for any damage.

If there is no problem mentioned above then you should make some changes such as –

Antenna size and type –

Depending on your location and the satellite’s Ku-Band signal, using a larger or different type of antenna may improve signal reception.

Size and type of LNB –

You should replace your LNB, and buy a branded LNB. Try not to use local or unbranded cheap DTH LNB.

If the problem persists, you may need to contact a professional technician to fix your problem.

FAQs, Satellite TV