Why Your DStv Cuts Out When It Rains (and What Actually Helps)
3 min readAustin Installation
By Austin Installation · Updated September 2026 · Cape Town
Your DStv signal drops or pixelates every time it rains hard. You are not imagining it, and it is not because something is broken. Rain fade is a real physical limitation of satellite TV. But there is a difference between normal rain fade (which every satellite system experiences) and a poorly installed system that gives up in a drizzle. Here is how to tell the difference and what you can actually do about it.
What rain fade is and why it happens
DStv uses the IS-20 satellite at 68.5 degrees east, broadcasting in the Ku-band frequency range (10.7 to 12.75 GHz). Water absorbs and scatters these frequencies. When heavy rain sits between your dish and the satellite, the signal weakens or drops entirely.
This is physics, not a fault. No dish size, no cable quality, no installer skill level eliminates rain fade completely. What good equipment and good installation do is raise your baseline signal strength so high that only the heaviest downpours cause a dropout. A poorly installed system drops out in moderate rain. A well-installed one holds through everything except a genuine Cape Town thunderstorm.
Normal rain fade vs a problem
| Symptom | Likely cause |
|---|---|
| Signal drops only during heavy thunderstorms (10+ minutes of hard rain) | Normal rain fade. Every satellite system does this. Signal returns within minutes of the rain easing. |
| Signal drops in moderate rain or drizzle | Your baseline signal is too low. Dish misalignment, undersized dish, corroded connectors or a faulty LNB. |
| Signal drops in light rain and takes 20+ minutes to return after rain stops | The dish has shifted, the cable has water ingress, or the LNB is failing. This needs a technician. |
| Signal pixelates but never fully drops | Marginal signal strength. A realignment or larger dish would fix this. |
What you can do about it
1. Check your signal strength numbers
On your decoder, go to Settings, Satellite Settings, Signal Strength (the exact path varies by decoder model). You want:
- Signal Strength: above 80%
- Signal Quality: above 75%
If either number is below those thresholds on a clear day, your system is underperforming and rain will push it over the edge. A professional realignment with a satellite meter typically brings both numbers into the 85 to 95% range.
2. Upgrade to a 90cm dish
The minimum spec for DStv is an 80cm dish. A 90cm dish has about 25% more surface area, which means 25% more signal collected. The cost difference is R100 to R200 for the dish plus R200 to R400 for the swap labour. For Cape Town properties that experience regular rain fade, this is the single most effective upgrade. It will not eliminate rain fade in a downpour, but it will keep you watching through the moderate rain that currently drops your signal.
3. Check and replace connectors
The F-connectors where the coaxial cable meets the LNB (on the dish) and the decoder are the most common point of failure. Coastal properties corrode these connectors within 1 to 2 years. Corroded connectors leak signal even in dry weather and collapse entirely when wet. Replacing connectors is a R50 to R100 job in parts. If you are comfortable on a ladder, you can do it yourself with a coaxial cable stripper and compression F-connectors from any electronics shop.
4. Waterproof exposed connections
The LNB connection at the dish is exposed to the elements. Self-amalgamating tape (also called vulcanising tape) wrapped around the F-connector and LNB body creates a waterproof seal. This costs R30 to R50 for a roll and takes two minutes. If your installer did not do this, it is the cheapest upgrade you can make.
5. Clear obstructions
Trees grow. A branch that was not in the signal path two years ago might be now. Even partial leaf coverage weakens signal enough that rain pushes it over the edge. Check the line of sight from your dish to the satellite (roughly north-east from Cape Town). Trim anything in the way.
What will NOT help
- Pointing the dish "more north": the satellite is at a fixed position. Moving the dish away from that position makes things worse, not better.
- Adding a signal booster: boosters amplify noise as well as signal. On a satellite system they rarely help and often hurt. If your signal is weak, fixing the cause (alignment, LNB, connectors) is better than amplifying the symptom.
- Switching to a bigger LNB: LNB quality matters, but LNB size does not. A larger LNB does not collect more signal. That is the dish's job.
Cape Town rain fade: the seasonal pattern
Cape Town gets most of its rain between May and September (the winter rainfall season). If your system was installed in summer and seemed fine, and then started dropping out in winter, the rain is probably the cause. But do not assume it is just seasonal. A system that cannot hold through moderate winter rain is a system that was marginal to begin with. Get the signal numbers checked before you spend another winter watching a pixelated screen.
Coastal suburbs (Sea Point, Camps Bay, Bloubergstrand, Hout Bay, Fish Hoek) get additional wind-driven rain that inland suburbs do not. The combination of salt corrosion weakening connectors and heavier rainfall events means coastal installations need annual maintenance to stay reliable.
When to call a technician
If your signal drops in anything less than heavy rain, or if your signal strength numbers are below 80% on a clear day, a technician with a satellite meter can realign your dish, replace corroded connectors, test the LNB and bring your system back to spec. Most realignment jobs take under an hour and cost R300 to R500. We service all of Cape Town. See our DStv service page or call us directly.
Call 067 706 5216