How to Check Your DStv Signal Strength

Where to find the signal screen

You do not need any tools to see what your decoder is receiving. Every DStv decoder exposes a diagnostics screen, and on the Explora it is reached from the remote.

Press the DStv button to open the menu, then go to Settings. MultiChoice’s own Explora quick guide lists what sits under that menu: User Preferences, Parental Control, System Settings and Satellite Settings. Satellite Settings is where the dish and signal information lives.

The two numbers, and why only one really matters

This is the part that trips almost everyone up, and getting it the right way round will save you a wasted callout.

Signal strength

Strength tells you how much energy is arriving at the tuner. It largely reflects whether the LNB is powered and the cable is intact. Here is the catch: a cable that is disconnected at the dish end can still show a respectable strength reading, because the tuner is measuring noise along with signal. Strength on its own proves very little.

Signal quality

Quality tells you how much of that energy is actually usable data from the satellite. This is the number that decides whether you get a picture. If quality is low you get pixelation, freezing or an error message, no matter what strength says.

Why digital satellite fails suddenly rather than gradually

Analogue television degraded politely — a weak signal just looked grainy. Digital satellite does not behave that way. The DVB-S2 standard that DStv uses is designed around a threshold: above it, error correction delivers what the standard calls "Quasi Error Free" reception; below it, the picture collapses.

ETSI, the standards body that publishes DVB-S2, defines that target as "less than one uncorrected error-event per transmission hour" for a typical television service. The practical consequence is the cliff edge every installer knows: a marginal installation looks perfect on a clear day and drops out entirely in the first serious weather, because there was never any margin in hand.

Why this guide does not quote you a target percentage

Search for this topic and you will find plenty of South African pages confidently telling you to aim for a specific signal strength and quality percentage. We went looking for the official source of those numbers and could not find one.

MultiChoice’s published Explora and HD decoder guides document the menu, the dish size and the LNB type. They do not publish a numeric target for the on-screen strength and quality readouts, and acceptable values legitimately vary between decoder models and transponders.

Where your dish actually has to point

DStv in South Africa is carried from the orbital slot at 68.5° East. Two satellites are co-located there: Intelsat 20, and Intelsat 36, which was built specifically to carry MultiChoice’s Ku-band direct-to-home payload and launched to join it at the same position.

Because the satellite is geostationary, the direction never changes. From anywhere in South Africa it sits to the north-east, and the angle above the horizon depends on where in the country you are. The further south and west you go, the lower it sits.

Look angles to 68.5°E, calculated from standard geostationary pointing geometry and cross-checked against a published azimuth/elevation calculator. Use them to sanity-check a dish position, not as a substitute for peaking on a meter.

The compass trap almost everyone falls into

This is the single most useful thing on this page, and it is where most do-it-yourself alignment goes wrong.

The azimuth figures above are measured from true north. A magnetic compass — including the one in your phone — points to magnetic north, and in South Africa the difference is large. Magnetic declination across the country runs roughly 20° to 31° west.

Apply that and the numbers change character completely. A Johannesburg dish at 62.6° true is around 83° on a compass: not north-east at all, but very nearly due east. Someone lining a dish up to "north-east" on a phone compass will end up around twenty degrees off the satellite — which, on a signal that has a cliff edge, is the difference between a working installation and a blank screen.

• If you are using a compass or a phone app, use the magnetic column in the table above, not the true azimuth.
• If you are using a satellite-finder app that overlays the satellite on your camera view, it has already handled the declination — trust the overlay, not the raw bearing.
• Either way this only gets you approximately on target. Approximately is exactly the alignment that fails in the first storm.

Can you check DStv signal with your phone?

Partly — and it is worth being precise about what a phone can and cannot do, because a lot of people search for this expecting more than is possible.

What a phone genuinely helps with

A satellite-finder app uses the compass and camera to show you roughly where the satellite sits in the sky. That is genuinely useful for one thing: establishing whether a tree, a wall, a new extension or a neighbour’s roof is sitting in your line of sight. Stand at the dish, point the phone along the path, and you can see immediately whether anything is in the way.

What a phone cannot do

It cannot measure your signal. It has no connection to your dish, your cable or your LNB. It knows where the satellite is; it knows nothing about whether your installation is receiving it. Aligning a dish with an app alone gets you close, and close is not the same as peaked.

Peaking a dish properly means a meter connected to the cable, moving the dish in small increments and watching the reading rather than the sky. That is what puts margin in the system.

Rain fade: why a storm takes your picture away

Losing the picture during a heavy downpour is normal for satellite television, and it has a name: rain fade, or rain attenuation. Raindrops absorb and scatter the microwave signal on its way down, and the effect gets worse as frequency rises. DStv broadcasts in the Ku band, which is squarely in the range where it matters.

This is well-characterised engineering rather than folklore. The International Telecommunication Union publishes the standard prediction method for it, Recommendation ITU-R P.618, used worldwide to design earth-space links.

There is also excellent South African measurement. A study published in the SAIEE Africa Research Journal measured rain attenuation on a 12.6 GHz satellite television link fed from Intelsat 20 at 68.5°E, recorded at the University of KwaZulu-Natal in Durban. The researchers noted that attenuation "becomes especially severe at frequencies of 5 GHz and above", and that beyond about 10.7 dB of attenuation the link was "completely squelched".

The paper also frames the design goal in a way that is useful for householders: links are planned to be available for at least 99.99% of the year, which allows a fade margin corresponding to roughly 87.6 hours of outage annually in the worst case.

Working through low signal quality, in order

Start at the decoder and work outwards, because the cheap causes are also the most common.

1. Check the cable at the decoder. Finger-tight, and the centre pin straight rather than bent or pushed back. Loose F-connectors account for an enormous share of the callouts we attend.
2. Bypass any splitter or extra point. Connect the decoder straight to the main cable temporarily. Splitters and poor joints degrade quality quietly and are easy to rule out.
3. Look at the dish from the ground. You are checking for anything obviously wrong: a dish visibly hanging or rotated, a loosened bracket, cable that has come away from its clips or is chafing, or new growth in the line of sight.
4. Consider the weather and the timing. Heavy rain reduces quality temporarily and it returns. A drop that started after a storm and never recovered is a shifted dish, a water-damaged LNB or damaged cable.
5. Check whether it affects all channels or some. Whole-transponder losses point at alignment or the LNB; a single channel group behaving differently is worth mentioning when you book.

What your dish and LNB should actually be

If you are diagnosing a persistently marginal installation, it is worth confirming the hardware is what MultiChoice actually specifies, because a surprising number of underperforming installs are simply under-specified.

As published in MultiChoice’s own Explora quick guide and HD decoder quick start guide.

MultiChoice is explicit about why this matters. Its Explora guide warns that "if your DStv Explora is installed with any other type of LNB, the installation may require changes to receive future services", and states the underlying principle plainly:

What the LNB actually does

The LNB — low-noise block downconverter — is the device on the arm at the front of the dish. It receives the very low-level microwave signal the dish concentrates on it, amplifies it, and converts it to a much lower frequency band that can travel down ordinary coaxial cable to the decoder. Your decoder controls it down the same cable, using supply voltage and a 22 kHz tone to select polarisation and frequency band.

That is why LNB faults produce such odd symptoms: an LNB failing on one polarisation can take out half your channels while leaving the rest perfect. If that sounds familiar, our guide to the five signs an LNB is failing covers what to look for.

Common mistakes

• Reading strength instead of quality. Strength can look healthy on a completely disconnected dish.
• Using a magnetic bearing as a true bearing. Worth 20–31° of error in South Africa — more than enough to lose the satellite entirely.
• Aligning by watching the on-screen bar. The screen updates with a lag and you cannot see it from the roof. This is how dishes end up peaked on a sidelobe rather than the satellite.
• Assuming rain dropouts mean a faulty installation. Brief loss in a real downpour is expected. Loss in light rain is not.
• Adding splitters to feed extra rooms. Satellite does not split like an aerial signal. Extra viewing points need the right LNB and cabling — see how Extra View actually works.
• Ignoring a slowly worsening reading. Corrosion and water ingress are gradual. A baseline reading taken on a clear day is the only way to notice.

When it is genuinely a technician job

If quality is low or unstable and the connections at the decoder are sound, the fault is almost always at the dish end: alignment, the LNB, or the outdoor cable and its connectors. All three need someone on the roof with a meter, and all three are routine work for someone who does them daily.

What you should expect from that visit is a measured result, not a shrug. We align on a meter, record the final reading and show it to you before we leave, so you have evidence the job was done properly rather than approximately. If the underlying problem is a recurring signal fault or a complete loss of signal, that measurement is also what tells you whether the dish, the LNB or the cable is at fault.