Arabsat's Badr spacecraft operate from 26° East, which for much of the region places them fairly high in the southern sky and makes them one of the easier positions to receive reliably.
What makes 26° East interesting from an installation point of view is not the satellite itself. It is how often people want it alongside another position, and the specific ways that arrangement goes wrong.
Two positions, one dish
Because geostationary satellites all sit along a single arc, two positions that are close together in longitude appear close together in the sky. When the angular separation is small enough, one reflector can illuminate two LNBs at once — each aimed at a slightly different point.
There are two ways to do this, and picking the wrong one is a common and frustrating mistake.
A monoblock LNB
A monoblock holds two feeds at a fixed spacing in one housing, with a built-in switch. The receiver selects between them with a DiSEqC command. It is neat and cheap.
The catch is in the word fixed. The spacing is manufactured for one particular angular separation. A monoblock built for one pair of positions cannot be repurposed for a pair that sits further apart — the second feed simply will not be looking where you need it to. Always check the separation the unit is specified for before buying.
Two separate LNBs on a multi-feed bracket
More adjustable, and the right answer when the separation does not match an off-the-shelf monoblock. Each LNB is mounted independently and aimed on its own, then both feed a DiSEqC switch.
The trade-off is that only one LNB sits at the true focus. The other is offset, so it collects slightly less energy. In practice that means the secondary position always has a little less margin than the primary — something to remember when one position holds up in rain and the other does not.
DiSEqC, and the port you forgot to label
Whichever approach you use, a switch is involved, and the receiver selects between positions by sending DiSEqC commands up the same coaxial cable that carries the signal down.
| Version | What it does | Typical capacity |
|---|---|---|
| Tone burst | Simple A/B selection | 2 positions |
| DiSEqC 1.0 | Committed switching between LNBs | Up to 4 positions |
| DiSEqC 1.1 | Uncommitted switching, cascadable | Up to 16 positions |
| DiSEqC 1.2 | Drives a motorised dish to stored positions | Many, by index |
| USALS | Computes positions from your coordinates | Any visible satellite |
For two or three fixed positions you want DiSEqC 1.0. Configuring 1.1 for a small setup simply will not work — it uses a separate command set intended for cascaded switches.
And label the ports physically, on the switch, with a pen. Almost every later problem in a multi-position install traces back to nobody knowing which dish is on which port.
Setting it up in an order that works
- Get one position working alone first. Connect a single LNB straight to the receiver, no switch in the path, and peak it properly. This proves dish, LNB, cable and receiver before any switching logic is introduced.
- Set the LNB oscillator per satellite entry. A universal Ku LNB uses 9750/10600. A wrong value makes every calculated frequency wrong, and the symptom looks exactly like a misaimed dish.
- Add the switch and assign ports one satellite at a time, matching the physical wiring.
- Verify each position separately by locking a transponder you know is live on it.
- Scan last, only once every position locks on its own.
The failures you will actually see
| Symptom | Cause |
|---|---|
| One position works, the other finds nothing | Port assignment does not match the wiring |
| Both positions show identical channels | Both receiver entries pointing at the same port |
| Secondary position weaker in rain | Expected — the offset LNB is not at the true focus |
| Vertical works, horizontal missing | Voltage drop; the LNB never reaches 18 V through the switch |
| Low band fine, high band absent | 22 kHz tone not getting through |
| Intermittent switching | Cable too long or thin for the switch's current draw |
| Only a quarter of expected channels | A quattro LNB wired straight to a receiver instead of a multiswitch |
Notice how many of those are power, not aim. A DiSEqC switch consumes current itself and adds insertion loss, so a cable run that was fine for a directly connected LNB can become marginal once a switch is inserted. The 18 V horizontal state fails first because it demands the most.
Reception basics still apply
Arabsat broadcasts in Ku-band, so the same mechanics govern reception as at any other Ku position. Downlinks across the region sit broadly between 10.7 and 12.75 GHz. The LNB converts that block down to an intermediate frequency the cable can carry, using 9750 MHz for the low band and 10600 MHz for the high band, with a 22 kHz tone selecting between them and 13/18 V selecting polarisation.
Dish size depends on where you sit inside the footprint rather than on the satellite. Near the centre of coverage a modest reflector is ample; toward the edge the same service needs more collecting area. The operator's footprint map, with its coverage contours and suggested diameters, is the authoritative reference — and going one size up from what it says buys the rain margin that a minimum-size install has none of.
Align on signal quality, never strength. Strength largely reflects LNB power and cable condition, and reads healthy while pointed at empty sky.
