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QO-100 calculator

QO-100 is the first amateur radio transponder in geostationary orbit, on the Es'hail-2 satellite at 25.9°E. Point your dish at it, and convert between the 2.4 GHz uplink, the 10 GHz downlink and your LNB's IF.

Frequency converter

9750 for a standard universal LNB
Receiver tunes to (IF)––
Where in the transponder––
ItemUplink (MHz)Downlink (MHz)

Dish pointing for QO-100

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From your device
To check trees or buildings
Azimuth––
Compass bearing––
Elevation––
LNB skew––
Clearance––
Distance––

Where to look

The centre is straight up and the edge the horizon. The dashed arc is the belt of geostationary satellites as seen from your location.

Other satellites from here

SatelliteAzimuthElevationSkew

UK postcodes are looked up with postcodes.io, and US ZIP codes and Australian postcodes with Zippopotam.us. They aren't stored. Results are for a standard offset or prime-focus dish, pointed at the satellite's position.

What QO-100 is

Es'hail-2 is a Qatari communications satellite launched in 2018 at 25.9°E, and it carries two amateur transponders, operated as QO-100 by AMSAT-DL and Es'hailSat. Because it's geostationary, it's always in the same place in the sky and available 24 hours a day to stations from Brazil to Thailand, including all of Europe, Africa and the Middle East. The narrowband transponder carries SSB, CW and data, like a giant HF band that's always open. The wideband transponder carries digital amateur TV.

Narrowband: downlink = uplink + 8,089.5 MHz
Wideband: downlink = uplink + 8,089.5 MHz
IF = downlink − LNB local oscillator

Receiving

Reception needs only a 60 to 90 cm dish, a standard universal satellite LNB and an SDR. The LNB converts the 10.489 GHz downlink down to about 739 MHz with its standard 9.75 GHz oscillator, which any cheap SDR can tune. Standard LNBs drift by tens of kHz as they warm up, so many people lock theirs to a stable reference, or use the beacons to correct the drift automatically. The beacons are also the easiest way to find the satellite: point the dish, tune to the beacon and peak the signal.

Transmitting

The uplink is in the 2.4 GHz band, a few watts into a 60 to 90 cm dish with a helix or patch feed. You need an amateur licence that permits operation in the 2.4 GHz satellite allocation; in the UK that's available to all licence levels within your licence's power limit. Listen on the downlink to your own signal, keep it no stronger than the beacon, and use the band plan. Many stations use one dish with a dual-band feed for both directions.

Questions

What is the QO-100 downlink frequency?

The narrowband transponder downlink is 10489.500 to 10490.000 MHz, and the wideband 10491 to 10499 MHz.

What is the QO-100 uplink frequency?

Narrowband 2400.000 to 2400.500 MHz, wideband 2401.5 to 2409.5 MHz. The downlink is 8,089.5 MHz higher.

What IF does a 9750 MHz LNB give for QO-100?

About 739.5 to 740.0 MHz for the narrowband transponder.

Where do I point my dish for QO-100 from the UK?

At about 145° to 150° true, 24° to 27° elevation from England, depending on where you are. Enter your locator above for exact figures.