Es'Hail 2

 

 

 


 

 

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Introduction

The Es'Hail 2 satellite was launched in November 2018 and supports the first geostationary ham radio transponder. On this page you see:

  • Enabling display of frequencies > 9 GHz,
  • How to configure SDR Console with either the Lime or Pluto SDR,
  • Using the telemetry beacon to compensate for drift / offset due to a poor consumer LNB,

Future development may include digital voice, images, text using Opus as the codec and up to 32 QPSK carriers in a 2.5 kHz bandwidth (we have the bandwidth, let's use it). Opus is an outstanding codec with excellent compression.

My Station

Here's a link to G4ELI's station - still being assembled.

  • Antenna
  • LNB
  • SDR transceiver
  • GPDO
  • Gallery

 

In Action

Here's the Es'Hail 2 footprint. Use the Satellite option in SDR Console to display:

  • Footprint,
  • Azimuth, Elevation,
  • Distance,
  • Path loss.

There is a very small amount of Doppler, even for a geostationary satellite, but not enough to worry about. Here you see the footprint.

    

 


 

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Console Configuration

Follow these steps to successfully configure the console to receive with any SDR and for transmit either a SDR (Pluto, LimeSDR) or an external radio with an up-converter.

  • Enable display of frequencies greater than 9.999 GHz,
  • Create a RX/TX converter definition,
    • Up to 3.0.15: Add a down-converter definition and a TX offset
    • 3.0.16 and above: Add a RX/TX converter definition
  • Enable RX/TX frequency and mode synchronisation.
  • External Radio:
    • 3.0.17 and above: If you are using an external radio + up-converter for transmit add an up-converter entry to your external radio configuration.
  • Optionally use the telemetry beacon to compensate for drift / offset due to a poor consumer LNB.

 

Display > 9.999 GHz

To display a frequency greater than 9.999 GHz open the Program Options and navigate to Display, Spectrum. Select a frequency range of 99.9 GHz, then press [OK].

 

3.0.16 Converter Definition

Note: In version 3.0.16 the old converter definition + TX offset has been replaced with a RX/TX converter with full transceiver support, a big improvement over previous versions.


In the Radio Definitions window check Converter selection, then press Edit.

In the Converter Definitions window click the QO-100 link (top center) to automatically enter the common settings for a QO-100 down-converter. The receive downconverter is 9,750.225 MHz, the transmit is 8089.5 MHz.

Press Apply to add this definition.

 

3.0.17 External Radio

In 3.0.17 and above you can synchronise SDR Console with an external radio used for transmit. The External Radio page is here [link].

 

In the External Radio options [?] select Up-Converter:

 

Enable this option if the external radio is connected to a transmit up-converter or must transmit on a different frequency to the displayed RX frequency, for example when using a VHF/UHF radio + 2.4GHz up-converter with QO-100:

  • Radio: TS-2000
    Frequency range (IF) 144 ... 146 MHz or 432 ... 434 MHz
  • Up-converter
    Frequency range (RF) 2400 ... 2402 MHz

The up-converter offset is the difference between:

  • SDR Console RX frequency, and
  • Displayed external radio frequency (not the transmit up-converter frequency).

Remember - the external radio is synchronised with the RX frequency.

Example 1: If the RX frequency is 10489.70 MHz and the displayed external radio frequency is 144.70 MHz then the up-converter frequency is:

10489.70 -     (RX Frequency)
  144.70       (External radio)
--------
10345.00 MHz

So you enter 10345.000.000 as the up-converter offset.

Example 2: If the RX frequency is 10489.60 MHz and the displayed external radio frequency is 432.60 MHz then the up-converter frequency is:

10489.60 -     (RX Frequency)
  432.60       (External radio)
--------
10057.00 MHz

So you enter 10057.000.000 as the up-converter offset.

 


 

Transponder Band Plan

The narrow band transponder details are show below.

  Low High Note
Receive 10489.55 10489.8 Bandwidth = 250kHz
Transmit 2400.05 2400.3  
CW Beacon 10489.55    
Telemetry   10489.8  

 

Synchronise

In the Transmit DSP enable Sync RX so the receive and transmit frequencies are the same.

 

3.0.15 Converter Definition

For versions of SDR Console up to and including 3.0.15 you define a receive down-converter and a TX offset.

Receive Down-converter

Define a down-converter offset for the LNB (a LNB is a downconverter), the offset is the LNB's local oscillator frequency, for example 9,750MHz. This value is selected when starting the SDR.

In the Radio Definitions window check Converter selection, then press Edit.

 

In the converter definitions window add a down-converter using the LO frequency of your LNB. Usually this is 9.75 GHz but it's quite common for a LNB's oscillator to vary, for example the Octagon LNB in use at G4ELI has a frequency of 9.750190 GHz (190 kHz higher than 9.75 GHz), so in the window below you would enter 9.750.190.000 .

Ideally the frequency you enter results in the Es'Hail 2 beacons being within 10kHz of their nominal frequency as this makes the beacon locking easier.

The BATC has an interesting page on their Wiki Es'hail-2 LNBs and Antennas.

 

Now start the SDR, selecting the new down-converter definition.

 

Transmit Offset

If you use a SDR for transmit (Pluto, LimeSDR) then add an offset. Note: this option is replaced in 3.0.16 with a RX/TX converter definition.

From the transmit options, add an offset which is then added to the displayed transmit frequency. For Es'hail 2 this offset is 8089.5 MHz.

 

Telemetry Beacon

(Available in 3.0.7) Enable the Geostationary Beacon option: Ribbon Bar, View, More Options..., check [X] Geostationary beacon.

Note: the idea for synchronising with the telemetry beacon comes from Moe Wheatley (AE4JY) in his AO-40 Telemetry Decoder Project. Moe's code explains how the data beacon works as the QO-100 beacon is the same as that in AO-40 (RIP). The implementation here was coded from the the ground up to ensure it is as efficient as possible, every saved cycle helps!

The telemetry beacon frequency is 10.489.800.000 Hz, or 10,489.800 MHz. The beacon transmits BPSK, simple BPSK decoding software can determine the offset from the nominal center frequency, so compensation for an un-modified consumer LNB is possible.

Follow these steps:

  • Start the display - press 
  • Select the beacon by clicking in the center of the beacon trace, the window on the left will sdisplay the offset, use  and  to adjust the waterfall zoom level
  • Enable offset compensation - press 

Use the Save 💾 option to download the offset data to a CSV file, this file can be viewed with programs such as Excel.

 

Beacon Frequency

October 10th, 2019: In version 3.0.15 the beacon frequency is user-selectable should the frequency change in the future. An option button ••• has been added to the display, this displays the options window below where the beacon frequency is selected.