Es'hail-2 Ground Station
The BATC & AMSAT-UK QO-100 (Es'hail-2) WebSDR & Spectrum Monitor are located at the iconic Goonhilly Earth Station in Cornwall (IO70JB).
Using the Wideband spectrum monitor and Narrow band SDR
Wideband monitor
The Wideband Spectrum Monitor can be accessed at https://eshail.batc.org.uk/wb/
To log in, type the following in to the box at the bottom of the chat (replacing "my name" with your real name or callsign) and press return:
/nick my name
For example:
/nick G8ABC_Fred
You will get a confirmation message that your name has changed and the text in the box changes to "Type a message here and press enter" - your name also appears in the list on the right handside of the page.
Narrow band SDR
The Narrowband WebSDR can be accessed at https://eshail.batc.org.uk/nb/
This user guide written for the Farnham websdr gives a detailed description on how to use the web sdr http://farnham-sdr.com/WebSDR-User-Guide.pdf
The chat facility is actually an dedicated IRC channel and to access it, enter your name or callsign in the "nickname" box, tick "I am not a robot and press "connect"
Details of the installation
The equipment is housed in a room dedicated to amateur radio infrastructure in the workshops building for the now defunct GHY2 90 ft dish antennae, built in 1969.
As well as the Es'hail-2 (now known as Qatar Oscar 100) WebSDR and spectrum monitor, the station houses an AMSAT-UK Funcube ground station and an HF Kiwi WebSDR with GPS TDOA.
RF System
Dish
The original dish installed in August 2018 was a consumer model and suffered damage in strong winds during October 2018.
This was replaced in January 2019 with a heavy duty Hirschmann 1.3m offset dish.
RF Front End
A modified Octagon quad LNB is mounted on the dish and locked to the 25 MHz output from a Leo Bodnar GPSDO.
See https://wiki.batc.org.uk/Es%27hail-2_LNBs_and_Antennaes for more details on the locking modifications
The 25 MHz reference is fed to the LNB through a dedicated coax run, and 2 further coax runs are used to feed separate horizontal & vertical feeds back to the equipment room.
Receivers
2 separate AirSpy USB SDR Receivers, locked to a 10MHz output from the LeoBodnar GPSDO, are used for the WebSDR and Spectrum monitor.
GPS reference
The GPS reference is a Leo Bodnar unit, running firmware version 1.12, programmed to produced 10 MHz (for the Airspys) and 25 MHz for the LNB. The settings for the reference to produce these 2 frequencies were not straightforward (as the 2 outputs on the Leo Bodnar unit need to be linked) but are here for reference:
Computer System
Hardware
The WebSDR & Spectrum Monitor both run off a single machine with the following hardware specification:
- Intel i7-2600 CPU
- 16GB DDR3 RAM
- Intel DQ67SW Motherboard
- 500GB Samsung 850 EVO SSD
Software
- Ubuntu Server 18.04
- Nginx Web Server & Reverse Proxy (github-webpages)
- Narrowband resampler 2.5MS -> 512Ks (github)
- Narrowband WebSDR by PA3FWM (homepage, github-configuration)
- Wideband Transponder FFT Spectrum Server (github)
- Chat Server (github)
Networking
Goonhilly Earth Station has 2x diverse redundant 10Gb links into JANET PoPs. They have been kind enough to give us a dedicated IP address and access to >300Mb/s of up & down bandwidth for use by the station.
A pfsense firewall running on a PC Engines APU2D4 board is used as the station router & firewall.
A high-bandwidth Leo Bodnar NTP Server provides NTP service to the station & the worldwide NTP Pool. Stats and graphs of this service can be viewed at https://eshail.batc.org.uk/ntp/