Over on her YouTube channel, SignalsEverywhere, Sarah has uploaded a new video showing how she uses a PlutoSDR, HackRF and mixer to transmit DVB-S digital amateur TV to a standard satellite set top box. In this video the idea is to get a little more range by using the PlutoSDR to transmit in the 70cm band, then upconverting that to the 23cm band right at the satellite receiver. Transmitting at the lower frequency yields a higher power output from the PlutoSDR and less cable loss. The mixer consists of a passive mixer chip and a HackRF is used as the mixer LO signal source as a temporary test solution.
Daniel Estévez has posted on the LimeSDR Mini CrowdSupply blog about his ground-station build for the Es'Hail-2 satellite. Es'Hail-2 is the first geostationary satellite with amateur radio transponders on board. The LimeSDR Mini is a $159 RX/TX capable SDR with 10 MHz to 3.5 GHz frequency range.
The Es'Hail-2 satellite is positioned at 25.5°E which is over Africa. It's reception footprint covers Africa, Europe, the Middle East, India, eastern Brazil and the west half of Russia/Asia. There are two amateur transponders on the satellite. One is a narrow band linear transponder which uplinks from 2400.050 - 2400.300 MHz and downlinks from 10489.550 - 10489.800 MHz. Another is a wide band digital transponder for digital amateur TV (DATV) which uplinks from 2401.500 - 2409.500 MHz and downlinks from 10491.000 - 10499.000 MHz.
Daniel's ground station uses a LimeSDR Mini running on a Beaglebone Black. A 2.4 GHz WiFi parabolic grid antenna is used to transmit to the satellites digital amateur TV uplink. In order to generate enough power for the uplink transmission a GALI-84 amplifier chip is cascaded with a 100W power amplifier. All the electronics are enclosed in a watertight box and placed outside.
Over on YouTube Tech Minds has posted a video explaining what Es'hail-2 satellite is and why it is interesting for hams and SDR users. Briefly Es'hail-2 is a recently launched geostationary TV satellite that covers Africa, Europe, the Middle East, India, eastern Brazil and the west half of Russia/Asia.
What's special about it is that apart from the TV transmitters, it also contains the worlds first amateur radio transponder in geostationary orbit. So amateur radio users within the region covered by the satellite can simply point their antennas to a fixed position in the sky to transmit to the satellite, and the signal will be rebroadcast over the entire covered area. With a simple LNB, satellite dish and SDR the signals can be received.
After explaining Es'hail-2 Tech Minds also shows a demo of Es'hail-2 radio traffic using a public WebSDR.
Es'hail 2 was launched last November and it is the first geostationary satellite to contain an amateur radio transponder. The satellite is positioned at 25.5°E which is over Africa. It's reception footprint covers Africa, Europe, the Middle East, India, eastern Brazil and the west half of Russia/Asia. There are two amateur transponders on the satellite. One is a narrow band linear transponder which uplinks from 2400.050 - 2400.300 MHz and downlinks from 10489.550 - 10489.800 MHz. Another is a wide band digital transponder for amateur digital TV which uplinks from 2401.500 - 2409.500 MHz and downlinks from 10491.000 - 10499.000 MHz.
Although it launched last year it takes several months for the engineers to test and qualify the transponder for use. Over the last few weeks the transponder was intermittently active during the testing, but now since Feb 13 2019 the amateur transponder has finally been fully activated for amateur radio use.
To receive it with an RTL-SDR or most other SDRs an LNB is required to receive the 10 GHz signal and downconvert it into a frequency range that most SDRs support. Typically an Octagon LNB is used, and these are easy to find and cheap as they are often used for satellite TV.
From various reports seen on Twitter, it seems that the signal is strong enough that a satellite dish is not required for receiving - simply pointing the LNB directly at the satellite is enough.
If you can't set up a receiver, there is an OpenWebRX livestream of the Es'hail 2 narrowband channel that has been set up by Zoltan/RFSparkling which is available at sniffing.ddns.net:8073 (note the server can only handle 8 users at a time, so try again later if it's busy). Also as pointed out by KD9IXX on Twitter, there are also several websdr.org servers receiving and streaming Es'hail2 including an Airspy based one run officially by AMSAT-DL.
Over on YouTube Corrosive from channel SignalsEverywhere has uploaded a new video in his series on Digital Amateur Television (DATV). The new video shows us how to use a transmit capable SDR like a LimeSDR or PlutoSDR to transmit DATV with a free Windows program called DATV Express.
In the video he explains the various transmit and video encoding settings, and then demonstrates the signal being received on SDRAngel with an RTL-SDR (which he explained in his previous video)
Es'hail 2 was launched last November and it is the first geostationary satellite to contain an amateur radio transponder. The satellite is positioned at 25.5°E which is over Africa. It's reception footprint covers Africa, Europe, the Middle East, India, eastern Brazil and the west half of Russia/Asia.
Although the satellite was launched last year, turning on the amateur transponders has been slow because the commercial systems of the satellite have higher priority for testing and commissioning. However, within the last day the Es'hail 2 team have now begin testing the amateur transponder, and the test signal has been successfully received by several enthusiasts (just check out the Twitter feed). There also appears to have already been a suspected pirate CW signal broadcasting "WELCOME DE ES2HAIL". Actual uplink use of the satellite is not currently wanted, and from the Amsat forums one of the engineers writes:
Before the IOT starts there will be a TRR (test readyness review) in front of the customer. All the testplans and test-specifications will be reviewed. When the test is done there will be a TRB (test readyness board). In the TRB they have to show/present all the measurement results (e.g. inband performance like Gainflatness, Groupdelay... aso.) and compare these results with the specification in the contract. Each unwanted signal makes the measurement difficult and needs to be explained or leads to a so named NCR (non conformance report).
The IOT will be done in shifts/nightshifts and with unwanted signals (if not explain able) some measurements needs to start again and again and leads in addition to a delay for the handover and operation of the satellite.
Maybe that helps to understand why it is really important to have only the IOT uplink signal.
To measure the pattern of each antenna the satellite will be moved east/west by the propulsion system of the DS2000 Bus and the signal level is measured by the IOT station on ground (some cuts) .
The commercial beacon can maybe be switched from LEOP Omni antenna to on station antenna when the satellite is placed in the final slot. This should be the reason for the change of the commercial Ku Band beacon signal level the last days.
If you are interested in receiving Es'hail 2, but live outside the footprint, or don't have a receiver then you can use Zoltan's OpenwebRX live stream of the narrow band portion of the Es'hail 2 downlink. At the moment the beacon doesn't appear to be transmitting, but we expect it to be on and off during the next few days. In his set up he uses an RTL-SDR V3, Inverto LNB, 90cm dish, a DIY bias tee and a Raspberry Pi 3.
He also took a recording of the pirates CW transmission shown in the video below.
Over on YouTube Corrosive has uploaded a new tutorial video showing us how we can demodulate DVB-S DATV (Digital Amateur TV) on a Windows PC with SDRAngel. DATV is a mode used by hams to transmit and receive digital video, and SDRAngel is a multiplatform SDR software platform that supports multiple SDRs such as the RTL-SDR, HackRF, PlutoSDR, LimeSDR and more.
SDRAngel comes with a built in DATV demodulator, but it is necessary to install the FFMPEG video decoder yourself. Corrosive's tutorial shows where to download the decoder, and how to install it into SDRAngel. He then goes on to show how to use SDRAngel to begin receiving and demodulating a DATV signal.
We note that in a previous post Corrosive also showed in another video how to transmit and receive DATV with a LimeSDR and a modified $20 DVB-S receiver.
Today SpaceX have successfully launched and deployed the Es'hail-2 satellite which is now in geostationary orbit. This launch is special for amateur radio enthusiasts because it is the first geostationary satellite that contains an amateur radio transponder on it. The satellite is positioned at 25.5°E which is over Africa. It will cover Africa, Europe, the Middle East, India, eastern Brazil and the west half of Russia/Asia. Unfortunately, North America, Japan, most of South America, Australia and NZ miss out.
The satellite has a two bandwidth segments, a 250 kHz narrow band for modes like SSB, FreeDV, CW, RTTY etc, and a 8 MHz wide band for digital amateur TV (DATV) modes like DVB-S and DVB-T.
The downlink frequencies are at 10 GHz so a low cost TV LNB could be used as the antenna. For receiving the narrowband modes, an RTL-SDR or similar SDR could be used, and for the 8 MHz DATV modes a standard DVB-S2 set top box can be used to receive and decode the video. For uplink, the transmission frequency is at 2.4 GHz.
According to the commissioning order of the satellite, it is expected that the AMSAT transponders will be activated only after all tests have been passed, and after other higher priority commercial telecommunications systems have been activated. This is expected to take about 1-2 months.