Makers eXperimenters and Operators

Thursday, 7 March 2019

Es'hailsat 2 decoding using just a funcube dongle and your existing sky dish feed

@amsatdl #amsat #Eshail2 just a sdr plugged into existing sky dish not moved just standard. Proof of concept @AmsatUK @amsat @qo100_sat pic.twitter.com/DEWfVZYG9M
— Arow Antena (@arrowantenna) March 7, 2019

I installed sdrsharp on my laptop, tuned to around 739MHz.
I took one of the existing sky tv connections from the back of the sky box and gently inserted the core and held the edge of the connector to that of the funcube or airspy dongle for best (temporary) connection.

You can clearly see the signal is floating up and down, it's not stable, but you can easily understand and track the qso.

For those wanting to just have a quick go as proof of concept, this requires little to no skill or additional equipment. any sdr dongle will do. The better you can get the connector attached to the dongle the better the signal!

The 739 MHz is what the LNB Local oscillator creates and should be your starting point on the sdr frequency, you will need to tune up and down and find the top and bottom beacons.

Tuesday, 5 March 2019

ISS School contact with Ceip Nuestra Señora Del Carmen, Torre De La Reina, Spain on March 5 at 09:50 UTC

My audio copy of ISS-Astro David St-Jacques OR4ISS talking to Ceip Nuestra Senora Del Carmen, Torre De La Reina, Spain via EG7NSC heard on 8-deg pass over Staines IO91SK at 09:50 UTC

You can hear my recording here with just a white stick X-50 antenna

slightly longer example much better set up from Dave Boult take a listen here

An International Space Station school contact has been planned with participants at Ceip Nuestra Señora Del Carmen, Torre De La Reina, Spain on 05 Mar. The event is scheduled to begin at approximately 09:50 UTC. The duration of the contact is approximately 9 minutes and 30 seconds. The contact will be direct between OR4ISS and EG7NSC. The contact should be audible over Spain and adjacent areas. Interested parties are invited to listen in on the 145.80 MHz downlink. The contact is expected to be conducted in English.

Torre de la Reina is located south of the main population center of Guillena (Sevilla) about 2 kilometers from it and is about 19 meters above sea level. It is also just 17 kilometers from Seville capital if you take the direction to the south on the A-431 road, also enjoying a strategic location privileged to be located very close to the A-66 (Autovía de la Plata) that connects Sevilla capital with Extremadura. Our school is located in the town of Torre de la Reina, (Seville, Spain), with 215 students, including children and primary school. It has two buildings, one of the infantile stage (recent construction) and another one of primary (something older). The staff consists of 15 teachers. We are a small center, but with a young staff, willing to invest in experiences of all kinds that enrich our students.There are many activities that we carry out within different projects, with the aim not only of fulfilling the educational curriculum, but also of developing competences to train integral people. Also one of our hallmarks of identity is to form values and an emotional education, because we consider that it is fundamental in the education of today's society.The heart and the vocation to educate is our engine every day. The resources we have are not many, but the human side compensates for any technical and material aspect.

Participants will ask as many of the following questions as time allows:

1. What did you think when you saw Earth from space?
2. What are you currently investigating on the ISS?
3. When did you decide to become an astronaut?
4. How do you live in such a small place?
5. How long do you need to recover after finishing your missions?
6. If an astronaut floats away from the ISS, what do you have to do?
7. Which values and skills should an astronaut have?
8. Can you eat whatever you want?
9. What´s the most common problem inside the ISS?
10. Could you go to Mars with this ISS?
11. Can you have a shower or bath there?
12. Where do you throw your rubbish?
13. How long can you stay at the ISS?
14. Is there a doctor in the ISS?
15. How many hours do you sleep every day?
16. How do you keep fit?
17. What´s your favourite food and drink there?
18. Do you listen to music at work?
19. Can you see our country from the ISS?
20. When will you come back to Earth?

Monday, 4 March 2019

notes on satellite LNB (eshailsat 2, qo-100) information as I learn and try to understand it

Universal LNB’s work by the receiver selecting one quarter of the channels at any one time. It does this by alternating the voltage between 13V and 18V which will enable the LNB to switch between Horizontal and vertically polarised signals. A 22kHz tone then switches the LNB from a low and high band. Hence a quarter of the channels at any one time. Vertical Low, vertical high, horizontal low, horizontal high.

Satellite signals are beamed down from the satellites in space to the satellite dish at a frequency which is far too great to be contained by the coaxial cable. At this point the signals are oscillated to fall down to a frequency band – Satellite intermediate frequency (IF) which sits just above the UHF band used for terrestrial TV and 4G internet signals and has a bandwidth of around half of that which was previously available before being oscillated. So the universal LNB will oscillate one half of the frequency band at a great rate than the other half, hence the high and low band.

Ku-Band, which is divided in a low band from 10.7GHz to 11.7GHz (Lo: 9.75 GHz) and a high band from 11.7GHz to 12.75GHz

on eshailsat 2 we are looking at a receive frequency of 10489690 MHz take away the Local Oscillator (LO of 9.75GHz) gives us 739Mhz. 739 is where we point our SDR or receiver.

GNURADIO can be used on hackrf etc as an ssb transmitter using blocks created by DL9SW
https://www.qrz.com/lookup/DL9SW

Phaselocking to Es’Hailsat-2 / QO-100’s upper PSK400 beacon

raspberry pi 2 sdr cat control to a 817-nd
SAT CONTROLLER SDR NANO

Fow the wideband TV stuff you can start reading on here, looks like to just get the beacon (wide signal) you change the crystal in the lnb and tune your sky box. more later when I have time to test
https://wiki.batc.org.uk/Receiving_Oscar_100_DATV_signals

narrow band RX LNB can be bought cheaply from here:
https://www.amazon.co.uk/Goobay-67321-Universal-Single-LNB-grey-white/dp/B00DO49CVC/ref=dp_ob_title_ce

Bias-t
https://www.sotabeams.co.uk/blog/biast-for-lnb-a-few-notes/

Bias-t schematic