School project - British Science Week

morphy_richards · 2021-02-25T15:01:15.372Z

Hi Manuel,
Thanks for your response. If Othernet EMEA Beam is working by the project week, in your opinion will I be able to build a receiver in time? As far as I can tell there I cant obtain a DC currently.

The emulated version of a DC4 on a raspberry pi is something I could certainly set up quite easily. Could you please point me in the direction of a copy of the web interface?

Thanks again!
44
Steve M7RPH

Tysonpower · 2021-02-25T15:22:45.077Z

Hi Steve,

getting a DC4 Prototype could get complicated because there are only a few Prototypes currently.
But maybe i could send you one of my Spare DC3, it isn’t the newest Interface etc. but it should work to show the receiving side to your students. I also have some Bullseye LNBs here for sale that are good for reception if you don’t have a spare LNB, maybe interesting for QO100 as well

The DC4 Firmware is Open Source (GitHub - Othernet-Project/Dreamcatcher), but it will not work without some Modifications, i will take a look at it and build a Emulated Version, i will let you Know if i got something, shouldn’t be to hard.

73 Manuel DO5TY

morphy_richards · 2021-02-25T15:44:19.215Z

Thanks Manuel! I’m getting really excited now.

I’ll digest the your link on GitHub this evening. I have to admit that I already ordered a Bullseye yesterday because, well why would I not?

Here is a link to something we did back in 2015 in a previous project. This was for the launch of a little micro-controller you may have heard of called the ‘Micro Bit’.
If you could spare us a DC3 that would be really amazing.

Thanks once again,
73
Steve M7RPH

Tysonpower · 2021-02-25T17:19:33.337Z

Just send me a quick mail because of the DC3 to do5ty@darc.de
You can never have enough Bullseye LNBs really

maxboysdad · 2021-02-25T18:00:49.517Z

Hi Steve,

You are welcome to access my dreamcatcher at aeroute.ddns.net and browse through its functions. You could use it as a live demo or take screen shots as you want for your presentation. This is a live Dreamcatcher v.3.05. It is online, but not currently receiving, as we have not yet made contact with the new satellite parameters that are forthcoming.

73, Jerry W0HU

morphy_richards · 2021-02-25T18:09:44.761Z

Done

morphy_richards · 2021-02-25T18:10:20.284Z

Thank you that’s really kind.
I will definitely check this out

kenbarbi · 2021-02-25T21:48:56.209Z

Likewise, Steve, you can look at my on-line Dreamcatcher here outside of Washington, DC. It too, as Jerry’s, is not receiving now until Othernet gets their new stream up… Address is: http://98.204.166.71/ Ken (Annapolis, MD, KC3OYM)

Syed · 2021-02-26T03:49:16.408Z

When exactly do you need this finished by?

If you really wanted to, it’s possible to turn a Pi and rtlsdr into a receiver, but all of the additional RF components won’t be cheap. You’ll need a bias tee to drive the LNB. The bias tee from the V3 dongle only goes to 4.67V. There is 2V of drop out on the LNB and the converter in the LNB doesn’t really like to go below 4.5V (though it will work below that figure).

You’ll also need an additional down converter, since the IF from the LNB will be too high for an rtlsdr. And then you’ll need to demodulate LoRa packets in software. It’s actually all doable, but a ton of work. Probably the easiest thing to do is borrow a Dreamcatcher.

Sgtpepper · 2021-02-26T06:42:21.379Z

Hey Morphy,
I’m in the U.K. and can loan you my kit. Alternatively if the MUX isn’t up the experiment I did with my son to teach him about satellites just included a sat finder and one of those “caravan” dishes (although you could do it with a used Sky one too, there are loads of second hand on eBay very cheap), just running into the Freesat transponder and showing them how to receive a TV broadcast.

morphy_richards · 2021-02-26T10:51:17.564Z

Thanks everyone for all of your input. I will keep you all posted in this thread as things progress.
73 Steve M7RPH

Tysonpower · 2021-02-27T14:19:10.226Z

Just as quick info, a DC 3.05 i had laying around is on it’s way to Steve

morphy_richards · 2021-03-12T14:46:35.419Z

Hi all,
DC 3.05 has arrived!
Science week has coincided with students returning to school from lockdown so rather than this being part of a short “flash-in-the-pan” project week it will now be incorporated into a longer running STEM initiative. It will be a few short weeks until things settle down and we work out the logistics of running after school clubs that are compatible with year group ‘bubbles’.

I will have fun this weekend learning about the DC 3.05 and Bullseye LMB.
73 M7RPH

mw1mdh · 2021-03-13T21:02:28.951Z

Be interested to hear how you get on!

73 de MW1MDH!

morphy_richards · 2021-03-18T08:50:30.729Z

Hi everyone,
Thanks all of you for your interest, communities like this one which are genuinely friendly, helpful and enthused are rare on the internet.
Sadly, after school clubs now need to be managed more strictly and with less time available due to the ongoing effects of the pandemic.
Nevertheless we are planning to run our first session on Tuesday 27th April for an hour. There can be additional sessions on subsequent weeks. The Maths department has also offered to run sessions to support the maths we cover.

In that one hour session I think it would be good to cover the background, ie. effects of the information divide and some of the efforts that are being made to counter it, obviously focusing on Othernet but not limiting it. (There is also Elon Musk’s Skynet(?), Google’s project Loon

The students can then get hands on aligning the LNB and fine tuning the DC…

I have to go but will add more later.

Syed · 2021-03-18T17:20:57.751Z

The SpaceX Starlink internet service will be a major disruptive force in the satellite communications industry. It will also impact terrestrial ISPs in rural areas.

Google Loon recently shutdown.
https://www.google.com/amp/s/qz.com/africa/1961328/why-googles-loon-internet-balloon-project-crash-landed/amp/

morphy_richards · 2021-03-19T12:45:29.423Z

That’s good, I can use all of this…

morphy_richards · 2021-03-19T12:46:22.518Z

Can you point me to anything about disruption from spaces please?

morphy_richards · 2021-03-19T12:53:42.128Z

20210319_1243384608×3456 2.41 MB

20210319_1243294608×3456 2.19 MB

This is the setup I am going to try to go with… That’s an old microphone stand from the old, now defunct media studies dept.

I need to find a good way to visually show the angle of inclination and declination of the arm with the LNB.

Could just use a satellite finder app but there’s something to be said for doing it in the old fashioned way to link it to the equipment the students use in class … (thoughtful face emoji)

Syed · 2021-03-19T13:02:23.195Z

Don’t forget skew adjustment. That can be a talking point for linear and circular polarization of radio waves.