My Radio Telescope Project

[Asur1984]

So, I have been interested in learning more about radio astronomy for a while and do tend to read up on it quite a bit. A good friend of mine knows all about this and when he got an upgraded Sky dish asked if he was able to keep the old one, he then gave it to me to look into using it for my hobby and also, maybe, the degree I am starting through open university later in the year.

So I now have a Sky dish, I plan to look at building this into a radio telescope so I can learn more about this field and also try to get some pretty impressive stuff also.

I am completely starting from scratch on this, so my first port of call is to trawl through this part of the forum for more information on what I am looking for to help me with the build and also to spend time trawling through the tinterweb for more ideas.

I have no electronical experience other than rewiring a plug and making basic circuits in school (many moons ago now) but I am hoping to do this all completely myself by learning some new skills to go along with it.

My budget is very small so am going to be sourcing bits and pieces bit by bit, I know full well that this will take me a good while to eventually put together but I'm looking at this as a continuous project that I am hoping to build and improve upon long after it is (hopefully) up and running, collecting data etc.

My first order of business (apart from putting together a list of parts needed) is to begin clearing the space I will hopefully use in the side garden, this will be a mammoth task in itself as I am in Manchester and the weather doesn't tend to allow for many days use of an electric strimmer (and the nettles in that part of the garden look very angry to me).

So I welcome any suggestions on where to look for more info, as I said, I am already trawling through this forum looking for bits of help that have already been given to others and I do intend to slowly update this thread with progress made, things learned and even little bits of excitement as I slowly tick off the list of parts needed.

 

Thanks for reading and wish me luck

Jon.

 

 

[SteveNickolls]

Hi Jon,

I can't help you in any way except to offer encouragement in your project which sounds very, very interesting. I'm sure you will get help from a knowledgeable SGL member or two soon. Do post how you get on :-)

Best Regards,
Steve

[Asur1984]

Hi Steve, I will be doing. Hopefully going to be putting updates on here as and when I have new bits of kit etc, it will take me a while though, I know that the basics of what I need are not massively expensive but I am working with very limited funds at the minute so I am viewing this as an ongoing project. Even when I have it up and running properly I am going to be looking at tweaking bits here or there and upgrading bits or even just adding to it. As I say, at the minute I have an old dish and the tinterweb to start me off so just putting the list together of basic bits and parts I nee to at least get me started first, the rest will follow.

Jon. 

[Asur1984]

So, my first port of call then is to clear space in the garden to get an idea of where my eventual set up will go. I am lucky to have a front garden (although I do believe that will need my attention first of all) and then I also have quite a large side garden (which is where I was hoping I could set it up). The pictures below are of the side garden and shows the size of the job I am going to be undertaking  I am going to be dismantling the trampoline so that will free up space in the near corner, but my question is, I have a large protected tree just outside of my property line, will this effect the signals I will be looking to pick up? I will be trawling through information later to try and find out, but in the mean time, if anyone has any experience or knowledge of it that would be very helpful. I have found some old concrete flags in the front garden that are not being used so I when it is all cleared I am going to be using them to create a base for the equipment to sit on top of so it is steady and level.

Thanks

Jon.

 

[vlaiv]

I'm a bit interested in doing something similar - making my own radio telescope of sorts. Have no knowledge on the subject, well almost no knowledge, I do know general concepts, and have a few ideas.

My idea was to use a dish, frequency scanner of sorts, so I can tune on particular frequency, and record signal intensity. Have no idea what is available in terms of frequency scanners, and how it would be controlled from computer but I think that ADC should be doable reasonably easy. There is also need for some sort of tracking/scanning mount. So my idea was to use dish on a mount that I could control via computer, also select frequency via computer and do real time sampling of intensity at certain position / frequency. If I could get all of that then it would be easy (for me at least since I'm computer programmer) to develop software to fiddle around with this data. For example pictures of night sky in radio wavelengths would be doable. Time recordings of variable events would be doable (for example time dependence of signal strength in radio bands from a certain source). Not yet sure what kind of phenomena would be interesting to record and analyze - would need to study that subject a bit.

So I wish you good luck with your project and I'll sure keep my eye on your progress!

[Asur1984]

5 hours ago, vlaiv said:

I'm a bit interested in doing something similar - making my own radio telescope of sorts. Have no knowledge on the subject, well almost no knowledge, I do know general concepts, and have a few ideas.

My idea was to use a dish, frequency scanner of sorts, so I can tune on particular frequency, and record signal intensity. Have no idea what is available in terms of frequency scanners, and how it would be controlled from computer but I think that ADC should be doable reasonably easy. There is also need for some sort of tracking/scanning mount. So my idea was to use dish on a mount that I could control via computer, also select frequency via computer and do real time sampling of intensity at certain position / frequency. If I could get all of that then it would be easy (for me at least since I'm computer programmer) to develop software to fiddle around with this data. For example pictures of night sky in radio wavelengths would be doable. Time recordings of variable events would be doable (for example time dependence of signal strength in radio bands from a certain source). Not yet sure what kind of phenomena would be interesting to record and analyze - would need to study that subject a bit.

So I wish you good luck with your project and I'll sure keep my eye on your progress!

I am literally starting from scratch, I have no idea whatsoever. All I am doing is running through various websites to get all the information I need to get this project up and running.

There seems to be lots of programs (free and not so free) out there that can transform the sound received into visual. Ideally I would like to build on the eventual set up and develop something truly amazing, until then just something that works I would be happy with

Jon.

[Asur1984]

Ok, so while I am too far from payday to actually start buying anything as yet, I have been digging around and it pretty much seems that everyone uses Radio SkyPipe. So I have now installed this and am still doing a lot of digging around to see what the best ways of building this are but I think I have a plan now for a very basic set up and then will look to build from there.

Jon.

[Asur1984]

I have been looking at satellite finders for my project, they seem to vary from around £5-£10 right up to over £100. Thought I'd ask what the differences are while I stalk the tinterweb looking for the answers in the mean time.

Thanks all, Jon.

[wxsatuser]

I presume you may have seen this, if not have a look.

http://www.britastro.org/radio/beginning.html

[Asur1984]

4 hours ago, wxsatuser said:

I presume you may have seen this, if not have a look.

http://www.britastro.org/radio/beginning.html

Hi,

Yeah I've seen that one. The setup I'm initially going for though is going to be more based on this:

http://www.aoc.nrao.edu/epo/teachers/ittybitty/procedure.html

Thanks

[Asur1984]

Ok, so it's been a while since my last update.

 

There isn't much to update on as yet though, a few extra bills have come up (and a second hand telescope that I couldn't resist for £30) leading me to not have the spare cash for the build.

In the mean time I'm still working on getting everything else prepped and figuring out how to make everything work.

[Carl Reade]

On 26/07/2016 at 20:29, Asur1984 said:

I have been looking at satellite finders for my project, they seem to vary from around £5-£10 right up to over £100. Thought I'd ask what the differences are while I stalk the tinterweb looking for the answers in the mean time.

Thanks all, Jon.

Hi the more expensive finders will have a lot more features. They will identify which satellite you are pointing at which is very useful as a cm either way will put you on the wrong one. They will also probably be able to read the quality of the signal which is very important for fine tuning the TV signal both useless features for RA. For you project you don't need these features. You may not be able to do the mods you need to do with the more expensive ones. The best to use is the £5:00 analogue meter type they work great and easy to convert as all you need is a strength reading.

Hopefully useful

Carl

[Asur1984]

On ‎29‎/‎08‎/‎2016 at 09:47, Carl Reade said:

Hi the more expensive finders will have a lot more features. They will identify which satellite you are pointing at which is very useful as a cm either way will put you on the wrong one. They will also probably be able to read the quality of the signal which is very important for fine tuning the TV signal both useless features for RA. For you project you don't need these features. You may not be able to do the mods you need to do with the more expensive ones. The best to use is the £5:00 analogue meter type they work great and easy to convert as all you need is a strength reading.

Hopefully useful

Carl

Hi,

Thanks for the heads up

It's the first time I've ever heard "cheaper is better" and I'm certainly not complaining at that!!

Thanks again, Jon

[SteveBz]

Hello Guys,

I stumbled on this by chance.  I started building a radio telescope at the beginning of the summer.  I was in the local Telescope shop (Telescope House) and they thought I'd need a 5m dish to do anything serious.

So carefully heeding their advice I got a used 1.3m satelite dish for a fiver on ebay. You can see it in my profile picture.

Another fiver got me a satelite finder but the most expensive part was the batteries, nearly another tenner.

Within an afternoon I was picking up the sun.  I'll post my results later.

I've been distracted with other things recently, but I hope to do a bit more when the kids go back to school and the rain holds off.

I've been using the shadow of the lnb to direct it, but directing at night is more problematic.

Let me know how you're all getting on.

Regards

Steve.

[Asur1984]

6 hours ago, SteveBz said:

Hello Guys,

I stumbled on this by chance.  I started building a radio telescope at the beginning of the summer.  I was in the local Telescope shop (Telescope House) and they thought I'd need a 5m dish to do anything serious.

So carefully heeding their advice I got a used 1.3m satelite dish for a fiver on ebay. You can see it in my profile picture.

Another fiver got me a satelite finder but the most expensive part was the batteries, nearly another tenner.

Within an afternoon I was picking up the sun.  I'll post my results later.

I've been distracted with other things recently, but I hope to do a bit more when the kids go back to school and the rain holds off.

I've been using the shadow of the lnb to direct it, but directing at night is more problematic.

Let me know how you're all getting on.

Regards

Steve.

Hi Steve,

I would be extremely interested to see what results you are getting, and also to know what programs ect you are using to visualise these (if you are at this stage).

I am currently looking into the possibility of using Raspberry Pi to interface with mine (when it's eventually set up) and maybe learn to write my own program to use also.

Hoping to have a basic version of mine up and running by the end of the month, it's my 32nd birthday then so going to treat myself to hopefully the rest of the gear needed to get up and running.

Thanks ,

Jon

 

[SteveBz]

15 hours ago, Asur1984 said:

Hi Steve,

I would be extremely interested to see what results you are getting, and also to know what programs ect you are using to visualise these (if you are at this stage).

I am currently looking into the possibility of using Raspberry Pi to interface with mine (when it's eventually set up) and maybe learn to write my own program to use also.

Hoping to have a basic version of mine up and running by the end of the month, it's my 32nd birthday then so going to treat myself to hopefully the rest of the gear needed to get up and running.

Thanks ,

Jon

 

My output is a digital voltmeter attached by crocodile clips to the satelite finder.  I take the readings manually but I could use the usb interface from the meter to my pc.

The finder is a total energy meter, but if I want to follow the 21cm line, which I do, then clearly I'll need to get a 1.4GHz filter and amplifier.

I don't know if you've done the sums, but resolution = wavelength over diameter (in radians) for a single antenna.  That's about 10 degrees for my dish. To get better resolution I'd need an array of dishes. 16 dishes spread over 100mx100m would be like a 100m dish. Ie bigger than Jodrell Bank and at less than the cost of my Newtonian (apart from the field to put them in, obviously!).

4 dishes in a straight line would be easier and cheaper, but only give one dimension.

The other approach to building an array would be to cooperate with others ....

I'll write up some of my results here when the kids have gone back to school.

Regards

Steve.

[SteveBz]

On 26/07/2016 at 16:29, Asur1984 said:

I have been looking at satellite finders for my project, they seem to vary from around £5-£10 right up to over £100. Thought I'd ask what the differences are while I stalk the tinterweb looking for the answers in the mean time.

Thanks all, Jon.

Hi Jon,

Almost any finder will do.  Cheaper the better.  The only thing which is very helpful is a loudspeaker.  As I mentioned, mine cost a fiver like this one here:

http://www.ebay.co.uk/itm/Analog-Satellite-Signal-Finder-Strength-Meter-LCD-Display-for-Sat-Dish-DIRECTV-/131452097102?hash=item1e9b27d24e

Here is a more deluxe one for £12.  Worth considering as I had to lay out for additional connectors and stuff, here:

http://www.ebay.co.uk/itm/361468620720?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Here is a video of Mike Brown, renowned Caltech professor and discover of the Ninth Planet and 36 other trans-Neptunian objects talking about using his satellite dish as a radio telescope.  It's not as detailed as some other blogs, but in my view, better written and more motivating.

http://www.mikebrownsplanets.com/2013/06/summer-project-build-radio-telescope-at.html

Good luck,

Steve.

[Asur1984]

6 hours ago, SteveBz said:

Hi Jon,

Almost any finder will do.  Cheaper the better.  The only thing which is very helpful is a loudspeaker.  As I mentioned, mine cost a fiver like this one here:

http://www.ebay.co.uk/itm/Analog-Satellite-Signal-Finder-Strength-Meter-LCD-Display-for-Sat-Dish-DIRECTV-/131452097102?hash=item1e9b27d24e

Here is a more deluxe one for £12.  Worth considering as I had to lay out for additional connectors and stuff, here:

http://www.ebay.co.uk/itm/361468620720?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Here is a video of Mike Brown, renowned Caltech professor and discover of the Ninth Planet and 36 other trans-Neptunian objects talking about using his satellite dish as a radio telescope.  It's not as detailed as some other blogs, but in my view, better written and more motivating.

http://www.mikebrownsplanets.com/2013/06/summer-project-build-radio-telescope-at.html

Good luck,

Steve.

Hi Steve,

Thanks for the links, certainly gives me something to think about.

I'll have a good read of the Mike Brown link too and hopefully I'll pick up some good ideas for my own small set up. I may look to increase the capacity a but further down the line myself but I don't have too much space to play about with but hopefully I can get something decent on the go.

Thanks,

Jon

 

 

[The Admiral]

A somewhat wild idea, perhaps a bit tongue-in-cheek, but I wonder if it'd be possible to use the trampoline frame as the basis for a mini-Arecibo? That annular suspension system would be good to allow a parabolic reflector to form under its own weight. You'd then need to construct a frame above it to hold the antenna/head amplifier.

Ian

[Asur1984]

1 hour ago, The Admiral said:

A somewhat wild idea, perhaps a bit tongue-in-cheek, but I wonder if it'd be possible to use the trampoline frame as the basis for a mini-Arecibo? That annular suspension system would be good to allow a parabolic reflector to form under its own weight. You'd then need to construct a frame above it to hold the antenna/head amplifier.

Ian

Hi Ian,

That actually sounds like a good idea, I was just planning on getting rid of it but now that you mention it, I might try to construct something using that as a base.

My expertise (if you can call it that) lies mainly in woodwork, but, having that to play about with I could look to develop a new skill in metal work too.

See, radio-astronomy, the gift that keeps on giving

Thanks,

Jon

[The Admiral]

Hi Jon,

I'm glad that an off-the-wall thought hasn't met with total derision! I'd imagine that a wooden suspension for the antenna/head amp might be better than a metal one anyway, in that there would be little interaction with the incoming em waves.

The question remains, what would be a suitable 'dish' material? Something heavy enough to form a smooth bowl when held at the edges, and ideally conducting (though I guess it could be covered in aluminium foil). If I understand correctly it doesn't have to be solid so long as any holes are a lot smaller than the wavelength you are trying to reflect (like in your original satellite dish). More strictly I suppose the shape will be a catenary rather than a true paraboloid.

Good luck, and if you really do go down that route, please keep us posted.

Ian

[Asur1984]

26 minutes ago, The Admiral said:

Hi Jon,

I'm glad that an off-the-wall thought hasn't met with total derision! I'd imagine that a wooden suspension for the antenna/head amp might be better than a metal one anyway, in that there would be little interaction with the incoming em waves.

The question remains, what would be a suitable 'dish' material? Something heavy enough to form a smooth bowl when held at the edges, and ideally conducting (though I guess it could be covered in aluminium foil). If I understand correctly it doesn't have to be solid so long as any holes are a lot smaller than the wavelength you are trying to reflect (like in your original satellite dish). More strictly I suppose the shape will be a catenary rather than a true paraboloid.

Good luck, and if you really do go down that route, please keep us posted.

Ian

Hi Ian,

What I think I will do is to take the trampoline apart and store the metal base for a while, that way I can research more into that option.

I will have to look at the different materials that I could use and also the ways to make it work for me, would certainly make for a bigger bit of kit than my old sky dish.

Thanks for the inspiration for a further project

Jon

[SteveBz]

Here are some measurements (figure 4) I took with a digital multimeter (not shown) attached to the Satellite Finder (figure 2) with crocodile clips in early August (only now got round to analysing them).  One of the problems was backgound noise.  There was a guy drilling near me and every time he drilled, the meter jumped, so I had to time my measurements for when he wasn't drilling.  The measurements along the bottom is the position of the shadow on the circular lines I have drawn on the the dish (see figures 1 & 3).

Figure 1, Satellite Dish.

Figure 2, Satellite finder and power supply.

 

Figure 3, Angular distance.

Figure 4, Results.

As you see, the resolution is quite coarse, but I thought I might improve it by using the rather rusty RA motor drive that came with it.  The other way would be to do a driftscan, neither of which I have done yet.

Any ideas welcome.

Regards

Steve.

 

 

 

 

 

video_radio_2016_06_13_trans_crop.mp4

[Asur1984]

5 hours ago, SteveBz said:

Here are some measurements (figure 4) I took with a digital multimeter (not shown) attached to the Satellite Finder (figure 2) with crocodile clips in early August (only now got round to analysing them).  One of the problems was backgound noise.  There was a guy drilling near me and every time he drilled, the meter jumped, so I had to time my measurements for when he wasn't drilling.  The measurements along the bottom is the position of the shadow on the circular lines I have drawn on the the dish (see figures 1 & 3).

Figure 1, Satellite Dish.

Figure 2, Satellite finder and power supply.

 

Figure 3, Angular distance.

Figure 4, Results.

As you see, the resolution is quite coarse, but I thought I might improve it by using the rather rusty RA motor drive that came with it.  The other way would be to do a driftscan, neither of which I have done yet.

Any ideas welcome.

Regards

Steve.

 

 

 

 

 

video_radio_2016_06_13_trans_crop.mp4

Hi Steve,

That looks like a good set up there to be fair.

Did you use any software to get the graph results? If so what are you using for it and what software would you recommend?

On your suggestions I have just ordered this satfinder:

http://www.ebay.co.uk/itm/361468620720?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

should have it by early next week  should I order some coax cable also?

Thanks

Jon

 

[SteveBz]

55 minutes ago, Asur1984 said:

Hi Steve,

That looks like a good set up there to be fair.

Did you use any software to get the graph results? If so what are you using for it and what software would you recommend?

On your suggestions I have just ordered this satfinder:

http://www.ebay.co.uk/itm/361468620720?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

should have it by early next week  should I order some coax cable also?

Thanks

Jon

 

Hi Jon,

I just use Libreoffice (same as MSOffice but free). I just put the numbers in a spreadsheet as you can see and used the chart wizard.

I bought:

- the dish - it came with cable, you'll need a metre or two

- the finder

- a way to power the finder, I used a connector from Wickes, 10cm coax cut from my main length, two rechargeable 9v batteries, 2 crocodile clips and two 9v connectors wired in series.  Most of this comes in the deluxe finder

- a way to take readings, I have a few multimeters lying around, I chose one with a big readout so that a I can see it while manipulating the dish, a mV scale and electrodes with clips.

The back of the finder comes off quite easily, clip the multimeter electrodes to the left and right feeds to the central meter, wire up the batteries to the feeder at the other side from the dish, central wire is positive, wire up the lnb and away you go.

Your dish is parabolic and off-centre.  It will be a little difficult to align. Maybe some sort of marker to cast a shadow would help.

Good luck.

Steve.