Jump to content

Narrowband

Low budget jove receiver?


Recommended Posts

Hello,

I am currently looking (again) for a inexpensive and simple way to get into radio astronomy.

This is one of these projects-I-was-going-to-work-on, and then, other things got in the way... As usual.

The main reason this came up is because I am going to work with kids soon, and daytime visual astronomy is rather limited to the sun or early views of moon and planets. So despite the fact that I bought & built a bunch of telescopes, I thought it would not hurt to consider radio astronomy.

I have done a lot of reading, and basically these three seem the most promising:

-dish + satellite finder (sun)

-wire wound around a Box and conected to a soundcard (vlf, sun)

-Radio Jove (Jupiter, aprox. 20mhz, dipole or frame antenna)

-Jagi, Hydrogen line (did Not find any low budget approach though)

As far as my research goes, radio Jove is the most promising.

It would be fun comparing data (Jove prediction software, formula, visual observation of moon positions...) and maybe we can pick up some other radio activity.

The problem though: The budget is very low for school projects.

I have found a few projects online that utilized a multi band radio for radio jove. I did buy a cheap one but of course it does not have ssb, but am.

Unfortunately my antenna isn't done, so I have no actual experience with it. It's tuning is not the sharpest, but would probably be a good thing to detect those sweeping signals.

http://item.mobileweb.ebay.com/viewitem?itemId=220814282504

Radio receivers that feature usb/ssb seem much more expensive, and thus are not an option. Same with the Jove kits at the moment.

Then the cheap (10-15€/$/£) dvb TV USB sticks caught my attention, a lot of people seem to be using a few of them for all sorts of stuff, as some versions basically allow software defined radio for 60-1400 MHz, but especially below 50MHz they seem to be so poor that it's no use. At least for use around 20 MHz.

I did read some articles to building frequency downconverters, and while I can read circuit diagrams and solder, I have never build more then a few basic radio circuits as kid, and anything that goes beyond a finished circuit fails due to the lack of the hf knowledge.

After searching around some more, especially regarding ssb receivers, I found

http://homepage.eircom.net/%7Eei9gq/regen.html

And this would be the right skill Level to build it with students. Any idea if this could work, with the right changes to receive Jove signals?

Or any ideas for other receivers?

Thank you in advance

-Marcus

Link to comment
Share on other sites

  • Replies 33
  • Created
  • Last Reply

Hi Marcus

Good luck with your project. I have no knowledge of this area, but I do remember that there was a set up at PSP last year. I found these links online, maybe you could contact them for advice?

http://www.radioastronomy.me.uk/

http://www.radioastronomy.me.uk/Analysis_of_Data_from_Radio_Jove_at_Peak_Star_Party_2012-10--19-22-.pdf

Cheers

Stu

Link to comment
Share on other sites

Hi, your research is not far off the mark. The Hydrogen line would be out of the question on a low budget. The easiest RA scope to put together and get working is the Dish and finder, although it is pretty limited to strong radio sources like the sun and gives instant results.

As for Radio Jove antenna wise would have to be a dipole for good results nothing smaller, cut for the frequency. A dipole placed North to south will pick up most signal from East to West and viceversa.

You could have a go with the radio you have and let it run for 24 hrs then see whats on the trace recording. As you say a radio with SSB with AGC off control is the ideal as the AGC defeats what your attempting to record.

My advice would be to contact you nearest Amateur radio club. They will gladly offer advice on receivers and kits and would always be happy to assist schools. They may be able to source you used radio equipment suitable for your project. They also may be in a position to loan equipment for you to use.

Hope this is useful

Carl

Link to comment
Share on other sites

Hello Stu,

thank you, I will read through those when I'm back on my computer, and I'll consider doing that :-)

Hello Carl,

thank you as well for your reply!

I do have a old dish and analog finder, so that's something I will most likely do; As you mention, it's a bit limited.

As for the Jove antenna, hopefully it can be set up here and somewhere where is little interference and a save place to store radio and recorder :-)

I read that those little panel/loop antennas should be avoided, though there is one sucessfull report online, using a (better) mutli band music radio receiver. So I wonder what's possible in case we can't set up a wire around here.

Thanks for the advice with the radio club, So far I only have talked to a single person who's into ham rafdo but did not seem too enthusiastic about it. But in a club I might find other people.

I do wonder why there's no simpler receiver circuit for Jove though. And perhaps one of those ham/circuit gurus on here could tell me if the

regenerative trf receiver or similar could work.

Nothing has to be perfect, and for kids the do-it-yourself aspect is great, even if rhe result is not perfect. And if it's too complicated or out-of-the-box it get's borring soon.

Link to comment
Share on other sites

Thank you for the Link, I was not aware that the funcube now supports low frequencies :-)

Unfortunately one, not to mention six or more, are way above the budget. Perhaps I'll buy one when my own funds are recovering, but after buying a bunch of telescopes and moving tt is out of the question for now...

Are there any of new tv USB dongles that support anything under 50MHz now?

Link to comment
Share on other sites

Hi Marcus

If you can stand the pace, I did a thread about this quite a while back

http://stargazerslou...adio-astronomy/

Problem with Jupiter reception is that not a lot happens most of the time and as such, might not keep

your students interested..

Solar activity is a bit more dynamic so is a better choice IMHO.

Also, you might consider detecting meteor reflections as that happens day or night...

The frequency for this is 143.05 USB so with a bit of tinkering you could use a cheap TV dongle, some

free software and a cheap 2 element aerial which neednt be mounted high up..

http://astrochat.co....pic.php?t=16921

Good luck with your projects

Philip G4JVF

Link to comment
Share on other sites

Hello Philip,

thank you for your advice.

I have read the thread and posted there when I started my experimenting :-)

But other things got in the way so I am almost at the same position as back then.

Meteor reflections is something I will read up on, it indeed sounds interesting if it'll work with the cheap dongles. Though by now there's probably hundreds more to choose the right one from...

Yes, Jupiter activity is limited, but along with prediction software, visual observation and solar system discussion I'd like to include it.

Of course two or three different projects would be nice and also increase chances of an actual sucessfull ovservation.

Link to comment
Share on other sites

Hi Marcus,

Can I point you in the direction of - "A simple Decametric Radio Telescope for Jupiter".- see www.ukaranet.org.uk/uk_amateurs/bobgreef/

This is a simple, easy to construct, and cheap introduction to listening to "Radio Jupiter". The most expensive item is probably the SW radio which will work around 20Mhz to enable you to hear the "waves on a stony beach" sounds of Jupiter. Try and get a radio with an external aerial input, this will make things easier when connecting to your loop aerial. There was also a QBasic programme that enabled you to calculate emission detection times. If you, or anyone else is interested, I'll try and relocate this little gem.

Best wishes,

Les

Link to comment
Share on other sites

Thank you for the Link, les;

i have Seen that One, and it was the reason I ordered the cheap 11 Band receiver;

http://ringohr.de/tmp4/boxtenna/klappteleskop2d_grouped_reassemble_2.png

Due to lack of time and other stuff it's not finished, and also many sources online claim that this setup will not work.

But on there the results seem good, and the loop antenna seems to be from some magazine.

I am no antenna expert, but I do know the antenna is not ideal... But a coathanger isn't either for radio receiption, yet it works if nothing else is at hand ;-)

The antenna and my receiver are two unknown variables, making it difficult to evaluate what will cause problems...

I do have the qbasic script and the shareware Jove forecast program, but as both do produce different results, it's probably just best to go ahead and record for some time :-)

Link to comment
Share on other sites

Hi Geppetto,

Yes, the little beast works. It's a cut down version,(approx 3ft sq), of your posting from back in Oct 2010, assuming I'm talking to "THE" Geppetto. Can I just say it's due to stumbling across those postings, that my long smoldering interest in "simple" radio astronomy got re ignited and following our move to Wales, I've now got some space in the ever decreasing garden to do something. Thanks for firing my enthusiasm.

I use a cheap Lidl/Aldi SW receiver with an external aerial input, so the coax is simply soldered to a suitable phono plug, rather than removing the existing aerial and making the contacts there.... simples!! One thing I note however, Use the receiver with internal batteries. As soon as you plug in the mains adaptor, the reception just got "mushed up"..... probably not the correct technical expression, but certainly what happens for me.

I can "hear" the waves on a pebble beach sounds from Jupiter with this set up. What helps to improve things is also knowing the best times to hear the emissions. In an article from Sky and Telescope entitled " Detecting Jupiter's Radio Emissions" by Mal Wilkinson and John Kennewell, there is,as well as a wealth of easily understandable information , a QBasic prog to calculate the emission times.

I suspect that many people try these easy radio telescopes, half expecting to hear nothing and give up after a couple of attempts because they've simply been listening at the wrong time. It's also fair to note that due to the very wide "seeing" area of the loop antenna that if Jupiter, in my experience, is closer than some 45 degrees to the Sun, that the Sun will swamp the Jovian signal so again you'll not get the crashing waves effect.

Try these and persevere..... they will work!!!

Best wishes, Les

Link to comment
Share on other sites

Marcus,

The simple loop antenna relies on the "pure grunt" of the Jovian emission. As I've just been talking to Geppetto about, things like the Sun, a Mains power feed to your SW Radio or other power emissions near by can effect the simple little loop reception.

Regarding the emission time progs, being a tightwad, I've only tried the free QBasic prog and this does seem to work quite well for me.

Keep trying, the system will work!!

Regards, Les

Link to comment
Share on other sites

Hi Geppetto,

assuming I'm talking to "THE" Geppetto.

Yep that's me....there can be only one :)

Interesting stuff Les...

Pleased to hear the little loop worked for you, I'll have to have bash at making one.

My BIG loop worked but it was experiment only and it was too big to stay in the garden.

Not all a loss though as the reflector frame with the chicken wire is now holding up a rather nice display of sweet peas..

All good fun this...

Philip G4JVF

Link to comment
Share on other sites

I have had a quick look through the posts and apologise if what I am just about to say has already been said. Jupiter is horrendously difficult to pick up - as anyone who came to my radio astronomy tent as the Peak Star Party last year will have seen. Requires low level of radio interference and we still had siginificant amounts of that in a field in Derbyshire! The Radio Jove receiver set up (which I have) requires two large antennae some 20x10m plus supports and any other antenna is less effective, unless you go for a large purpose-cut Yagi (dishes do not work as frequency too low......although there is thermal radition at higher frequencies). Another problem is the receiver - needs to be broadband (ie collect radio signals across a wider spectrum that modern narrow band receivers such as ICOM receivers) - you can pick up reception from Jupiter with a ham receiver but the narrower band reduces the likelihood of success.

.....Don't get me wrong, you may succeed. My set up may not often pick up Jupiter but it picks up excellent solar flares. But then I could do that with a SID receiver - smaller, cheaper and wife is happier.

My penniworth - try a SID receiver first eg the sold by UKRAA, then go for meteor scatter, before trying for Jupiter - but whatever you do, enjoy it - and if you really want to try for Jupiter ignore me and just do it anyway! Just let me know how you get on.

Andy

Link to comment
Share on other sites

Thank you for your thoughts on the subject and insight!

Of course, half the fun will be building and running around on a field. It's a school project, and as it is just one aspect of it, I think it will be sufficient. But perhaps we can get something, that would be nice. I will consider your reccomendations.

Also, budget is deployed by the optical telescope kit... So something like simple VLF receiver (Wire around a box plugged into the soundcrd) and using the (not so narrow band-ish) cheap chineese radio are probably the weapons of choice.

It will be far from perfect, but it's more or less allready here or cheap to aquire.

I like minimalist projects, but of course, the results may be poor. Perhaps, in the long term, we will be able to buy some better equipment. This would be great :-)

I alread bought 5 x 5" newtons (from my own money for the work with kids) so I can't spend much more, as I already mentioned I think.

I am just trying to use the little budget and materials as creative as I can ;)

Link to comment
Share on other sites

I would recommend getting a supersid receiver from the USA - relatively cheap and very effective, easier to tune than the Ursa receiver and picks up multiple channels allowing you to discuss triangulation data with your students. If you have a field then the radio Jove does become practical - in fact the process of building it with the students in educational - but they really need to to A level standard to participate. I have built two radio Jove receivers so far and there is quite a learning curve if you are not already experienced at electronics. However still practical to do.

Andy

Sent from my iPad using Tapatalk HD

Link to comment
Share on other sites

In the long term I might be able to get into it a Bit more, and with more cash, as well. Right now i'd say 50€ would be the Maximum.

Also, as with every school project, getting One kit is Not ideal, 10 Kids on One receiver would Not work... Thus the reason I bought the kk11 for $6 but was Not able to try it out yet for ra.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.