Radio Telescopes / Listening to the stars

[ryangassxx]

Anyone have any idea what type of equipment would be necessary in order to set up a very basic rig that could tune into intergalactic radio emissions?

Ever since I saw the movie "Contact" several years ago, I've always had somewhat of an interest in being able to listen to the natural radio emissions or pulsars, quasars, and things of that nature.. Obviously I could never have anything as elaborate as that telescope array in New Mexico, but how about a very basic setup for home?

 

[nec208]

Any scanner should do has there is no emissions in space and space is a vacuum so there is nothing to attenuate the signal.

Well the stars,planets,gravitational waves,black holes,asteroids,cosmic dust and gases do attenuate the signal.

 

[mancow]

Uh no not really.

Space telescopes generally often look at the SHF spectrum which is up in the several Ghz range.

A scanner receiver doesn't have that capability. Most go up to 1.3 Ghz max but at that range they are deaf as a post as even stated by the manufacturers. You would need a high gain antenna with low noise high gain amplifiers and a good receiver matched to the range you are looking at studying. After all of that you would need to process what you receive to glean something that's meaningful.

It's kind of like trying to fly to the edge of space in a bi-plane. It just isn't going to happen. Even man made signals like the Inmarsat fleet are impossible to receive without a decent receiver, a low noise pre-amp and a good antenna.

 

[nec208]

To bad he not on a ISS than he does not need a high gain antenna or receiver.

And yes he will need a receive that can get the Ghz range has most scanner don't go that high.

 

[eorange]

It's absolutely possible. You just need to start closer to home, armed with your shortwave receiver.

In the August 2002 issue of Pop Comm, there was an article about listening to the natural radio signal emissions coming from the planet Jupiter. The recommended range is 20 to 21 MHz AM. The sound is described as a sweeping "lighthouse" effect.

Prediction Tool for Jupiter -> http://www.radiosky.com/rjwsw.html

Great Starter Info -> http://www.spacetoday.org/SolSys/Jupiter/JupiterRadio.html

Also, get your butt outside and monitor the AO-51 ham satellite. Yes it's not in outer space and yes it's man-made, but you'll gain a whole 'nother appreciation for space monitoring when you track the rise, peak, and fall of satellites, with a signal ranging from lots of static, to full quieting, to lots of static (then gone), all in a span of a few minutes. On a good night you can see it as you're listening.

 

[zz0468]

A scanner would be completely useless.

A good place to start would be to google SETI and see what those guys are up to. A very decent 1420 MHz receiver (hydrogen line) with a low noise preamp and a TVRO dish is quite capable of doing some excellent astronomy.

For someone who understands low noise receivers, building something that can actually hear things is quite within the capabilities of the home builder. For example, my 10 GHz ssb rig can hear the black body radiation off the moon with a 4' dish. Sun noise is fun to measure, too. With a larger dish, and a receiver tuned to 1420 MHz, there's more fun to be had. Doubtful you'd be able to hear quasars, but there are some pretty noisy pulsars and other objects that are doable. The 21 MHz Jupiter noise is a good suggestion, too. I'll have to try that for myself.

 

[cpuerror]

I wonder if it would be possible to employ a head used for satellite tv reception to downconvert the signal into something a scanner can handle?

 

[zz0468]

I wonder if it would be possible to employ a head used for satellite tv reception to down convert the signal into something a scanner can handle?

No. A scanner is just not suitable. Radio astronomy is done with AM and ssb (product detector) receivers, and predominantly on frequencies where there are natural emissions to listen to. A very stable and low noise receiver with several AM and SSB IF bandwidths, switchable AGC, and demodulator outputs would be necessary. Some stuff is done with VERY wide bandwidths (like 30 MHz wide) and square-law detectors right at the IF. A scanner just doesn't do all that, and can't be modified enough to do so.

In addition to a REAL receiver and LNA, you need to have a solid grasp of noise figure, and the ability to measure it. Got a noise figure meter and the noise head? Know how to use it? Only then are you on your way...

 

[key2_altfire]

Interesting post. I have often wondered about this.

First of all, you should read a little about "redshift." You know how the Doppler effect works, right? In space, since things are moving away from each other, their electromagnetic emissions are Doppler shifted to a lower frequency (e.g. toward the color red on the spectrum). Background radiation is microwave radiation because the Doppler effect has shifted the EM radiation of celestial bodies so far down the spectrum that they are now in the microwave area.

http://en.wikipedia.org/wiki/Redshift

I think with some research and an appropriate "horn" antenna, you could listen to background radiation. Listening to radiation emitted by a specific body, however, will probably be very difficult.

 

[k8ow]

http://www.setileague.org/

they have everything you need

 

[cjrjr507]

Hi
Go check out this site! www.haystack.mit.edu/index.html
click on astronomy then click on srt; small radio telescope
Very cool! Heck, the whole site is cool.

 

[ryangassxx]

Hi
Go check out this site! www.haystack.mit.edu/index.html
click on astronomy then click on srt; small radio telescope
Very cool! Heck, the whole site is cool.

THAT is what I'm talking about!! Thanks for posting that... I would love to have one of those.. Pretty expensive though.. $7,500.. If I had a spare $7,500 though, i'd probably buy it..

 

[WA1CRZ]

Do like Charlie Sheen did in the movie "The Arrival"
Just link up a bunch of neighborhood satellite tv dishes

 

[ryangassxx]

Do like Charlie Sheen did in the movie "The Arrival"
Just link up a bunch of neighborhood satellite tv dishes

I don't know if you're kidding or not..

 

[kmacka]

Do like Charlie Sheen did in the movie "The Arrival"
Just link up a bunch of neighborhood satellite tv dishes

The movie "The Arrival" is actually based on a true story.

 

[ryangassxx]

The movie "The Arrival" is actually based on a true story.

Yeah thats right I remember seeing that,... I wonder just how much of the story was real though.. When they say "based on", that could mean that the color shirt the guy was wearing was the same..

 

[n2mdk]

Yeah thats right I remember seeing that,... I wonder just how much of the story was real though.. When they say "based on", that could mean that the color shirt the guy was wearing was the same..

Yes Aliens with knees that bend the wrong way, really did try to take over the Earth. Not only that the actor Ron Silver is indeed an actual extraterrestrial.

 

[k9rzz]

A nice test signal is the Inmarat satellites. While there isn't any more analog stuff to hear, really, the digital sigs are a nice target to test your setup.

http://radioreference.com/forums/showthread.php?t=68142