Dipole antenna for jupiter

[sungrazer (Karen)]

Hi

I am looking to build a dipole antenna to listen to jupiter. I am putting in the poles and antenna tomorrow.

Now for the harder part - getting it to work. What are your suggestions please for buying the receiver and amplifier. I do care about price but not that much that I need to buy second hand etc.

Since I am just getting started I would appreciate any suggestions / advice you all might have.

thanks
Karen

[mswhin63 (Malcolm)]

Reasonble skill needed for this project

http://www.altronics.com.au/index.as...=item&id=K1127

[sungrazer (Karen)]

Hi
thanks
I have a track record of involving my 10 yr old nephew with projects like this so I may just buy this kit.

Would i be right in thinking this has the pre amp in it or do I need one of those as well?

What would be the equivalent off the shelf item?

thanks again
Karen

[AussieSky (Greg)]

You wont need a pre amp with the Altronics kit. Its almost exactly the same thing as the proper 'Radio Jove' receiver.
Make sure that the antenna (I presume your using the Radio Jove design twin dipole) and the co-ax downfeed are cut to the exact length for the frequency your working with (20.1 Mhz ?).

The coax from the splitter to the receiver of the Radio Jove antenna needs to be an integer multiple of the wavelength to which the antenna and receiver are tuned. Our target frequency is 20.1 MHz or a wavelength of 3 x 10^8 / 20.1 x 10^6 = 14.925m. This is multiplied by the velocity factor of the coax to compute the actual length of coax required. For example, coax with a velocity factor of 66% needs to be units of 14.925 x 0.66 = 9.85m long.

Greg

[sungrazer (Karen)]

Hi,

Thanks Greg.

I am planning on a dipole arrangement. You're right.

I think I will get the altronics kit.

What do you think of a single dipole arrangement rather than the dual? Signal too small/weak?

Also I cant see anywhere it says how far apart the dipoles have to be? is there some formula as well? Im not sure I want to turn the yard into a full time antenna :-)

Finally - If I make the height of the dipoles 4 meters instead of 3 does that matter much?

cheers
Karen

[AussieSky (Greg)]

The twin dipole arrangement gives greater signal strength, and allows you to 'steer' the antenna.
The dipoles on my setup are 6M apart, and the masts are 3M high, but 4 should be ok.

There is a lot of useful info here:

http://radiojove.gsfc.nasa.gov/help/help.htm

and the antenna construction manual is here in pdf format:
http://radiojove.gsfc.nasa.gov/telescope/ant_manual.pdf


Heres a pic of my setup:

www.aussiesky.net/misc/Jove_antenna1.jpg

Greg

[DavidU (Dave)]

Great setup Greg.

[bloodhound31]

I had a bit of a dabble in it a little while ago...

http://www.asignobservatory.com/inde...=article&id=44