2. Where Should I Set-Up?
Your success in hearing Jupiter and the Sun will depend in part on picking a good radio quiet location to set up your radio telescope. There are many sources of interference that can completely mask the signals that you are trying to hear. Arcing insulators on power lines are one of the worst. There are many others including light dimmers, electric fences, automobile ignition systems, electrical machinery, computers, arc welding equipment, bad fluorescent light starters, etc, etc.
Keep these potential radio noise sources in mind when you choose an observing site. As a general rule it is a good idea to get as far away as possible from power lines, busy highways, buildings full of computers, or industrial sites with electrical machinery. The middle of an athletic field may be a good choice, or a residential area with underground power, or perhaps a rural setting. The radio Jove antenna was designed to make it easy to go to a “remote” radio quiet observing site.
The Jove antenna kit comes with a 1-wavelength piece of coaxial cable 9.85 meters long (velocity factor 66%) used to connect the receiver to the antenna. This relatively short cable may present a problem if you want to use the receiver and a computer indoors but are located more than 30 feet from the center of the antenna. The cable going from the antenna power combiner to the receiver can be longer than the cable supplied, but it should be a multiple half wavelength long, and no longer than 5 wavelengths. There are many different manufacturers and qualities of coaxial cable. The 75-ohm cable supplied with the kit is manufactured by Belden and has a solid center conductor and velocity factor of 66%. Radio Shack does not carry RG59/U cable but they do have RG-6 and the higher grade RG-6QS (quad shield), which is also 75-ohm cable. Both of these cables have a velocity factor of 78 percent. One wavelength at 20.1 MHz in RG-6 cable is 11.64 meters. If you are going to use a longer feed line we recommend completely replacing the existing 1 wavelength piece, rather than splicing another length of cable onto the end. By replacing the cable supplied with the kit you could locate the antenna up to 58 meters (190 ft) away from the receiving electronics.