**Radio Jove**

**Antenna Manual Supplement**

##### READ BEFORE ASSEMBLING ANTENNA

January 2006

## Introduction

Now that your receiver is built, you need to choose the best antenna
system to fit your needs. Your antenna kit contains materials for 2
dipoles. You have a couple of options as to how to proceed.

**Single Dipole** You can construct a single dipole, for observing the
sun.  It can be quickly setup at reduced expense and takes half the
space of the dual dipole array (10 ft x 32 ft vs. 30ft x 45ft). You can
observe the sun during daylight hours and with patience you will capture
solar bursts. You can run drift scans of the galaxy and observe various
effects of the earth's ionosphere.  The downside of the single dipole is
that, since it has low gain you will see only the stronger solar bursts
and rarely any Jupiter activity.

**Dual Dipole Array** The full RJ1.2 dual dipole phased array will allow
monitoring of both Jupiter and the Sun.  Its larger size and increased
sensitivity mean better reception of Jupiter and solar bursts.  Galactic
drift scans will be more detailed. The dual dipole array will require a
greater expense for supporting masts as well as more real-estate than
the single dipole. Some student groups may have difficulty making
Jupiter observations as these occur in the late night or early morning
hours.

## 

## Picking a Site

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. However, we have had some
good successes with Radio JOVE antennas near buildings; local conditions
are extremely variable and trial-and-error may give you good results.

## Choosing an Antenna

The Jove antenna kit contains wire, insulators, coaxial cable,
connectors and a power combiner -- all the materials necessary to
assemble the electrical parts of the dual dipole array -- or the single
dipole antenna. If you decide to start with the single dipole you can
complete the second dipole later.

All of the information you need to assemble the dual dipole array is
found in the accompanying RJ1.2 Assembly manual. The single dipole Sun
antenna is described in the remainder of this supplemental document.
Construction time for this single dipole will run approximately 3 hours.

# 

# Radio Jove

**Single Dipole Antenna for the Sun**

## Getting Ready to Build the Single Dipole Antenna

Please read sections 1.1 - 1.4, 2.3, and 2.4 in the RJ1.2 antenna manual
before continuing.

## What Parts are Needed?

The following list identifies all the materials supplied with the Jove
RJ1.2 antenna kit. Materials which you will use for the single dipole
are identified in the right hand column.

+-------+---------------------------------------------+-------+-------+
| For   | Parts included in the Radio JOVE Antenna    | For   |       |
| Dual  | Kit                                         | S     |       |
| D     |                                             | ingle |       |
| ipole |                                             | D     |       |
|       |                                             | ipole |       |
| Array |                                             |       |       |
+-------+---------------------------------------------+-------+-------+
|       | Description                                 |       |       |
+-------+---------------------------------------------+-------+-------+
| 50 ft | 50 ft. (15.24 m) #14 Gauge Stranded Copper  | 25 ft |       |
|       | Wire                                        |       |       |
+-------+---------------------------------------------+-------+-------+
| 95 ft | 95 ft. (29 m) RG59U Coaxial Cable (Belden   | 95 ft |       |
|       | 8241)                                       |       |       |
+-------+---------------------------------------------+-------+-------+
| 4     | PVC End Insulators (cylinders)              | 2     |       |
+-------+---------------------------------------------+-------+-------+
| 2     | Plastic Center (dogbone) insulators         | 1     |       |
+-------+---------------------------------------------+-------+-------+
| 6     | Twist-on F-connectors                       | 3     |       |
+-------+---------------------------------------------+-------+-------+
| 1     | Coaxial cable coupler                       | 1     |       |
+-------+---------------------------------------------+-------+-------+
| 1     | Power combiner / splitter (2-to-1)          | NA    |       |
+-------+---------------------------------------------+-------+-------+
| 6     | Ferrite toroid cores                        | 3     |       |
+-------+---------------------------------------------+-------+-------+

You will need to purchase the following materials to complete the single
dipole antenna.

  ----------------------------------------------------- --------- --------
  Parts necessary but NOT included with the Radio JOVE            
  Antenna Kit                                                     

  1 60 ft. (15.24 m) x 3/16 in. Nylon Rope                        

  2 10 ft. (3.048 m) x 1 in. PVC pipes (Sch 40)                   

  2 1 in. PVC End Caps                                            

  2 1 in. PVC Couplers (Optional for portable use)                

  2 4 in. x 3/8 in. Bolts                                         

  2 3/8 in. Nuts                                                  

  2 3/8 in. Flat Washers and Lock Washers                         

  4 4 in. x 1/4 in. Eye Bolts                                     

  4 1/4 in. Nuts, lock-washers and flat-washers                   

  1 Small can of PVC Cement (optional)                            

  3 Tie wraps (optional)                                          

  4 Tent stakes                                                   
  ----------------------------------------------------- --------- --------

## Building the Single Dipole Antenna

Take a few minutes to study the following diagram. This is the dipole
antenna that you will be building. The antenna will be installed, with
the wire running E-W, on a site approximately 32 ft E-W by 10 ft N-S.

![](media/image1.wmf){width="6.0in" height="8.653472222222222in"}

### Wire and Coaxial Cable (Use the o markers to check off each step as you complete it.)

**Cutting the Wire, Coax, and Rope**

1\. o Cut 2 pieces of copper wire each to a length of 12 ft. 4 in. (3.76
m). This length includes 5 inches extra on each end for attaching to the
insulators.

2\. o Cut 1 length of coaxial cable 32 ft. 4 in. Referred to as the
1 λ (lambda) cable. The remaining cable (about 60 ft) can be used to
connect the antenna to the receiver.

3\. o Cut two lengths of rope, each 2 ft. (0.61m). Melt the ends with a
lighter to keep from fraying.

**Wrapping the Insulators**

1\. o Attach an end insulator to each wire. Thread 5 in. (12.7 cm) of
copper wire through the hole in the end insulator and wrap it back on
itself as seen in figure 3.1a.

2\. o Thread each rope through an end insulator (fig 2a). Tie using 6
in. of rope for each knot).

3\. o Attach the pair of wires to the center insulator (fig 2b). Thread
5 in. (12.7 cm) of copper wire through the hole in the center insulator
and wrap the wire back on itself as seen in Figure 3.1b.

4\. o The total length of the dipole wires (from one end insulator to
the other end insulator) should be 23 ft. 3 in. (7.09 m). Ropes should
extend about 1.5 ft (45 cm) from each end insulator.

![](media/image2.png)![](media/image3.jpeg){width="3.067361111111111in"
height="1.7145833333333333in"}

Figure 2a and 2b. Wrap the end and center insulators with the antenna
wire.

**Preparing and Soldering the 1 λ Coax lines**

1\. o Remove 5 inches (12 cm) of the outer insulation from ***one end
only*** of the 1λ cable. Be careful not to cut the braided copper wires
underneath.

2\. o Unweave the braided copper shielding using a small screwdriver or
the tip of a pen or pencil. Start at the end of the wire and carefully
unbraid all of the exposed copper shielding (Figure 3a and 3b). A few
broken strands of braid are normal.

![](media/image4.png)

Figure 3a and 3b. Unbraid and twist copper shielding.

4\. o Strip off the insulation around the center conductor approximately
1 inch (2.5 cm). This is polyethylene and is fairly tough, so use a
sharp knife with caution. **WARNING: *Be careful not to nick the center
conductor when cutting and stripping off the insulation around it.***
Nicking the center conductor will weaken it and most likely cause it to
break after swinging in the wind.

5\. o Loop the coaxial cable over the center insulator and tie wrap or
tape it (Figure 4) just below the section of stripped coax. This will
provide strain relief so the solder joints will not break.

6\. o Wrap the bare center conductor around the end of one of the copper
wires attached to the center insulator. Wrap the twisted shielding
around the other copper wire attached to the center conductor.

7\. o If necessary, clean the ends of the wire with sand paper. Solder
the coax center conductor and shield to the copper wires (we recommend
using a soldering gun). Use plenty of solder and heat the wires until
you see the solder seep into the wires.

![](media/image5.jpeg){width="3.986111111111111in" height="2.65625in"}

Figure 4. Attach the 1 λ coax to the center insulator

**Installing the Ferrite Beads**

1.o Slide 3 ferrite beads up the cable to the very top of the coax near
the dipole. Secure them all in a row with tape and a tie wrap.

## Installing the F-Connectors 

1\. o Remove 1 inch (2.5 cm) of the coax outer insulation (fig 5a).

2\. o Unbraid about half of the exposed shielding and fold it back over
the other half of the copper shielding and over the outer casing (fig.
5b)

3\. o Remove the insulation around the center conductor leaving about
1/2 inch (1.3 cm) of bare center conductor (Figure 5c, 5d).

4\. o Push the F-connector over the end of the coax and twist on as
tightly as possible.

About 1/8 inch (0.3cm) of center conductor should stick out of the end
of the F-connector (Figure 5e).

5\. o Repeat this connector installation procedure for each end of the
long cable which will run to the receiver.

![](media/image6.jpeg){width="1.90625in" height="1.38125in"}
![](media/image7.jpeg){width="2.026388888888889in"
height="1.3409722222222222in"}
![](media/image8.jpeg){width="1.9666666666666666in"
height="1.3451388888888889in"}

![](media/image9.jpeg){width="2.452777777777778in"
height="1.6236111111111111in"}
![](media/image10.jpeg){width="2.452777777777778in"
height="1.6284722222222223in"}

Figure 5a --e. Prepare the coax and install the F-connector.

**MAST PREPARATION** (refer to figure 1)

Start with one 10-foot PVC pipe and pick one end as the dipole end.

**A. Dipole End**

1\. Drill a ¼" hole, two inches from the end of the mast (hole A). Drill
another ¼" hole (hole B) twelve inches from the end of the mast (and
parallel to hole A).

2\. Install one 4"x ¼" eye-bolt in hole A with the eye inward for the
dipole. Use a flat washer, lock washer and nut to secure the eyebolt.
Install and secure an eyebolt in hole B with the eye outward for the guy
rope.

**B. Ground End Cap**

1\. Drill a 3/8" hole directly in the center of the PVC end cap.

2\. Install and secure a 3/8 x 4" bolt into the cap hole (see figure 1).

3\. Glue the end-cap with protruding bolt to the ground end of the mast.

This completes the first mast. Prepare the other identical mast.

If you plan to cut the masts in half for portability do so now. Install
and glue a coupler onto the top of the bottom section of each mast.

#### **PREPARING the SITE**

Before the antenna can be assembled and raised, you must layout the
antenna field. Study Figure 6, noting that the antenna wires run in an
East-West direction. Proceed as follows.

1.  A magnetic compass, a 50-foot measuring tape, and a couple of
    helpers will make quick work of laying out the site.

2.  Determine the mast and guy stake locations on the antenna field. Use
    one of the guy stakes to create a small hole at each mast mounting
    point. (Then remove the stake -- these holes are where you will
    insert the spikes on the bottom of the PVC masts. Hammer in the guy
    stakes (with the top of each stake tilted outward from its mast at
    about a 45 degree angle). The antenna field is now ready for
    installation of the masts and dipole

Figure 6. The antenna site showing the location of stakes and masts. The
minimum site size required to erect the dipole is 10 by 32 ft. The
dipole should be at least 10 to 15 ft from the nearest parallel metal
fence or sizable metal object. Exercise caution erecting the dipole.
Stay well away from power lines -- **warning** -- electrocution hazard.

## WEATHERPROOFING THE ANTENNA

# It is important to weatherproof the coaxial cable connections at the antenna feedpoint and the cable coupler, particularly if the antenna will be subject to moisture. Simply wrapping them in electrical tape will help, but a better solution is to use Radio Shack Coax Sealing tape. The rubberized plastic compound sold at hardware stores to insulate tool handles makes a great outer coating on top of the tape and will help ensure complete protection from moisture penetration.

**MAST and ANTENNA INSTALLATION**

**[Read all installation instructions before starting.]{.underline} Do
not attempt installation of antenna masts with fewer than 3 people.**

**DO NOT INSTALL NEAR POWER LINES**

**ITEMS NECESSARY ON HAND:**

2 masts, dipole assembly (includes the soldered one-wavelength coax and
ferrites), all coax cable with F-connectors attached, rope, sharp knife,
lighter (After cutting the rope, melt the ends with the lighter to keep
the end from unraveling).

**Step 1**. Lay out the masts, with the base of each mast near its hole.
Stretch out the dipole. Attach one end of the dipole rope to its mast
using the top eyebolt. Do not connect the other end of the dipole to its
mast yet.

**Step 2.** Cut two 26 ft long guy ropes, one for each mast Pass each
guy rope thru its eyebolt, and then loop back thru the eyebolt so the
center of the rope is secured by the double loop at its midpoint. You
should end up with two equal lengths of rope coming from the lower
eyebolt on each mast.

![](media/image11.jpeg){width="3.7in" height="2.323611111111111in"}

Figure 7. Setting up the mast. Lay out the dipole on the

ground and set up one pole at a time.

**Step 3.** Insert the mast with the dipole wire attached into its hole
in the ground and erect it to the vertical position. Tie guy ropes to
their stakes so that the mast is approximately vertical.

**Step 4.** Attach the dangling end of the dipole to its mast. Stick the
second mast into its hole, and secure the guy ropes so that the mast is
approximately vertical. The antenna should be fairly taut with both
masts near vertical. If it is not, move one mast as needed along the E-W
line, reinsert in ground, and retie the guy ropes.

**[USE CAUTION -- BE SURE THAT GUY ROPES ARE SECURE.]{.underline}**

**Step 5.** Adjust all guy ropes to make the antenna masts vertical. Do
not expect perfectly straight masts, as the PVC pipes will flex one
direction or another.

**Connecting** **Cables to the Radio JOVE Antenna and Receiver**

You can connect the receiver directly to the 1λ cable coming from the
feedpoint or you can extend that cable by attaching the additional 60 ft
section of coax. Use the female/female F-adapter (enclosed with the kit)
to connect the two cables. Make sure that all F-connectors are snug. You
can listen with headphones or an amplified speaker or using the audio
system of a computer sound card. The computer option is described below.
Connect all cables to the receiver as shown in Figure 8.

Figure 8. Connections to the Jove receiver for testing with a computer.

**Note 1.** The computer can be a notebook or desktop running SkyPipe
software. SkyPipe has been tested to run on Windows machines using Win
98 or later and some Macintosh computers running Windows emulation
software

**Note 2.** The12V DC power source can be a lantern battery (EverReady
732, Radio Shack part \# 23-007), or a regulated power supply such as
the Jameco 162996. If you use battery power, test the battery voltage
every few hours to make sure it has not dropped below 11 volts. The Jove
radio should be turned on for this measurement.

**Note 3**. The Jove receiver has two identical stereo audio output
jacks (Audio 1 and 2). Each jack provides the same receiver signal to
both stereo channels (left and right channel). An audio cable connects
the Jove receiver (either Audio 1 or 2) to the computer sound card
input. Desktop computers have *line* and *mic* inputs while laptops
usually have only a *mic* input. The *mic* input is much more sensitive
with mic boost enabled on your sound card control panel. The *line*
input is stereo -- supporting both left and right channels. The *mic*
input is often monaural, supporting only a single channel (left). Your
Windows audio volume control panel selects either *line* or *mic* inputs
to your sound card and SkyPipe (Options\>Source) selects between left
and right channels. You can use either mono or stereo audio cables, but
be sure to check both your Windows Volume Control Panel and SkyPipe
Options to connect the receiver audio to SkyPipe.

Set your receiver volume control to the 12 o'clock position. Adjust your
software volume controls in Windows for a baseline signal around 1000 on
SkyPipe with the antenna connected. You should hear a significant
increase in noise level when the antenna is connected to the receiver as
compared to listening to the receiver with no antenna (Figure 9). If you
do not see and hear this noise increase, then there is something wrong
with either the antenna or the receiver. Check all connections, wires
and cables of the antenna and see the troubleshooting section of the
receiver manual if necessary.

![](media/image12.jpeg){width="6.0in" height="2.75in"}

Congratulations on completing your radio telescope. To monitor the Sun
set the receiver gain to the 12 o'clock position and tune the receiver
to a quiet frequency between stations. Figure 10 depicts three weak to
moderate solar bursts. Each burst typically lasts less than a minute and
often has a rapid onset and then a slow decay in intensity.

![](media/image13.png)

Figure 10. Typical solar bursts -- each burst usually lasts less than a
minute. Bursts may come singly or in groups. Usually there is more
activity when there are visible sunspots on the Sun.

## Always Observe Safely

1.  Avoid Lightning (always disconnect the antenna when not in use, and
    always disconnect the antenna before a lightning storm is present,
    and preferably well before the storm arrives.)

2.  Never assemble the antenna under overhead power lines. The antenna
    should be located as far from overhead power lines as is practical
    -- several hundred feet if possible.

3.  Mark your guy ropes with reflective high visibility tape

## Share Your Data

The Jove team maintains a data archive on the Jove website. You are
invited to submit your records to this archive.

**If you need help** or advice -- contact a Jove team member -- see the
website for details.