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<P class=head><B><FONT face=Verdana>Loop Antennas</FONT></B></P><FONT
face=Verdana>Loop antennas are a very controversial topic among Jupiter radio
astronomers.<BR>Some say it works, some say it doesn't - if it works for you,
compare your results with those from people with dipole(s) or yagi's made during
a coordinated observing session (announced on the RadioJOVE maillist) and let us
know the results on the RadioJOVE maillist, SARA maillist or in the </FONT><A
href="http://www.jupiterradio.com/j/forum/"><FONT
face=Verdana>forum</FONT></A><FONT face=Verdana>.<BR><BR>
<HR>
<IMG style="WIDTH: 426px; HEIGHT: 292px" height=259
src="http://www.jupiterradio.com/antenna/LOOP.JPG" width=375> <BR>
<HR>
</FONT>
<H1><FONT face=Verdana>SIGNALS FROM SPACE</FONT></H1>
<P><FONT face=Verdana></FONT>
<H3><I><FONT face=Verdana>IS ANYONE OUT THERE?</FONT></I></H3>
<P><A href="http://www.jupiterradio.com/jove-loop-antenna.php#connect"><FONT
face=Verdana>[Connections]</FONT></A><FONT face=Verdana>, </FONT><A
href="http://www.jupiterradio.com/jove-loop-antenna.php#challenge"><FONT
face=Verdana>[Challenge]</FONT></A><FONT face=Verdana>, </FONT><A
href="http://www.jupiterradio.com/jove-loop-antenna.php#flash"><FONT
face=Verdana>[Flash Fact]</FONT></A><FONT face=Verdana>, </FONT><A
href="http://www.jupiterradio.com/jove-loop-antenna.php#teacher"><FONT
face=Verdana>[Teacher's Notes]</FONT></A><FONT face=Verdana> </FONT></P><FONT
face=Verdana>
<HR>
Listen for signals from Jupiter with: </FONT>
<UL>
<LI><FONT face=Verdana>6 pieces of wood 4 cm x 8 cm x 183 cm (for square
frame) </FONT>
<LI><FONT face=Verdana>5 pieces of wood 4 cm x 8 cm x 80 cm (for upright
supports) </FONT>
<LI><FONT face=Verdana>U bolts (optional) </FONT>
<LI><FONT face=Verdana>4.2 m of 1 cm (3/8 ") soft copper pipe (plumbing
supply) </FONT>
<LI><FONT face=Verdana>4 sq. m wire mesh (hardware cloth at hardware store)
</FONT>
<LI><FONT face=Verdana>2.5 m twin lead antenna cable </FONT>
<LI><FONT face=Verdana>portable radio with short wave band (SW 2) </FONT>
<LI><FONT face=Verdana>assorted nails, screws and staples </FONT></LI></UL>
<P><FONT face=Verdana><IMG height=365
src="http://www.jupiterradio.com/antenna/Antenna.gif" width=592 align=bottom
border=0> </FONT>
<P><FONT face=Verdana></FONT>
<OL>
<LI><FONT face=Verdana>Nail together the 183 cm square base. </FONT>
<LI><FONT face=Verdana>Nail on the 5 upright supports. </FONT>
<LI><FONT face=Verdana>Turn the base over and staple the screen to the bottom.
The screen completely covers the bottom of the base. This screen is called the
reflector. </FONT>
<LI><FONT face=Verdana>Attach the antenna loop to the uprights with the U
bolts. If you don't have U bolts, tie or wire the antenna loop in place. The
distance from the wire mesh to the antenna loop is 68.6 cm. </FONT>
<LI><FONT face=Verdana>Attach the twin lead antenna cable to the open ends or
the antenna loop. You can do this by inserting the bare ends of the antenna
cable into the open ends of the tube. Then, flatten the tube onto the wire
with pliers, or use a large screw inserted into the ends of the tube. </FONT>
<LI><FONT face=Verdana>Connect the other ends of the antenna wires to the
radio. If your radio has a special place to connect an extra antenna, use
that. If your radio just has a stick antenna, wrap 2 meters of insulated wire
around the antenna. Attach the antenna cable to this wire. </FONT>
<LI><FONT face=Verdana>Turn on the radio and select SW 2. Look closely at the
numbers beside SW 2. They are 16 M to 49 M. Turn the volume up and tune
towards the 16 M end of the dial. Your antenna will work best here. </FONT>
<P><FONT face=Verdana><IMG height=182
src="http://www.jupiterradio.com/antenna/short.gif" width=295 border=0>
</FONT></P>
<LI><FONT face=Verdana>Turn the tuning knob slowly as you listen. You should
be hearing interesting sounds like hums, hisses and chirps, maybe even some
foreign languages. You are detecting a variety of electromagnetic signals.
Some might be coming from radio stations halfway around the world. Some could
be secret codes from spies. Others will be signals from electrons stopping and
going inside the machines close to you. Your refrigerator sends out signals
and so does the transformer on a pole outside. But some of these sounds are
signals arriving from planets and stars deep in space! </FONT>
<LI><FONT face=Verdana>This antenna is designed to detect radio storms on
Jupiter. You can check this out for yourself. First, find out where in the sky
Jupiter appears. Then, tune the radio to a spot where nothing else is
interfering. All you should hear is a steady, gentle hiss. Now, point the
antenna at Jupiter and listen. If a radio storm is happening, you might hear
something. </FONT></LI></OL><FONT face=Verdana>
<HR>
</FONT><A name=connect>
<H2><FONT face=Verdana>CONNECTIONS</FONT></H2></A>
<P><FONT face=Verdana>Many scientists believe that other intelligent forms exist
in the universe. They are using enormous radio telescopes that are aimed into
space. With these sensitive instruments, they listen constantly for
electromagnetic signals. Perhaps there are aliens trying to communicate with us!
They could be using electromagnetic signals like we do. We will never know
unless we listen! </FONT></P><FONT face=Verdana>
<HR>
</FONT><A name=challenge>
<H2><FONT face=Verdana>CHALLENGE</FONT></H2></A>
<P><FONT face=Verdana></FONT><EM>
<OL>
<LI><FONT face=Verdana>Build a scale model of this antenna. Use cardboard,
popsicle sticks, wire and your imagination. </FONT>
<LI><FONT face=Verdana>Create a message that you would send out into space.
Who might receive this message? How can you send it? </FONT></LI></OL></EM><FONT
face=Verdana>
<HR>
</FONT><A name=flash>
<H2><FONT face=Verdana>FLASH FACT</FONT></H2></A>
<P><FONT face=Verdana>Dave Hieserman wrote a book called Radio Astronomy for the
Amateur. He says, "for the amateur radio astronomer, Jupiter is perhaps the most
exciting and delightful radio source. Through a speaker, Jovian broadcasts are
frequently reproduced as seashore sounds or very distinctive chirps or staccato
noises." There are so many sources of electromagnetic signals that you might
never be certain that you have heard Jupiter. But it sure is fun to try!
</FONT></P><FONT face=Verdana>
<HR>
</FONT><A name=teacher>
<H2><FONT face=Verdana>TEACHER'S NOTES</FONT></H2></A>
<P><FONT face=Verdana>This sophisticated project appears in the TAB book, Radio
Astronomy for the Amateur. The antenna was designed by a university student as
part of his work for his master's degree. The antenna was intended to detect
electromagnetic signals from the planet, Jupiter. </FONT>
<P><FONT face=Verdana>All objects in space give off electromagnetic signals.
Scientists who study these signals are called radio astronomers. Some
astronomers are involved in a program called SETI, Search for Extra Terrestrial
Intelligence. They are trying to detect signals from other intelligent life
forms. </FONT>
<P><FONT face=Verdana>This is a difficult search. An endless array of signals
comes from all over the universe and the distances are vast. Even though
electromagnetic signals travel at the speed of light (299 791 km per second), it
takes these signals years to travel from the closest stars outside our solar
system. If astronomers detected a signal from a planet revolving around the star
Betelgeuse and decided to send a signal back, it would take 1400 years to
arrive! If a group of students decides to try this project, they can substitute
some materials. Any metal pipe will do for the main loop. Any kind of metal
screen will make a reflector. To "aim" the antenna, prop it up with the upright
supports. </FONT>
<P><FONT face=Verdana>Many "ghetto blaster" type radios have shortwave bands. An
amateur radio (HAM) Operator could help to interpret the sounds coming out of
the radio. </FONT>
<P><FONT face=Verdana>Trying a project like this fires the imagination. It could
trigger a lifelong interest in electronics and space. There certainly is a
future in it. </FONT>
<P><FONT face=Verdana>For the interested:<BR>Dave Hieserman<BR>Radio Astronomy
for the Astronomer<BR>Tab Books, # 714 </FONT>
<P><FONT face=Verdana>Roy L. Bishop<BR>Observers Handbook<BR>The Royal
Astronomical Society Of Canada<BR>136 Dupont St., Toronto<BR>M5R IV2 </FONT>
<P><FONT face=Verdana>The Young Astronomer<BR>Usborne - Hayes</FONT>
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