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DeadlyEyes
| | Posted on Monday, June 24, 2002 - 10:22 pm: | 
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All thru these posts the question is asked, "What is the best antenna?"
First lets define the purose of any antenna. The simple purpose of any antenna is to transmit a radio signal from point "A", your station, to point "B", a station somewhere else. If the station you are attempting to contact is within 'Line of Sight' aka not skip then any old kind of antenna will work. After all if you could sit on your antenna and see the reciving antenna you do not need any sophisticated gear.
HOWEVER, if the station you are trying to reach is a thousand miles away then you need to think about several things. We all know that 'Skip' is when the signal bounces in the atmosphere. But the angle that the signal leaves your antenna determines the amount of each bounce and the first one in particular. Draw a big circle and draw a smaller circle within the big circle. The little circle is the earth and the big circle is the atmosphere that reflects the signal. If you send a radio signal parallel to the earth it will go strate out, hit the reflecting layer in the atmospher and bounc back with an equal angle down--one huge bounce. BUT if if your signal leave at an almost vertical the signal (strate up) will hit the reflecting layer much much sooner and come down much much shorter. The signal bounces off the earth back up at a the same sharp angle and back at a sharp angle--again again and again. The more you bounce the more umph is taken away from your signal. Any station inbetween the points of contact with the earth may hear the signal but it will be faint. If the signal falls directly on your station then the signal will be much stronger.
Now to antennas....
Which antenna is the best. There is no such thing as a single best antenna. Sometimes a good vertical/ground plane will outperform a beam because the signal happens to bounce directly on top of the receiving station. Sometimes the beam will do a better job because its signal is transmtted at a better angle. A good antenna system is not one antena. A good antenna system is a system of antennas/plural of different types.
Our good friends at coppers offers a fine line of antennas. Here is what I would put up as a lineup of antennas for the 10 meter/near CB ham band. First thing to go up is a utility gain vertical for general listening and detecting signals not strong enough to hear off the back of the beams/plural and a good antenna to use for local chit chat. The second antenna to go up would be a nice mid priced utlity gain beam like a PDLII or a three element beam. This gives me the mid range and a normal/daily use beam. The third antenna if I had the space (and money left) would be a Lazer 500 or some other big gun antenna for the big reach where the PDL is insufficient to bang thru a pileup and to hear those weak stations.
Sunspots and magnatic storms of course both help and hurt your abiltiy to transmit a good signal as well. The time of day or night is also important.
So if you have two or three good antennas at your disposal you just flip back and forth to find the one that is working the best. Sometimes it will be the beam. Sometimes it will be the stick. Whichever one is receiving the signal the strongest start with that one.
So just flip thru our good friends at coppers and say howdy to the sales staff. Just looking at their lineup of antennas they have both verticals and beams. And a nice selection at that.
In closing remember one thing given the choice between power and a good antenna always go with a good antenna system first. You cannot talk to people you cannot hear.
Good luck..
DE
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PsychoRadio
| | Posted on Tuesday, June 25, 2002 - 3:59 am: |
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Hey nice post there deadeys. theres been alot of talk about beams lately ad what not. Is there a set up out there that is a beam, which can turn and have differnt angles, but with an omni directiona off the top center of the beam or mast. That way you get the best of both worlds. |
bruce
| | Posted on Tuesday, June 25, 2002 - 7:17 am: |
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Now THIS is a antenna
http://web.wt.net/~w5un/qsl.jpg
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Biged
| | Posted on Tuesday, June 25, 2002 - 10:12 am: |
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Bruce,
I have a magazine with that guys antenna on the front. It has a whole article about it inside on how it was made and how much money he has invested in it. He accually has a truck frame bolted to the bottom of it to rotate it and a homemade icream maker motor on the truck frame for the power. He has approx $10,000 into it and most of his material was salvaged from junkyards. I'll back you up, THIS IS AN ANTENNA!! |
Taz
| | Posted on Tuesday, June 25, 2002 - 3:40 pm: |
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im supriesd that the power is still there at the antenna. how did he make the coax feed to it? |
bruce
| | Posted on Tuesday, June 25, 2002 - 7:13 pm: |
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Now here is a way he could USE that monster ant!
Space Bulletin 006 ARLS006
From ARRL Headquarters
Newington, CT June 25, 2002
To all radio amateurs
SB SPACE ARL ARLS006
ARLS006 AMSAT-OSCAR 7 returns to life
The AMSAT-OSCAR 7 satellite suddenly has come back to life after being dormant for more than 20 years. First heard June 21 by Pat
Gowan, G3IOR, AO-7 subsequently has been monitored and used by several other amateurs. AO-7 was launched November 15, 1974. It
remained operational for more than six years before succumbing to battery failure in 1981.
''I'm blown away,'' was the reaction of AO-7 Project Manager Jan King, W3GEY. ''So, this old war horse of a spacecraft seems to have come
back from the dead if only for a few moments.''
Exclaimed satellite enthusiast and AMSAT Vice President for User Services Bruce Paige, KK5DO, ''This is really awesome.'' Paige said
the latest turn of events makes AO-7 is the oldest amateur satellite that's still working. AMSAT-NA has now listed AO-7 as
''semi-operational.'' |
Biged
| | Posted on Tuesday, June 25, 2002 - 8:11 pm: |
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Taz,
The boom is made from rohn-25 tower sections. 155 feet long.It rotates around a 358 foot track. It takes about 15 minutes to rotate all the way around. The coax used to connect and phase all three Yagi antennas is aluminum jacketed 75 ohm cable tv hard line. The array is capable of boosting power by 30 db(referenced to a simple dipole antenna). In other words with 1500 watts delivered to the array, the effective radiated power is nearly 1.5 million watts. The beam is sharply focused, with a 3-db beamwidth of 1 3/4 degrees in the E plane and about 6 degrees in the H plane. Now all of this was copied out of QST magazine verbatem, so I dont want any arguments about the power that this thing can produce. LOL !!! Anyway, all the technical stuff just goes over my head. Think about it, I still use an Antron 99...Eddie |
PsychoRadio
| | Posted on Tuesday, June 25, 2002 - 8:13 pm: |
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Looks like a good clothes line. |
DeadlyEyes
| | Posted on Tuesday, June 25, 2002 - 9:38 pm: |
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Re Crash Boom.....
If I am wrong please feel free to correct me, I seem to remember reading somewhere that particular antenna system was destroyed by a wind storm (I think) just shortly after that picture was taken. |
Biged
| | Posted on Tuesday, June 25, 2002 - 11:26 pm: |
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I am not sure. The date on this issue is September 2000 |
bruce
| | Posted on Wednesday, June 26, 2002 - 12:12 am: |
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it was rebuilt even BIGGER ! |
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