Vertical Antennas For Ham Radio
Vertical Antennas For Ham Radio
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Solarcon I-MAX 2000 CB/Ham Radio Base Station Vertical Antenna - 24' $99.18 Solarcon IMAX-2000 24ft Omni-Directional Fiberglass Base Station Antenna 5000 Watts.... |
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MAGNETIC Mobile ANTENNA Ham Radio 2 Meter / 70 cm 144 - 148 & 440 - 470 MHz $22.95 Magnetic Antenna with approx. 12ft Coax cable & pl-259 Connector attached. Transmits 144-148 / 430-450Mhz Dual band. Can be ued with Mobiles, or with Optional adapter cable for Handhelds too!... |
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MIRROR MOUNT 3 way Aluminum with Stud for CB / Ham Radio Antenna Bracket - Workman RV1 $2.95 ... |
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40 Meter Mobile Ham Radio Stick Antenna $21.99 40 Meter Amateur band mobile ham stick type 3/8-24 antenna.... |
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Vertical Antenna Classics (Radio amateur's library) $10.20 ... |
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The Arrl Antenna Book (19th Ed./Bk&CD-ROM) $22.97 All the information you need to design your own complete antenna system.Since the first edition in September 1939, radio amateurs and professional engineers have turned to The ARRL Antenna Book as THE source of current antenna theory and a wealth of practical how-to construction projects. Use this book to discover even the most basic antenna designs-- wire and loop antennas, verticals, and Yagis--... |
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Understanding, Building, and Using Baluns and Ununs $19.95 The successor to the popular and authoritative Baluns and Ununs. Great deal of new tutorial material, also includes new designs not in his previous book, and crystal clear explanations of how and why they work... |
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FireStik TM3 Tunable tip Mach-10 10-Meter Ham Radio Antenna $19.38 ... |
Ham Radio Dipole questions?
Is there such thing as a full wave dipole?
Why a half wave dipole is more often used? Is it more efficient?
What about vertical antennas? Can i construct one λ/2 λ/4 or λ/8? Will it be efficient for Rx Tx ?
Whats the difference between radials and counterpoise ?
Thats all!
it was discovered in the beginning of radio that the 1/4 wave antenna was the most efficient. If you look at the voltage and current curves you can see why this is.
A dipole is two quarter wave radials, also called a HERTZ antenna.
Radials and counterpoise are the same thing.
Think of a hertz antenna in free space. You have one side of the feed point to one element, the other side of the feed point to the radials, counterpoise. Next, using a Smith Chart, you can plot the voltage and current highs and lows (NULLS).
The radials as well as the radiating element needs to be resonate.
I would suggest a couple books.... one by LB Cebik and the other ANTENNAS by the ARRL.
You should be able to find both at www.arrl.org
additional:
contrary to the mis information you are receiving here... a dipole is a 75 ohm feed, the Z is adjusted by the angle of the feed. 75 ohms is not a bad match! In fact, it is very good.
A dipole can be mounted up and down or left and right. The only difference is the radiation polarization. Horizontal is for distance, the pattern hugs the ground (sky wave does not care). If your target is mobile, most mobile stations are vertical, so the transmitting antenna is also vertical - there are exceptions (one of my HF mobile antennas is a folded over NVIS antenna using mil surplus antenna pieces). Shunt fed towers are vertical polarized, but again, skywave propagation does not care how your antenna is situated.
and in a last resort, www.w5yi.org