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Active Antenna for AM-FM-SW - This simple little circuit can be used for AM, FM,
and Shortwave(SW). On the shortwave band this active antenna is comparable to a 20 to
30 foot wire antenna. It is further more designed to be used on receivers that
use untuned wire antennas, such as inexpensive units and car radios.....(Tony van
Roon's electronic schematic / circuit added 08/09) |
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Active Antenna, easy to build - When fate or nasty neighbors prevent you from
stringing a long-wire receiving antenna, you'll find that this pocket-size antenna
will give the same, or even better, reception. This "Active Antenna"
is cheap to build" and has a range of 1 to 30Mhz at between 14 and 20dB gain....(Tony
van Roon's electronic schematic / circuit added 08/09) |
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Dipole Antenna - A simple dipole antenna can be used for improved FM broadcast
signals. A dipole is basically a length of conductor (wire) split into two portions
and signal is taken off at the split. It has a nominal 3 dB gain over an isotropic
source and is directional, tending...(added 07/07/07) |
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E-field Circuits - If you place the amplifier at the antenna, you avoid all that
cable capacitance but your amplifier must have a correspondingly higher input
impedance to maintain flat gain at the lower frequencies. For a typical 10 pF antenna
(about a meter long) you would want a 100 megohm input impedance to have flat gain
down to 150 Hz! One simple solution is to add some shunt capacitance across the
antenna, eating ... (electronic design added (6/07) |
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Ground Pole Antenna - This Antenna is most widely used all over the world. For
example, when you see a police car it has a transmitter with Ground Pole Antenna The
body of car serves as ground). It accepts load from 50 ohm source and has larger power
output than Half-Wave Dipole Antenna...(added 07/07/07). |
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Half-Wave Dipole Antenna (Open Dipole) - It accepts load from 75 ohm source and
has much smaller power output than Ground Pole Antenna. Use this antenna only when you
don't have GP Antenna. Construction: Two aluminum rods ,each of length "L" in meters
are joined together through an insulator as shown in fig. From center, 75 ohm cable is
feeded just like ordinary TV antenna...(added 07/07/07) |
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J-Pole Antenna - Tuned for 89MHz in the FM broadcast band...(added 07/07/07) |
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Medium Wave Active Antenna - This circuit is designed to amplify the input from a
telescopic whip antenna. The preamplifier is designed to cover the medium waveband
from about 550Khz to 1650Khz. The tuning voltage is supplieb via RV2, a 10k
potentiometer connected to the 12 Volt power supply....(electronic design added 6/07) |
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Pedestrian mobile HF antenna - (design added 6/07) |
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Pi Section Coupler - (electronic circuit added 1/03) |
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Q Multiplying Loop Antenna - (schematic added 9/02) |
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QRP Antenna Tuner - (diagram added 6/03) |
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RF Amplifier for Ferrite Bar Antennas - (electronic circuit added 1/03) |
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Shorty Forty Antenna - Do you have space limitation to put a 40 meter dipole. Try
this Compact 40 meter antenna. . (added 9/04) |
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Simple Dipole Antenna - It is very easy to create a simple 1/2 wave dipole, all
you need is some lengths of wire such as the core of some mains flex or even a
straightened out metal coat hanger, some co-ax cable and a connector for your scanners
antenna input...(added 07/07/07) |
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Small 915 MHz Antenna Beats Monopole - 05/15/03 - EDN-Design Ideas:
A 915-MHz data-acquisition project required a small antenna, but the available
antennas lacked the necessary characteristics: efficiency, compactness—that is,
smaller than a standard 3-in. monopole—with adequate bandwidth, and with amenability
to modeling by inexpensive NEC-2 antenna software.....(design idea added 12/04) |
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Tesla Power Receiver - (circuit added 7/02) |
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The ATL-3 Loop Antenna - All ATL-3 loop windings are centre tapped and balanced
w.r.t. their amplifier/receiver chassis ground, and therefore electric field
interference pick up tends to self cancel. Magnetic noise fields,e.g. televisions and
the electric meter box, or electromagnetically radiated interferences, may be
minimised by loop rotation....(schematic / circuit added 08/08/08) |
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The versatile end-fed wire - A piece of wire of almost any length can be used as
an antenna on the HF bands. However, just because an antenna can be made to work is no
guarantee that it will perform efficiently. This article will initially concentrate on
the half wavelength of wire and its use ....(electronic Schematic added 03/05) |
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TV/Radio Antenna Cable Galvanic Isolator - (electronic schematic added 8/02) |
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Unamplified Four Foot Box Loop - (electronic circuit added 1/03) |
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WIFI CAN Antenna - Got no dough for a commercial WiFi antenna? Looking for an
inexpensive way to increase the range of your wireless network? A tin can waveguide
antenna, or Cantenna, may be just the ticket. This design can be built for under $5
U.S. and reuses a food, juice, or other tin can.... (added 10/05) |
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Windscreen loop aerial - If you do not like the whip antenna on your car, you may
try this alternative circuit. A one-turn loop is installed in the windscreen of the
car, keeping possibly away from the metal structure of the car. This loop is
terminated in a 6.5mm ring core suitable for VHF use...(circuit added 06/07) |
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Wireless Phono Oscillator - A "phono oscillator" is a simple, short-range AM band
transmitter that was typically used to send the signal from a phonograph to a nearby
radio, eliminating the need for an amplifier and speaker. This version uses only one
transistor and... (electronic design added 6/07) |
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Yagi Antenna - To improve signal transmission or reception in specific directions,
basic elements, either vertical or horizontal, can be combined to form arrays. The
most common form is the Yagi-Uda parasitic array commonly referred to as a Yagi array
or beam. It consists of a driven element which is either a simple or folded dipole and
a series of parasitic elements arranged in a plane. The elements are called parasitic
because they are not directly driven by the transmitter but rather absorb energy from
the radiated element and re-radiate it. ….(electronic schematic added 11/08) |
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YAGI UDA Antenna - (circuit added 7/02) |
