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W3DZZ trapped multi-band antenna, exposed in this practical wireless article

Simple, easy to build, low cost, compact, multiband By Robert Wilson, AL7KK

The problem with making your own trapped HF antennas is usually getting the coaxial traps tuned to frequency.

A project of a semi vertical trap antenna that can be tuned for 7 bands

A simple TRAP-dipole project for 20 and 40m bands includes EZNec simulations

Over 1,000 stations in approximately 60 countries were worked using this modified twin-lead folded dipole, demonstrating its effectiveness with just 4 watts on 20 meters. This design, adapted from an ARRL Handbook concept, eliminates the shorting strap found in traditional folded dipoles, simplifying construction while maintaining performance. It utilizes readily available 300-ohm TV antenna feeder ribbon, making it a cost-effective solution for radio amateurs. The antenna's robust construction allows it to handle up to 100 watts without issues, even without a **balun**. The inclusion of a variable trimmer capacitor at the stub provides flexibility for tuning across different frequencies within a band, a practical feature for operators using transceivers like the Icom 735. Formulas are provided to calculate the precise dimensions for any desired operating frequency, enabling customization for various **HF bands**.

Article published on Practical Wireless about the W3DZZ multiband trapped dipole antenna made available by GM0ONX

How to operate on 10 and 20 meters in limited space with this trapped dipole.

A trapped dipole antenna based on the orignal W3DZZ antenna design resonating on 80 40 20 15 10 meters

Tips and tricks on homebrewing your own Coax traps by ON7EQ

An easy to make, cheap, no trap, multiband wire vertical antenna by PA1M

An HF multiband trapped antenna in french

An homemade portable trapped dipole antenna for 40 and 80 meters band with an optional extension for the 20 meters.

Analysis of an antenna trap where a coil is formed of a length of coax cable, the outer conductor of one coax end is tied to the inner conductor of the other coax end, and the remaining connections form the terminals for the trap.

Tips to homebrew your own HF traps using aluminium wire and doorknob capacitor

Wide bandwidth Trapped Verticals and rotary dipoles, baluns, 40m/80m wire dipoles and accessories from Australia.

Notes and details on repairing Traps on Cushcraft A3S

This project details the construction of a **full-sized 40-meter vertical antenna**, born from a renewed interest in 7 MHz operation and a desire for improved effectiveness over simple dipoles. The author, K5DKZ, initially focused on VHF experimentation, which provided an inventory of aluminum tubing and fiberglass spreaders for this endeavor. Before this vertical, K5DKZ utilized an 80/40 meter inverted-vee trap dipole and a 40-meter broadband dipole, but now primarily uses a pair of full-sized, phased, quarter-wave verticals spaced 35 feet apart for serious 40-meter work. The construction involves a base-heavy design for stability, using a 44.5-inch section of 1-1/4 inch steel TV mast driven into 1-3/8 inch aluminum tubing, insulated by a 105-inch section of Schedule 40 PVC pipe. The assembly reaches 31 feet, close to the 32 feet required for a quarter-wavelength on 40 meters, with fine-tuning achieved by winding wire onto a fiberglass spreader. The design is explicitly presented as a foundation for a two-element 40-meter Yagi beam, outlining modifications like substituting aluminum for steel in the base and using an inductive hairpin match for the driven element. The article also discusses tuning considerations for a large 40-meter beam, noting the 100 to 200 kHz upward frequency shift when raised, and suggesting methods for installation on a tower. The author emphasizes the cost-effectiveness and good performance of the monopole approach, especially when multiple verticals are needed.

A 4-Band vertical antenna that needs NO tuner, NO traps. Implement an LC matched on 4 bands with relay switching.

Specialist in the design and supply of Radio Communications Equipment and Systems. West Sussex England. Antennas, traps and baluns inline isolators, Outbacker Antennas, Mobile Mounts and Accessories

A Co-ax Trap Dipole For 40, 30 and 20 Meters or at last that was the intention

A trap on the coaxial cable, also known as choke, helps to eliminate the sneaking of the reflected RF- energy to the shack. The trap can be made from the coaxial cable that feeds the antenna

A small sized and very cheap antenna project that allow you to work on WARC bands with a total gain very close to the dipole in both bands. On 12 meters is a normal dipole, while on 17 is a trapped dipole. Article in Italian

A multiband coax trapped dipole for 10-80 meters bands by DF1PU

Tuning Antenna Traps without a Grid Dip Oscillator, using a bit of initiative and some standard equipment a ham should have in the shack.

Tips on winding wire coils used as inductive loads, traps, band-pass filters, are implemented in a number of amateur radio projects especially antenna projects

The resource details the construction of a multiband trap-style Inverted-V antenna designed for operation on 3.5 MHz, 7 MHz, 14 MHz, 21 MHz, and 28 MHz. It presents specific winding data for the traps, including the number of turns, wire gauge, and coil former dimensions, crucial for achieving resonance on the target bands. The document provides a parts list and a diagram illustrating the antenna's physical layout and trap placement. It outlines the process for building the traps using PVC pipe formers and specifies the required capacitor values for each trap. The design emphasizes a practical approach to achieving multiband operation with a single feedline, a common goal for HF operators with limited space. The document includes a table with antenna segment lengths for each band, allowing for precise replication of the design. It also offers insights into tuning and adjustment, ensuring the antenna performs optimally across the designated amateur radio bands.

Diamond W8010 Multiband Dipole Modifications

Distributor of ESD, kapton tapes, high temperature tapes, esd wrist straps, ionizers, ground cords, grounding devices, ESD gloves, esd finger cots, esd workstations, esd rubber bands, esd binders, esd bags, anti static glove, esd rubber bands, no clean solder paste, water soluble solder paste, finger cots, esd mats

A multiband trapped end-fed antenna can cover 20 30 40m bands. An option for portable sota operations were weight end simplicity are essential

About Coax Traps, NC4FB examine the operation of coax traps through modeling.

An easy to build dipole for 21 and 14 MHz with traps made by two T50-6 toroids cores mounted on a simple PCB foil

An easy to build and extremely high performance antenna, works perfectly on all HF bands 3.5-28 MHz with some compromises, it is basically an half wave dipole for 40-80 meters, an LC circuit or trap 40 meters allows you to use a single radiating element.

How to home made antenna traps with material you can easily find, and how to properly tune it.

Tuning HF Coaxial Antenna Traps

Multiband Trap Dipole, portable short antennas, accessories and kits by DG1DBM

Using Chokes and Traps: how to make them, how they work.

A trapped multi band end-fed-half-wave antenna for 40/30/20/17/15m.

Full article on how to build a home-made wire dipole antenna for 40 and 80 meters band. Article is fully in italian, as it was published on ARI RadioRivista, but is plenty of self explaining pictures that will guide you on homebrewing this trapped dipole antenna for the lower amateur radio bands.

This antenna is an omnidirectional and multiband and it is well suited for DX enthusiasts with limited space. Each of the parallel circuits (trap) behaves like an isolator on its resonant frequency.

A group for sharing, learning or presenting practical ideas and field experience for Ultra portable ham radio digital comm

A trap antenna dipole covering two differen bands made reusing an old 160/80m inverted vee antenna.

Diamond W8010 Multiband Dipole Modifications

When you get out of the car, strap your D710 to your old HT and continue APRS inside

The problem with making your own trapped HF antennas is usually getting the coaxial traps tuned to frequency. This article explains a method using a RF signal generator at +10dBm output into the coaxial trap.

An 20 30 40 meters trapped dipole antenna plan for sota and portable operations.

This antenna is a classical antenna working on 7,10,14,18,50 MHz is implemented with three traps for 30, 17 and 6 meters

Top Loaded Vertical Antenna 3,5 MHz 80m and a 14 MHz Trap for the 20m band. The weight of this portable vertical antenna is less than 1 kg, including the ground network. The weight of the telescopic fiberglass fishing rod is another 1kg. The rod expands from 1.5 meters to 8 meters.

A document that will guide you on Coaxial-Cable trap optimization process to gain on global antenna performance and on increasing effective bandwidth.

A 3 band dipole antenna for 40-80-160 meter bands, It's made with easily available materials and is designed for inverted V mounting. The antenna is shortened for these bands, but still manages to make contacts in 80m and 160m with stations in Canada and the USA. The construction details are provided, including the dimensions of the antenna elements and the traps. The antenna is easy to build and provides good performance in all three bands. In Italian.