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This Z-Match is a link coupled all-band tuner. Two all band tank circuits cover 3-14mhz and 14-30mhz. The tank output links are selected with a very heavy duty SPDT rotary switch.

The GM3VLB Poor Man's Antenna Analyser

Demonstrates the construction and implementation of a **two-element phased vertical array** for 40 meters, utilizing _Christman phasing_ techniques. The author, W4NFR, details the process from building individual 1/4-wave aluminum verticals to integrating them into a phased system. The resource covers antenna spacing of 32 feet, elevated radial design, and the critical steps for tuning each vertical to achieve a 1.1:1 SWR before combining them. It also provides insights into calculating precise coax lengths for feedlines and the phasing delay line, emphasizing the use of an MFJ-269 Antenna Analyzer for verification. The finished system exhibits good front-to-back nulls, with an overall SWR ranging from 1.6:1 to 2.2:1, which is managed by an antenna tuner. The project includes detailed photos of the relay box, showing 12 VDC relays capable of handling 5KV, and the control box in the shack for switching between three different antenna pattern configurations. Static bleed-off chokes are incorporated for protection, and the construction emphasizes robust weatherproofing for outdoor elements.

A project of a small antenna, just 50 cm for the 7 MHz band. An EH Antenna plan for the 40 meters band

Carry a small stock of new and reconditioned parts for both rotators and control boxes for the following makes: CDE/HYGAIN , YAESU , STOLLE.

The 2BCX Slim Jim by F.C. JUDD, G2BCX.

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 monster magnetic loop antenna for 160 meters band. This Magnetic loop is optimized for 1840 Khz + 50 Khz. PDF Article published on La Radiospecola 10.22

Two meter band antenna

A wire dipole antenna for 80 meters band

Two Delta-Loops in phase. The purpose of this article is to propose an antenna with a high gain, a high efficiency and a very low price that is easy to build for any frequency.

This calculator is designed to give the vertical length of a quarter-wave ground plane antenna, and the length of each of the four radials for the selected frequency you have entered

Understanding Amateur Radio NVIS Antennas and Propagation

G0KYA review of the EH antenna for 20 meters band

VE3CVG 222 MHz (1.25m) 6 element plumber's delight yagi antenna

Here is a review of the 40 and 80 meter band Double Bazooka antennas as used on the HF shortwave bands.

A fractional bandwidth of up to 30:1 characterizes spiral antennas, making them highly effective across a very wide frequency range, often from 1 GHz to 30 GHz. The resource details two primary types: the **Log-Periodic Spiral Antenna** and the **Archimedean Spiral Antenna**, defining each with specific polar functions and illustrating their planar configurations. It explains that spiral antennas are typically circularly polarized, with a Half-Power Beamwidth (HPBW) of approximately 70-90 degrees, and a peak radiation direction perpendicular to the spiral plane. The content elaborates on critical design parameters affecting radiation, including the total length (outer radius) for lowest frequency, the flare rate ('a' constant) for optimal radiation versus capacitive behavior, the feed structure (often an infinite balun) for high-frequency operation, and the number of turns (typically 1.5 to 3 turns). It also discusses the theoretical impedance of 188 Ohms for Log-Periodic spirals, derived from Babinet's Principle, noting actual impedances are often 100-150 Ohms. The article presents a simple construction method for an Archimedean spiral, demonstrating VSWR and efficiency measurements. Measurements from a constructed spiral antenna show a VSWR that is fairly constant across the band, albeit with a mismatch loss of about 3 dB. The antenna efficiency remains around -5 dB (31.6%) across its operating range, indicating a decent wideband radiator despite opportunities for optimization.

The design and feeding of driven elements for VHF/UHF Yagi antennas , modeling, observations and some case studies by Graham Daubney F/G8MBI

A 2m 70cm Dual Band J-Pole antenna for 35 USD. An excellent performing J-Pole type antenna, constructed from readily available materials.

The Gizmotchy high performance horizontal and vertical beam antenna for 2/6/10/11 meter bands

Useful tips for the use of automatic ATUs

This page allows you to calculate in the most accurate way high-Q inductor coils.

The information in this article has come from many amateur sources, the most notable was from WA6TEY (sk 1985) Ray Frost, who was a pioneer of VHF Quad designs and one of the best Southern California Transmitter Hunters. Ray built hundreds two meter quads in single and paired configurations as well as his famous mobile radio direction finding quad.

Green that aluminum into something useful right in your own backyard by WB2CQM

The Remote Control Antenna Switch consists of two circuit boards. The control unit and the remotely controlled switch

A Wire resonant loop antenna for 160 meters band article by N4KC

Planning and modeling a special L antenna for Top Band

Antenna dimension, diagram and simulation of the ZX Antennen ZX 6-6 Yagi for VHF UHF by DF9CY

A page by 9A7PJT dedicated to HB9CV yagi antennas includes link to the HB9CV calculator program and some interesting plans

Delta 160-meter receiving antenna used at FO0AAA

A DIY guide to build your own compact multiband HF antenna based on the G3TXQ version using a 1:4 balun. This article includes the full part list and instructions to assembly, including the center plate.

Benefits in implementing a remote antenna switching system and a sample remote antenna switch project

An Unorthodox Antenna, originally by W3AWH is considered a multi-band antenna suitable for fixed location use and as an easily deployable portable antenna for events such as Field Days.

The N3UJJ multi band cage dipole antenna project thay can fit a small property

This calculator is designed to give the horizontal length of a particular dipole including Tees, antenna, or one side of it, for the frequency chosen. Enter the desired frequency and select the desired calculation from the drop box

A moxon antenna project made with wires and fiberglass poles

This antenna is intended for the 20-meter Band. There are two Voltage Fed Helical Dipoles, made with 2 slinky that fed with phase shift in 90 degree

Measurements for building a full wave loop using wire

An home made slim jim antenna for 2 meters band by VU2TQC

2 Meter Slim Jim Antenna Using 300 Ohm Twinlead

An efficient monoband end-fed half wave for 10m, 20m or any other HF band

The essentials of the parabolic reflector or dish antenna and its theory and design for high performance applications such as satellite transmission and reception as well as microwave links.

Demonstrates the adaptation and construction of a 7-element DK7ZB Yagi antenna for the 4-meter band (70 MHz), utilizing components from a defunct 2-meter CUE DEE Yagi. The resource details the modifications made to the original DK7ZB design to fit the shorter CUE DEE boom length, specifically adjusting element lengths for 6mm rod elements while reusing existing mounting holes for the reflector and last director. It provides precise element lengths for the reflector, dipole (12mm aluminum tube), and five directors, along with a note on cutting elements for transport. The article includes a 4NEC2 simulation file for performance analysis and an SWR plot, confirming the antenna's electrical characteristics. It also specifies the calculation for the quarter-wavelength matching cable using SAT752F coaxial cable, resulting in a 909mm length. Practical application is shown with the finished antenna in operation at JO20XC, listing several activated Maidenhead squares such as JO56PA and JP40KS, validating its effectiveness for portable 70 MHz operations.

This PDF document details the construction of a **70 MHz** Big Wheel antenna, a horizontally polarized omnidirectional array. The design utilizes three full-wave loops, each approximately **2160 mm** in diameter, arranged in a triangular configuration. The resource provides mechanical dimensions for the antenna elements and a comprehensive bill of materials, specifying component quantities and types, such as M8 stainless steel bolts, 15x15x1.5 mm square aluminum tubing for spacers, and 8 mm aluminum rod for the arcs. The central hub is constructed from two 160x160x8 mm aluminum plates, with four 40 mm long polyamide insulators supporting the radiating elements. The feed system incorporates a 50 mm diameter aluminum pipe for mounting and a matching stub constructed from a 120x20x2 mm aluminum sheet, connected via M8x10 mm bolts. The resource includes a diagram illustrating the mechanical dimensions and assembly points, including the N-connector fixing point and the center conductor attachment. The project was published on May 25, 2011, by Peter OE5MPL and Rudi OE5VRL. DXZone Focus: PDF | 70 MHz Big Wheel | Mechanical Dimensions | **2160 mm** loop diameter

Antenna designs that K5TR have collected from various sources.

A Home made QRP tuner for 10-40 meters

Antennas for restricted lots, apartments and indoor antennas by VK3YE

Understanding Baluns. This article explores some simple antenna system configurations and the effect of key system components, connections and dimensions on feed line common mode current.

A New Way to build a 1/4 Wave Ground Plane Antenna

Using patch antenna for amateur radio reception of the 13cm band with a sample 2.4 GHz LHCP patch antenna by K3TZ