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Dual band J pole operational over the entire 6Mtr band (50 - 54MHz) and the entire 2Mtr band (144 - 148MHz), slightly favouring the upper half of both bands by VK6YSF

Circuit and software to build a beacon keyer, includes downloadable packages.

The slim-jim antenna for 144 MHz

These yagis and groups were designed with YO7.23 from K6STI and checked with EZNEC from W7EL. With a gain of 14/17/20dBd they have a good relation between gain and mechanical problems.

The Buddipole is a hi-tech, take-apart dipole designed for HF portable operations. The antenna uses a multi-band adjustable coil for all bands 40m - 2m.

This DIPLEXER separates 2m from 70cm on the same coax cable, and allows to use 2 antennas over the same cable and permits transmission on one band and simultaneous receiption on the other band by hb9abx

A simple to build Yagi 2 element antenna for 15 or 20 meters band by 9m2mso

The purpose of this page is to capture and document the Yaesu FT-101 series radios during the 1970's

2 Meter Halo Antenna project by Mike Fedler with many detailed pictues and detailes homebrewing instructions so you can build your own

An homebrew project for a 3 elements yagi monoband antenna for the 20 meters by 9M2MSO

The purpose of this web page is to try to investigate the ICOM IC-746PRO Dead TX problem reported by many radio amateurs through out the world; and unfortunately not properly taken care of by ICOM. If you are the owner of either the ICOM IC-746PRO or the IC-7400 you may already have experienced the Dead TX Issue. If not you may sooner or later.

This VHF 145 MHz antenna is easy to build and with no radials. It shows equal gain of 5/8 lambda. It is light weight, you can hang it somewhere (on a tree may be) and work.

A broadband travelling wave dipole for HF bands, whose VSWR is less than 2:1 from 3 to 15 MHz and does not exceed 2.6 to 1 from 2.3 to at least 30 MHz

The document details the optimization and construction of the _Maria Maluca_ antenna, a compact 6-band (20m-6m) directional beam. It presents a comparative analysis of shortwave antenna principles, highlighting the efficiency gains achieved by using an open feeder line and tuner as a resonant unit, contrasting this with the losses associated with traps or capacitive loads in multiband antennas. The resource specifically revisits an older South American 2-element design for 10, 15, and 20 meters, applying modern NEC-based software to develop a six-band version. Performance data is meticulously tabulated, showing impedance, free space gain, gain at 12m height, elevation angle, and front-to-back (F/B) ratio for each band from 20m through 6m. For instance, on 15m, the antenna achieves 5.1 dBd free space gain and 13.72 dB F/B ratio. The construction section provides practical guidance on element assembly using aluminum pipes and hose clamps, detailing the use of a heavy-duty glass fiber reinforced polyamide rod for electrical separation and bending strength. It also specifies the use of 450-ohm _Wireman_ line CQ 552 for the transmission line. The document includes diagrams for rod fixing, an air-wound balun, and a vertical elevation diagram for the 15m band, illustrating its DX qualification. It also discusses the antenna's suitability for portable and expedition operations, noting its compact transport dimensions (max 1.50m length, 12 lb weight) and quick assembly time (under 15 minutes). The author, Dipl.Ing. Helmut Oeller, DC6NY, is identified as a source for material kits.

The Chameleon V1 HF Multiband Antenna is a mobile antenna that can also be used as portable. Lightweight mil whip antenna system with 10 BANDS capability 6m, 10m, 12m, 15m, 17m, 20m, 30m, 40m, 60m & 80m.

144 and 432 Mhz GS35b High Power Amplifier

A 40 ft vertical dipole antenna that can cover HF Bands from 80 to 10 meters winding a dipole in a 12m HD telescoping fiberglass pole

This 2 meter 3 element cubical quad antenna is small, light weight and portable. A backpack antenna that is easy to put together in just minutes and parts store inside the boom making it ready for travel or storage.

VU2RAR basic VHF power amplifier suitable for 144-146 Mhz output power can vary from 3 to 25 Watts.

An homemade portable vertical antenna with a trap near the mid point of the main element. The trap is made with 42mm diameter PVC pipe with 9 turns of wire on it

The Discovery series of amplifiers are designed and built in the UK by Linear Amp UK Ltd, one of the world's leading amplifier manufacturers, specializing in high power RF tube amplifiers. The amplifiers use large GS31 or GS35 ceramic triode tubes. Band coverage 6m, 2m and 70 cms

Presents the design and construction of the OK2FJ Bigatas, a portable, automatically tuned vertical antenna covering 80 through 10 meters. It details two distinct control systems: one utilizing BCD band data from Yaesu FT-857/897 transceivers, and another employing voltage level sensing for the Yaesu FT-817. The resource provides specific instructions for building the antenna's radiating element, loading coil with switchable taps, and the control circuitry, emphasizing the use of readily available components. The article outlines the physical construction of the antenna, including the use of duralumin tubes for the radiator and a PVC tube for the coil form. It specifies coil winding details, tap points, and the integration of radial wires for ground plane operation. The control electronics section provides schematics and component lists for both the BCD decoder (using a 74LS42 IC) and the voltage comparator (using an _LM3914_ bargraph driver), enabling rapid, automatic band switching without the minute-long tuning delays common in other systems. Crucially, the antenna achieves rapid band changes, with typical SWR values centered on common operating segments, such as **3.7 MHz** for 80m SSB. It also discusses modifications for CW operation on 80m and the trade-offs between antenna efficiency and full-range automatic tuning on higher HF bands, where manual adjustment of radiator length is suggested for optimal performance on 15m, 12m, and 10m. The resource includes construction photos and a discussion of cable requirements for reliable operation.

Free Donwload of the PDF file of ITU and CQ zones of the world, made available by Icom America

MMMonVHF maintains the data for 6m, 2m, 70cm and 23cm bands in collaboration to LA0BY. This site allow display of a beacon map and latest beacon spots.

Put up the longest dipole you can fit, feed it with open wire line, connect it to the balanced output of your tuner and poof! Instant multiband antenna. Is life really that simple?

The diagram below shows the basic arrangement of the 2m Half-Wave version of the antenna. A 6m diagram is available too.

Antenna was designed for SO-50 satellite operation but can be used for any VHF/UHF activity. It's a mix of a Moxon Antenna and a Yagi antenna. It has gains 4 dBd on 2m and 6.5 dBd on 70cm bands and it is fed via single 50 Ohm cable.

The ZS6BKW wire antenna, a variant of the G5RV, utilizes a specific 13m (42.6 ft) length of 450-ohm window line as its matching section, feeding a 28.5m (93.5 ft) flat-top element. This design aims for lower SWR on 40m, 20m, 17m, 12m, and 10m compared to a standard G5RV, often achieving SWR values below 1.5:1 on these bands without an antenna tuner. The feedpoint impedance transformation provided by the window line allows for direct connection to 50-ohm coax on multiple bands. F4FHH's experience involved constructing the ZS6BKW and evaluating its performance against an _OCF dipole_ (Off-Center Fed) on various HF frequencies. The article includes observations on SWR readings and operational effectiveness, highlighting the ZS6BKW's suitability for multi-band operation. The antenna's overall length, including the flat-top and window line, is approximately **41.5 meters** (136 feet), making it a significant wire antenna for fixed station use. Comparative analysis with the OCF dipole provided practical insights into the ZS6BKW's advantages and limitations, particularly concerning bandwidth and tuner requirements.

An interesting article on building a 4 elements yagi antenna with gamma match for the 2 meter band. This article include two videos demonstrating assembling procedure by KG0ZZ

A simple beam antenna offering good performances on 3 bands by 9m2mso

A basic drawing of a 2 meter quad antenna for 144 MHz

The purpose of this page is to show you how you can access a DX Cluster via the Internet. There are many software applications available, some are free some are not. Excellent page from OZ2M

VU2VWN project to homebrew a CW for 40 meters band

A site exclusively meant for the novice. Find all the information necessary to become an amateur radio operator! More India specific information.

An RF power supply for 144 MHz schematics and instructions

Add-in module to Microsoft Excel, contains a set of radio amateur relevant special functions: DistSphericLocator(Loc1; Loc2) Calculates the spheric earth model distance between two locators [km] DirSphericLocator(Loc1; Loc2) Calculates the spheric earth model direction from Loc1 to Loc2

This design was adapted from an article in the ARRL Handbook and built with simplicity and duplicity in mind. This antenna is a vast improvement over a standard dipole with a forward gain of around 8db with a front to back ratio of 10db.

CW paddle made with a steak knife some simple hardware and a stainless steel fork

Presents a detailed construction guide for a **Quadrifilar Helix Antenna** (QHA) optimized for 137 MHz, specifically for receiving weather satellite transmissions. The resource outlines the author's experience building previous QHA designs, highlighting challenges with tuning and nulls, and then focuses on a refined design by John Boyer, documented by Steve Blackmore, which proved easier to build and yielded superior reception. The guide provides precise element dimensions, including 1.5m of 32mm PVC pipe for the mast and 8mm soft copper tubing for the helix elements. It specifies lengths for horizontal tubes (190mm, 90mm) and helix elements (903mm, 1002mm), along with instructions for drilling, assembly, and forming a **balun** by wrapping RG58 coax around the mast. The text emphasizes critical steps like ensuring elements are square and twisting in the correct direction to avoid phase issues. It includes references to original QST articles by Buck Ruperto (W3KH) and the WxSat program for decoding satellite transmissions, contextualizing the antenna's purpose. The article concludes with a sample NOAA 12 image from September 1998, demonstrating the antenna's reception capabilities.

This purpose of this page is to give a brief description of a 70 MHz transverter that has been published in the Danish amateur radio magazine "OZ"

A simple quarter-wave length vertical for 40m band using a 12 m spiderpole

Free format input, User selectable usage of reports, counters for DXCCs, WWL, DOK/UK Counties/CQ/ITU/States/Provinces and more

Comparison of several UHF antennas by DF9CY

Wire beam antenna for the bands 6m, 10m, 12m, 15m, 17m and 20m

A simple 7 bands off-center dipole wire antenna designed to work on 80 meters band and that can cover also 40m 30m 20m 15m 12m 10m with acceptable SWR

VU3NSH article on high current universal supply for rigs

A five element quad antenna for 144 MHz DIY Project. This 2 Meter 5 Element Quad antenna was modeled using EZNEC, with a boom from a UHF TV antenna and CPVC pipe for spreaders. Constructed for 146MHz, it exhibits a gain of 10.7dB and an impedance of 75 ohms. Real-world results surpass the HT antenna, reaching over 20 repeaters up to 75 miles away. The design, costing around $10, employs simple tools for assembly.

G0KYA's Amateur Radio Blog, make a 2m Slim Jim antenna out of 300 Ohm ribbon cable.

This HALO design is not ground dependent and can be mounted atop a section of PVC.

An easy mod to make the 1st IF of the Icom IC-7600 accessible and connect to a cheap RTL SDR dongle by VE4NSA