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Dutch Antenna and Tower Manufacturers from Slimline Square Triangular Round Towers. Antennas production include Yagi Monoband/Dipole/HF Quad /50MHz and 70MHz Yagi-Quad, VHF-UHF yagi-Quad and Comby antennas VHF/UHF/SHF

Cheap and EZ to build Bi-Directional VHF & HF antennas with gain

RF power meter, dummy load, project

How to make your ham radio system mobilemany ham radio operators carry radios for fun, safety and public service activities. radios for both vhf and hf frequencies can easily be installed in vehicles.

The 60 Watt linear amplifier is simple all solid state circuit using power mosfet IRF840.

QRZCQ.com provides a centralized online platform for amateur radio operators, integrating a global callsign database with DX Cluster functionality. The service features real-time DX spotting, filtering capabilities for specific bands (e.g., 160m, 80m, 40m, 20m, 15m, 10m), and specialized filters for awards like IOTA, SOTA, WWFF, and QRP activity. It also includes a logbook, QSL manager lookup, contest calendar, and various ham radio articles and news feeds, supporting a wide range of operating activities and information retrieval. The platform aggregates data from multiple sources, offering a dynamic view of on-air activity and callsign information. Users can register for free to access additional services, including a personal logbook, buddy lists, and chat features, fostering community interaction among over 198,600 registered users. The DX Cluster displays recent spots with frequency, DX call, spotter, and remarks, covering bands from VLF to VHF. Beyond DX spotting, the site provides resources such as repeater directories, propagation information, and a swapmeet, making it a multi-faceted tool for both casual browsing and serious DXing or contesting. The service also highlights active users, latest news, articles, and videos, keeping the content fresh and relevant.

Live IOTA spots by the dxsummit dx cluster

Monitors the space weather parameters essential for HF radio, including SSN/SFI, Ap/Kp, X-ray/Proton flux, and Auroral activity. IonoProbe downloads near-real time satellite and ground station data, stores information for future use and displays it in a user-friendly way.

Homemade SWR PWR Meter based on Arduino

CB Radio, and 10 meters antennas manufacturer

160m Is it a sloper? or tower drive?

Build your own multi-band mobile ham antenna with a Hamstick

How to calculate "phasing line" lengths that actually work.

Angle Linear has been producing GaAs FET preamplifiers since 1980

Lookup callsigns in locator, or locator of a specified callsign and display in google map

A project with several releases, of the Qkiller or QRM eliminator original project by DK9NL, in italian with schematics, picturs and movies

W1YW QRZ page dedicated to fractal antennas

Article on radiation patterns of small loops, equivalent circuits of loop antenna, small loops as receiving antennas, ferrite loops

All bands HF mobile antennas manufacturer

Military antenna masts

This resource details the conversion of an 80m elevated vertical antenna to include 160m operation, focusing on a relay-switched design over a trap-based approach. It presents specific feedpoint impedance values, such as **32 ohms** for 80m and **14 ohms** for 160m, and discusses the challenges of SWR drift encountered with the prior trap system during RTTY contesting. The article thoroughly explains the design choices for elevated radials, referencing _N6LF QEX data_ to debunk common myths regarding radial length and height, demonstrating that non-resonant radials can offer superior current uniformity. The construction section provides practical insights into building the vertical, including guying strategies, material selection from scrap pipe, and weatherproofing the relay assembly. It highlights the use of a common mode choke for the relay switching line, measuring approximately 5K ohms on both 160m and 80m, and details the L/C matching network's role in achieving a 50-ohm match at the end of a 300-foot RG-11 run. The author describes a precise VNA-based radial trimming procedure, achieving resonant values within a 3 KHz range. The content emphasizes the practical application of theoretical antenna principles, particularly concerning the interaction between the vertical element, cap hats, and the matching network. It offers a candid assessment of component selection, such as using junkbox parts and acknowledging the need for future upgrades to static drain resistors. The article serves as a comprehensive case study for advanced antenna builders tackling multi-band vertical designs.

Freeware windows program by VE3NEA that allow to view and edit the Master Callsign Database file used in many contesting programs, import and export callsigns, auto-download announced DX operations.

Here is a way to ease assembly and balancing of a large antenna. The elements and boom are assembled separately in most cases. Once they are all together set up 2 tripods in the assembly area and put the boom on them.

A simple circuit which will generate a 700 Hz tone into any FM transceiver allowing an amateur to practice CW with another amateur on a 2 meter simplex frequency.

A Bulgarian bazooka antenna project by LZ2ZK

Sioux City Tri-State Area Fire/EMS, Sheriff, Police and Highway Patrol Live Audio Feed. Listen Sioux City IOWA live scanner

Generate QSL cards and labels in your own format. Donationware, windows program by Alpine software officially released for windows XP.

LAPD - Wilshire and Olympic Divisions Live Audio Feed using a Uniden 396T radio scanner

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

open source software designed to control and program the ICOM IC-R8500 receiver

Plans and drawings of common amateur radio antennas, like jpoles, copper cactus, super jpole, omnidirectionals and quads

MSDOS astronomical clock and celestial tracking program with navigation features

Detailed and searchable maps by mapblast

This is a compact three transistor regenerative general coverage receiver with fixed feedback

A complete review of Icom IC-706 review published in 1999 by QST

The antenna is a vertical dipole, around which four parasitic elements are forming a circle.

XPWare offers support for AEA, Kantronics, SCS/Paccomm and Hal controllers. The program also offers full transceiver control for most of todays HF radios and support DX Cluster monitoring. No more supported and developed by author. Now freeware.

Progress in Design of Extremely Short Transmitting Antennas Short and still efficient, how is that possible? By Juergen Schaefer, DL7PE author of the MicroVert antenna concept. The MicroVert introduced in this document is an extremely short and hardly visible short-wave antenna with outstanding radiation properties

Data Management Software for the RadioShack PRO-99 Race Scanner

Slot antennas explained

For radio amateurs seeking compact and efficient antenna solutions, particularly for restricted spaces or noise reduction, HF loop antennas present a viable option. This resource compiles several articles from the ARRL, detailing the theory, design considerations, and practical construction of various loop configurations. Topics include small transmitting loops, receiving loops, and multi-band designs, often emphasizing their performance characteristics such as directivity, bandwidth, and impedance matching. The collected articles provide insights into the comparative performance of different loop geometries, such as circular versus square loops, and discuss the impact of conductor size and tuning methods on efficiency. Practical applications are explored, including their use in portable operations, stealth installations, and urban environments where noise mitigation is critical. The content often includes construction diagrams, parts lists, and performance data derived from modeling or field tests, enabling hams to replicate or adapt the designs for their specific operating conditions.

An interesting article with many technical details on a phased delta loop array for 80 meters band includes pictures of antenna relays

A pictorial guide to the basic ways of desoldering joints

SFFMA 147.000 Repeater audio By KG4LXH

Comprehensive astronomy / space / satellite-tracking package for Microsoft Windows 95/98/Me and Windows NT 4.0/2000/XP

This is a 6 band receive only filter designed to protect your receiver front end and provide 45dB reject at the stop bands. This is a 6-band receive only filter designed to protect your receiver front end and provide 45dB reject at the stop bands. Stop band reject may be limited by the relay isolation. Worse case isolation is at 28 MHz or 35 dB or better. Relay K3/K8 protects the filter during transmit via the PTT line. A 25-50ms delay must be used between transmit and PTT. Do not rely on your radio to provide adequate delay with out using the PTT. You logging software must be set to allow a delay between PTT and time of 1st transmit. This filter will not work with VOX or QSK keying as you will damage the filter.

Working priciple of OSJ and jpole anntennas by PY4ZBZ

Setting up a Raspberry Pi as a SDR Server with RTL-2832U USB dongle

This page will help you answer important questions about antenna selection before you talk to a supplier. After reading this paper, you should be able to better determine the most important parameters you need to know for your antenna selection criteria.

Many antennas function because of common mode currents, rather than working in spite of them. Two popular examples are CFA and EH antennas. Another recent example, appearing in Antennex's compact antenna articles, is a thick stub "vertical" with no counterpoise.