Search results

An article describing a homemade 40m wire OCF Dipole

Two different ways to create autotransformer for end fed half wave wire antennas, by using ferrite or air core.

Gold Line, a manufacturer, provides a range of professional audio test and analysis equipment, including specific products like the **ZM1 Impedance Meter**, which is relevant for amateur radio operators needing to characterize antenna systems. The site also lists various noise sources and microphones, such as the TEF04 Mic, indicating a focus on audio signal integrity and measurement. The resource details contact information for repairs, calibration, quotations for specific products like the ZM1 and ZM1P, and technical support, with distinct email addresses and phone numbers provided for each function. This structured contact approach facilitates direct engagement with the appropriate department for specific inquiries. Operational changes effective March 1, 2019, are noted, directing users to VLDESIGN for repair and calibration, and to Partha Chen for ZM1/ZM1P quotations. Louis Pittsley is designated for technical support, with a general inquiry phone number also available, outlining the company's support infrastructure.

Multi-frequency radio interferometers

Java based interface to dxWorld.com for Linux by K0EMT

Evaluation of various microphones on-air using an Icom IC-7700 by VA7JW

A well documented Heathkit SB-200 restoration project by NT1K

The antenna in this project is a modification of the techniques used to design a multiband fan type dipole with little or no tuning involved having a total space of 105 feet

A tutorial on using RF frequency counter, how a digital frequency counter works, includes frequency counter specifications and best practices in setting counter accuracy and resolution

Yaesu FL-110 160-10m HF linear ampflifier as ideal power amp for the FT-817 by N2CHK

Abbreviations used for words on CW, ranging from commonly used abbreviations like B4 for Before or TU for Thank You to very obscure abbreviations known only to the one using them

UV-3R Review at G4ILO Blog with long textual review, pictures and some sound files

remoteAudio is an multi platform Audio streaming application for Amateur Radio purposes. The most typical use case for this software is the remote operation of an amateur radio station. remoteAudio supports multiple users and multiple audio sources. At any time multiple clients can listen simultaneously on the same radio, although remoteAudio only allows one user to transmit.

Documents the construction of a **VHF/UHF** antenna addition for the Buddipole HF antenna system, leveraging the existing Versa-Tee component. The project details the fabrication of a custom antenna mount from angle aluminum, including specific drilling and tapping for 3/16"-24 bolts, and the creation of radials from Simpson Strong Tie Insulation Supports. It specifies radial lengths for 70 centimeters (6 inches from the center stud) and 2 meters (19 1/4 inches), noting the use of wire nuts for safety. The resource outlines the construction of a mast from 1/2" ID PVC conduit, connected with 3/8"-24 connecting nuts and bolts, mirroring the Buddipole's modular design. It describes the integration of a mobile dual-band antenna with a 3/8"-24 mounting stud and the custom coax setup with BNC and **PL-259** connectors. Field testing with an FT-817ND and a separate dual-band SWR meter confirmed good SWR on both 2 meters and the 440-450 MHz section of 70 centimeters, with positive reception reports during Field Day activities. Further, the article describes the creation of a custom carrying solution, including a 22-inch tripod bag and a fabric roll-up, to emulate the portability of the original Buddipole system.

A Short Guide to Harmonic Filters for QRP Transmitter Output. - George Dobbs G3RJV

This group is for users of the APRS-IS server software, javAPRSSrvr. Membership is by invitation only.

DK8KW Longwave Information

Pictures of a homemade monoband linear amplifier for 160m band powered by 3 x QB5/1750

Tables comparing attenuation of common coax cables on amateur radio bands

National communications Family Radio Service frequencies divided in 14 channels

Amplifiers, filters, attenuators, mixers, PLL, switches and frequency dividers, signal generators, power detectors, transimpedance amplifiers, variable gain amplifiers and more

Dealer of electronic test equipment dealers since 1977 equipment manufactured by Tektronix, Hewlett Packard, General Radio, Dranetz, Bird, Fluke, ENI, ESI, Wavetek, Narda, Keithley, Weinschel, Microlab/FXR, Systron Donner, Kepco, Lambda

Australian manufacturer of HF Communications Antenna Systems for Military, Comercial, Mining & Amateur Radio

Simply work as many countries and CQ Zones as you can in each calendar year, regardless of the band or mode

Some techniques on homebrewing yagi antennas by VK5AJL

The Langley Amateur Radio Club has been in existence since 1988 and received it's charter in 1989. It has a membership of approximately 20 active amateurs.

Shareware Windows logging program for the 10-10 QSO party

FCC_Call is a program that allows you to create a database from the FCC license records and to look-up the FCC records by call, name or city. It requires TRX-Manager or VB5 runtime installed.

Ham radio or amateur radio has fascinated generations. This Web site reveals the secrets behind its enduring popularity and usefulness.

Constructing a digital interface for the Elecraft K2 transceiver, this resource details the "Fat Wire" design by WG4S. It demonstrates how to integrate a sound card for digital modes, outlining specific connections to the K2's microphone jack and internal audio path. The author shares practical insights from his build, including the use of _RG-62_ coax for its flexible braid and the strategic placement of components like the 2.2K resistor and _2N2222_ transistor. The guide provides a breakdown of the interface's internal wiring, specifying connections for AF In (pin 1), AF Out (pin 5), PTT (pin 2), and Ground (pin 7) on the K2's microphone connector. It also covers the external connections to a laptop's headphone and line-in jacks, along with a DB-9 connector for PTT control via _DTR_ or RTS lines. The author notes that his laptop's headphone output level was sufficient for the K2, negating the need for an attenuator. Reflecting on the design, the author, Dan WG4S, acknowledges a later suggestion to house the components directly within the DB-9 shell for a more compact build. This iterative feedback highlights the ongoing evolution of DIY ham radio projects and the community's collaborative spirit in refining designs.

A summary or tutorial about the basics of the spectrum analyzer, what it is and what it is used for.

SPX Communication Technologies, operating under the TCI International brand, presents a range of radio frequency (RF) solutions primarily for government, defense, and commercial sectors. The offerings include advanced systems for spectrum monitoring, communications intelligence (COMINT), and high-frequency (HF) and medium-frequency (MF) broadcasting and communication antenna systems. Specific product lines encompass _Blackbird_ COMINT systems, _Scout_ spectrum monitoring receivers, and various antenna arrays designed for robust performance in challenging RF environments. The resource details the capabilities of these systems, such as wideband signal detection, direction finding (DF), and signal analysis, crucial for intelligence gathering and regulatory compliance. It also highlights the engineering behind their antenna designs, which are optimized for specific frequency ranges and operational requirements, including high-power broadcast applications and secure military communications. The information presented emphasizes the integration of hardware and software for comprehensive RF situational awareness. The company's focus on empowering partners to "Command the Spectrum" underscores its commitment to delivering critical tools for signal interception, analysis, and management across diverse operational landscapes.

The Vacuum Tube FAQ by Henry Pasternack

Pictures, design plan and description of a 5 element yagi antenna for the 4 meters band by 9A7PJT

A Progressve Communications Receiver by W7ZOI and K5IRK. First published in the November 1981 QST

How to setup a proper antenna feed line with a particular attention to RFI by K0GKJ

QSL printing service operated by OK1FXX in Czech republic

European version of the ICOM IC-7610 leaflet in A4 Format PDF File

Serving Lapeer County & Surrounding Communities in Michigan

This page provides a list of scanner frequencies for hams in the UK. It offers a comprehensive guide for ham radio operators looking to find and tune into various frequencies for communication. The page is useful for hams who want to explore different channels and connect with fellow operators in the UK. Whether you are a beginner or an experienced ham radio enthusiast, this resource can help you discover new frequencies and expand your communication network.

Review site of the Icom IC-706 MkIIG by KV5R

Electronics for Emergency Services Since 1974

TwoWayBattery.com is your source for high quality two way radio replacement batteries, chargers, eliminators and accessories. Batteries for major brands Alinco Icom Kenwood Motorola Uniden Yaesu Standard and more

The resurrection of a R-4C by W7VO

Encouragement for Little Pistols, article originally written for and published in SKIP the monthly newsletter of the Fresno Amateur Radio Club

News, frequency guides and programme information, on shortwave and other international media.

For over 50 years, Communications Specialists Inc. has been a cornerstone in specialized radio frequency solutions, initially gaining prominence with their **CTCSS** and **DTMF** tone signaling products widely used in amateur radio repeaters and commercial two-way radio systems. My own experience with their tone boards in various repeater builds confirms their reliability and ease of integration, a testament to their engineering. The company's legacy in tone encoding and decoding is well-established, providing robust solutions for access control and selective calling. Beyond tone signaling, Com-Spec has diversified into niche markets, including wildlife telemetry, pet tracking collars, and specialized tracking systems for model aircraft and rocketry. Their product line features compact transmitters and receivers designed for specific tracking applications, demonstrating a commitment to precision and durability in challenging environments. While some legacy products are no longer available, Com-Spec continues to innovate, as evidenced by the new R-30M receiver, which ships within five days. This focus on specialized RF applications, from tracking Alzheimer's patients to law enforcement, highlights their unique position in the radio communications industry.

High speed telegraphy without key clicks by SM5BSZ

Mobile RFI, often manifesting as persistent noise in the receiver even with the antenna disconnected, frequently originates from the vehicle's power supply system. This guide details systematic troubleshooting steps, beginning with isolating the radio from the car's 12-volt supply to confirm the power system as the noise source. It emphasizes the critical importance of drawing power directly from the battery using **heavy gauge wire**, bypassing the fuse block to leverage the battery's natural capacitance for RFI suppression and ensuring a solid RF ground. Proper routing of power lines through the firewall is also covered, advocating for dedicated grommeted holes to prevent inductive coupling from other wiring harnesses. The article stresses the necessity of fusing both positive and negative leads from the battery, a crucial safety measure to prevent damage to the rig and mitigate high-current risks should the battery's engine block ground become compromised during service. Addressing **alternator whine**, a common high-pitched noise that varies with engine speed, the resource suggests checking battery connections and the alternator-to-battery harness for looseness or corrosion. It also mentions the utility of adding an external RF noise suppression capacitor in parallel with the alternator's internal capacitor for enhanced filtering, and the effectiveness of commercially available in-line power supply filters.