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The intent of this article is to help the semi-non-technical person understand what is inside the Drake TR-7(A) Transceiver, how it works, and discusses simple adjustment and modifications the end-user can perform

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

The Vacuum Tube FAQ by Henry Pasternack

The purpose of this book is to provide a common source for WIRES-X, gather information from manuals, experiences from the Amateur Radio Community, and the best practices from both the Amateur Radio Community and the Bakken Amateur Radio Society. To provide a platform for learning, experimentation, and advancement of Amateur Radio skills and art. A platform of Discovery and to have FUN. To encourage networking, sharing, and exchange of interesting technical information of WIRES X, where people are encouraged to help each other out.

Technical specifications and details of the Yaesu FL-2100B HF Power Amplifier

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

The resurrection of a R-4C by W7VO

This article shows how to power an amateur radio station from solar power using four kits that have been designed to work together in a modular way, each kit provides a unique function.

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.

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.

The SDRanywhere application is an Android app that allows remote operation of an RFSPACE SDR-IQ, NetSDR, SDR-IP or Cloud-IQ radio from anywhere in the world. The demodulated audio and waterfall information is compressed and sent to the client application using a low bandwidth internet connection.

My place in cyberspace for thinking out loud about the Three Rivers Area Montioring Association and its Sunday evening Pittsburgh Area Scanner Net as well as ham radio and the Linux operating system

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

Quilon Amateur Radio League Kollam Kerala INDIA

An interesting presetnation full of usefull tricks to correctly design and build 23 cm Yagi using simple tools. The basic design of the antenna presented in this document is taken from the original DL6WU Yagi Design published in 1982

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.

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.

Balloon Experiments with Amateur Radio

Tables comparing attenuation of common coax cables on amateur radio bands

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

Plastic tubing and custom plastic tubing from a manufacturer that specializes in the custom manufacturing of close tolerance plastic tubing products.

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

A homemade 23 cm transverter project with several building steps and pictures

Test equipment, counters and meters

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.

80 watt multi-mode amplifier using one of the newer S-AV36 Toshiba modules. Less than 50 milliwatts will drive it to full output in any mode.

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

Information on ham radio or amateur radio (radio amatur)

A sound file collection of QRP contacts by AE5X

Using absurdly low-speed CW for "communications"

High speed telegraphy without key clicks by SM5BSZ

Raytown Amateur Radio Club - Kansas City/Rsytown, Missouri

A kit Digital VFO with pre-soldered surface mount parts and burned-in firmware, a scratch build with Arduino Nano, C code with modifications, and a Silicon Labs si5351 PLL clock generator on a breakout board.

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.

While intended mainly for antenna loading coils, this article also applies to other resonant systems, such as amplifier tank circuits.

Battery-powered monitor designed to provide an audible indication of keying for those whose rigs lack a CW sidetone

A web site for those interested in ham radio Software Defined Radio (SDR). SDR Zone provide forums, reviews and user blogs relating to any type of SDR

STC, AWA, Valve Radio, Airzone, Kriesler, Mullard, Western Electric, dating Australian radios

These are QRP rated 3 Pole Butterworth filters based on a design by K4VX, feature simplicity, almost no insertion loss, and reasonable rejection on the other ham bands.

Heavy duty digital multimeters

Electronics for Emergency Services Since 1974

The Ham Cram method is designed to prepare you for the FCC tests in the shortest time possible giving you the highest level of confidence. It's totally free.

Build you own RF probe, measure the level of RF voltage present at a particular point.

100-watt UHF repeater (444.500+ PL100) and a 6-meter repeater (53.68- PL114.8) are owned and maintained by South County ARES to support emergency communications for Belmont, East Palo Alto, Foster City, Menlo Park/Atherton, Redwood City, San Carlos, San Mateo, and Woodside/Portola Valley. The organization emphasizes training, including weekly nets and practice sessions, to improve message passing accuracy and brevity, crucial skills for **emergency communication**. Resources like the San Mateo County Sheriff's Office Ham Radio Frequency Plan Recommendation and **Chirp-compatible CSV files** for Baofeng radios are provided. Participation in community events is encouraged to build skills and connections among members. The group operates without collecting dues, relying on donations and member contributions of time and expertise. Training pages are available for new hams and those seeking license upgrades, along with a "Tips for New Hams" section. The site also features a monthly calendar of events, including board meetings, general meetings, and hospital nets, alongside a newsletter, the "South County Communicator," and various operational documents like the Net Control Manual and SCARES Handbook.

A Collection of EME Reflector Antennas and YAGI Arrays.

IK6CAC windows shareware program to manage the USA County Award

Electronic components distributor