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Test equipment, counters and meters

A sound file collection of QRP contacts by AE5X

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.

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.

A 500 kHz to 5.5GHz 2-port vector network analyzer designed for use with any Linux, Windows or MacOS computer. High performance: up to 80 dB dynamic range in the MHz range; up to 40 dB in the GHz range

Using absurdly low-speed CW for "communications"

Raytown Amateur Radio Club - Kansas City/Rsytown, Missouri

We stock a range of two way PMR446 radios. PMR 446 is a license free frequency, which means that you can communicate for up to 3km (terrain allowing) without any call charges or license requirements. They can be used in most European countries and are ideal for holiday trips.

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

A Collection of EME Reflector Antennas and YAGI Arrays.

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

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

High speed telegraphy without key clicks by SM5BSZ

Heavy duty digital multimeters

The Broadcast Employees Amateur Radio Society, Inc. (BEARS) operates an extensive network of **VHF and UHF repeaters** across New York, the Hudson Valley, Long Island, and New Jersey, accessible to all licensed amateur radio operators. This resource details the club's structure as a 501c3 tax-exempt non-profit, emphasizing its role in providing ham radio training, testing, and critical communications support to various public and private emergency response agencies. Key repeaters include W2ABC/RPT on 147.27 MHz with a 141.3 PL tone, serving as a central point for club activities and broader network access. BEARS is also a founding member of the **Disney Amateur Radio Interconnect (DARI)**, a consortium of open, linked VHF and UHF repeaters spanning major metropolitan areas such as Philadelphia, Baltimore/Washington DC, Orlando, Bristol, Los Angeles, and Boston. This interconnected system facilitates wide-area communication for members and supports emergency preparedness efforts across multiple regions. The club's focus extends beyond Disney employees, welcoming aspiring and current hams from outside the company to participate in its activities and utilize its robust repeater infrastructure.

Gage applied technologies designs and manufactures high-speed data acquisition systems, high-speed digitizers in pci / cpci / pxi or pc oscilloscopes, providing utmost measurement fidelity for high frequency signals.

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

LPI personnel have combined experience over many years in servicing customers throughout the world. Our experience covers projects in some of the most lightning prone areas.

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.

Kingston, Ontario, Canada A RAC Affiliated Club

Electronic components distributor

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

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

A keyed piezo beeper, connected to the microphone jack of a HT, appeared feasible as a ready-made MCW generator.

Basic information in spanish hon how to become ham radio operators, or radioaficionados

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.

Electronics for Emergency Services Since 1974

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.

K8CU technical topics article about high voltage breakdown tester necessary for testing of any high voltage components like vacuum tubes, high voltage capacitors, vacuum relay

Maxdao: offer you 7/16, N coaxial connectors, jumper cables, feeder clamps and grouding kits, surge arresters & brackets, wall entries and microwave components used in base tower, power dividers, couplers

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

The workaday world of antenna & tower projects. Posted by K4ZA, Tower Works, Charlotte NC.

IK6CAC windows shareware program to manage the USA County Award

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

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

We encourage ham radio operators to try something new with the hobby.

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.

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

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.

This low pass filter terminates all harmonics from the 2nd to above the 10th harmonic in a better than 15 db return loss load

The Hermes-Lite is a low-cost direct down/up conversion software defined amateur radio HF transceiver based on a broadband modem chip and the Hermes SDR project. It is entirely open source and open hardware, including the tools used for design and fabrication files. Over 300 Hermes-Lite 2.0 units have been successfully built.

SSTV & ATV "only" Webring. Many members world wide.

Tti is thurlby thandar instruments who manufactures advanced electronic test equipment for sale in the uk and throughout the world.

This site was established to encourage hams, especially the newcomer, to share the enjoyment that comes from owning and operating Collins

QSL printing service operated by OK1FXX in Czech republic

A collection of modifications for the Icom IC706 transceiver

Manufacturer of Repeater Controllers, Repeater Tone Panels and Telephone Interconnect.

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 project for a vertical antenna for 60 to 20 meters by KV5R