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History of codes of the world, russian codes, visual codes, and al long collection of telegraph codes as used worlwide including the international morse code and the relative variations

Electro-Voice Model 664 (EV 664) cardioid microphone, wiring diagram, pictures and data sheet

Learn how to start using ham radio satellites for your DX contacts, PDF presentation by Dave Long

In this PDF article Zack Lau describe how to homebrew a four element yagi beam antenna for 50 MHz band, including how to build mounting blocks and tubing clamps to hold elements.

The Packet Radio beginners guide to packet radio operating by Buck Rogers K4ABT

A trap on the coaxial cable, also known as choke, helps to eliminate the sneaking of the reflected RF- energy to the shack. The trap can be made from the coaxial cable that feeds the antenna

Technical supplement with schematics of the Yaesu FT-2800M Yaesu Transceiver

Schematic diagram of the VLA 200 power amplifier by RM Italy

VHF Power amplifier VLA 200 english manual

These photos illustrate the basic steps in making a perfect solder joint on a p.c.b

Over 100 amateur radio beacon audio files are presented, offering a direct auditory experience of propagation conditions across a wide spectrum of frequencies, from 1.8 MHz to 47 GHz. These recordings, primarily captured by IW3FZQ and IK3NWX, document signals from beacons such as DK0WCY, IY4M, GB3RAL, and S55ZRS, providing a valuable resource for **propagation study** and **beacon monitoring**. Each entry in the list specifies the beacon's callsign, its operating frequency in kHz, and the recording operator. This compilation includes signals from beacons located in various grid squares like JN55VF, JO44VQ, and IO91IN, illustrating diverse geographical origins. The frequencies covered span the 160m, 80m, 40m, 30m, 20m, 17m, 15m, 12m, 10m, 6m, 4m, 2m, 70cm, 23cm, 6cm, 3cm, 1.2cm, and 6mm amateur bands. Users can listen to these recordings to identify characteristic beacon tones and observe signal strength variations. The resource also invites other radio amateurs to contribute their own beacon audio files, fostering a collaborative archive of propagation data. The last update to this collection was on March 24, 2009, indicating a historical snapshot of beacon activity. Accessing the files requires the Real Player software.

International crystal manufacturing provides quartz crystals, oscillators, precision crystals, filters, tcxos / vctcxos, qcm crystals, and other frequency control products. read details about our crystals and frequency control products and services.

Shortwave listeners and amateur radio operators interested in _numbers stations_ can engage with this mailing list, which serves as a platform for discussing the enigmatic transmissions. The resource facilitates the exchange of information regarding these unusual broadcasts, often associated with intelligence agencies, by allowing members to share observations, decode attempts, and theories. It provides a community space for those who monitor the HF spectrum for these unique, often automated, voice or digital signals. Participation on the list enables members to contribute to a collective understanding of numbers station activity, including changes in frequencies, broadcast schedules, and message formats. While specific technical analysis or signal processing techniques are discussed by members, the primary function is information sharing. The list is administered by csmolinski at blackcatsystems.com, and prior postings are archived for reference, allowing new members to review historical discussions and data.

CAT5 T-568B Colour Code for RJ-45 Plug

Improving measurement accuracy when low-power analyzers are used.

A parabolic dish ring feed optimum resonance frequency of 1325MHz

Find out how much to adjust the length of a quarter wave whip or a half wave dipole rather than the outright cut-and-try method.

A home made 4:1 Ferrite QRO Bal-un with a FB 241-61 Type K

The resource details the construction of a multiband trap-style Inverted-V antenna designed for operation on 3.5 MHz, 7 MHz, 14 MHz, 21 MHz, and 28 MHz. It presents specific winding data for the traps, including the number of turns, wire gauge, and coil former dimensions, crucial for achieving resonance on the target bands. The document provides a parts list and a diagram illustrating the antenna's physical layout and trap placement. It outlines the process for building the traps using PVC pipe formers and specifies the required capacitor values for each trap. The design emphasizes a practical approach to achieving multiband operation with a single feedline, a common goal for HF operators with limited space. The document includes a table with antenna segment lengths for each band, allowing for precise replication of the design. It also offers insights into tuning and adjustment, ensuring the antenna performs optimally across the designated amateur radio bands.

Guide to soldering an desoldering

Over 45 years of dedicated work by Robert Sherwood, NC0B, culminated in a wealth of technical insights, particularly concerning **receiver performance** and the intricacies of transceiver design. The site provides access to numerous presentations from events like Dayton Contest University and W4DXCC, covering topics such as optimizing rig performance, the evolution of lab testing, and the impact of roofing filters on transmitted IMD and receiver characteristics. These resources offer detailed analyses and practical advice for serious operators and contesters. While product manufacturing, including the SE-3 MK IV synchronous detector and various Drake R-4C accessories like roofing filters and cooling kits, has ceased, the legacy of technical documentation remains. The site details specific products like the Icom IC-781 and R-9000, and offers insights into 455 kHz mechanical and crystal filters, along with DSP protection strategies. Crucially, the site features extensive receiver test data, allowing radio amateurs to compare the performance of various transceivers. This data, often presented in white papers and slide shows, includes detailed measurements and explanations of key performance metrics, serving as a valuable reference for understanding and selecting high-performance HF gear.

An interesting article on guanella baluns that cover several aspects of homebrewing 1:1 and 4:1 current baluns by KN9B

The WaveNode WN-1 is a precision, full-featured Amateur Radio Station Monitoring System which now includes Audio Announcing for RF power, SWR, and DC monitoring using HF and UHF remote sensors.

**LDG Z100** automatic tuner repair focuses on toroid replacement and troubleshooting. The guide provides detailed steps for diagnosing and fixing common issues with the toroid, which is crucial for the tuner's performance. It includes specific instructions on disassembling the unit, identifying faulty components, and sourcing replacements. The document is technical, requiring familiarity with electronic components and soldering techniques. It emphasizes the importance of using the correct toroid specifications to ensure optimal functionality. Successful repair of the **LDG Z100** ATU restores its ability to match a wide range of antennas, enhancing transmission efficiency. The guide compares the performance before and after the repair, highlighting improvements in SWR readings and overall reliability. Practical application of this repair extends the life of the tuner, making it a cost-effective solution for amateur radio operators. The document serves as a reference for similar repairs on other models, providing insights into common issues and solutions. It is a valuable resource for those looking to maintain their equipment without resorting to professional services.

Diamond W8010 Multiband Dipole Modifications

QST Magazine, 1991 July, review of the Kenwood TS-850S 160-10 Meter Transceiver

Ameritron QSK 5 PC mod for AL80B

An ham radio contest log sheet in a PDF US letter printable format, can be used for portable operations, free to print and download.

VK Contest Log (VKCL) is a free contest log software specialising in Australasian contests but also covering some international ones too. Author is SK, you can donwnload the latest version 4.15.

Globe-S for RTL1090 is a light radar viewer for RTL1090. It communciates via a HTTP interface and can be interfaced over long distances.

Six elements yagi antenna for 6 meters band. This antenna design is based on the QuickYagi 4 software by WA7RAI, uses a 6.5 m boom, feature 12.0 dBi gain and 35dB front/back

Study of the Coaxial Dipole: Just how does this thing work.

Used in the Kenwood TM-241, TM-741 2m module by W3KKC

A complete guide to undestand and know how electret condensor microphone elements works by K3DAV

PEP RF output power measurement, and examples RF output power measurements

Basic guide on soldering techniques, tips and tricks

An home made low pass filter for 70 MHz by IK0VAQ

Top quality Microwave Phase Locked oscillators for DB6NT, DEMI and homebrew microwave transverters, and other support products.

Cushcraft A3S performances with the A743 kit to add 30 and 40 meters

Around 200 electronic circuits in pdf format or images, There are also over 1000 links to useful electronics, freeware, open source websites. There are some 100 useful documents, software and pcbs too. Mainly industrial electronics, instrumentation. Covers Various aspects of electronics and basics of circuit design.

Key facts about how to solder, how to solder wire, how to solder pcb's, and including general soldering techniques and the best ways of making good solder joints for electronic circuits and construction. Includes video

Comparing the ICOM IC-7600 and the Yaesu FTDX-3000

There are many designs for building preamps each with their own advantages and disvantages. In this PDF Article author reviews several different types.

How to measure the characteristic impedance of a unknown transmission line using MiniVNA

A video about secret listeners ham radio voluntary interceptors during ww2 an extract from The Secret Wireless War DVD

About the Cushcraft A3S with A743 add-on for 30 an 40 meters

EB5AGV Workbench: Yaesu FL-2100B amplifier restoration

A 160W linear amplifier for 4 meters band based on GI0GDP

This resource, a blog from the Penang Amateur Radio Club (PARC), offers insights into various aspects of amateur radio in Malaysia. One post details monitoring Automatic Terminal Information Service (ATIS) on the 2m band, providing specific frequencies like 122.750 MHz AM for Butterworth and 126.400 MHz AM for Penang, along with sample aviation weather and operational data. Another entry critiques the lengthy and costly process of obtaining an amateur radio license in Malaysia, contrasting it with the more streamlined FCC licensing system in the United States, citing a 1-year wait and RM 414 (USD 125) for 10 years in Malaysia versus 3 weeks and USD 14 for 10 years in the US. The blog also covers internal club matters, such as the 2007 Annual General Meeting (AGM) attendance and council elections, highlighting member dissatisfaction with outdated newsletters and a call for "reformasi." Additionally, it presents local phonetic alphabets in Bahasa Malaysia and Chinese, and discusses monitoring AM broadcast bands for international stations like Voice of America on 1575 kHz and Zhong Yang Ren Min Guang Bo Dian Tai on 1134 kHz, offering alternatives to local 2m repeater chatter. The author, "firstclass," shares personal observations and criticisms regarding the Malaysian ham radio landscape.

Cushcraft XM240 transformation into a Moxon antenna by W6NL