Search results

BaseStation is a Windows application written originally for the SBS-1 family of Virtual Radar Receivers.

Scans of original G2DAF articles on his HF linear amplifier using QY3-125 tube

Moon tracking for Mac Windows and Linux for EME by GM4JJJ

Official homepage of the Ukrainian radio amateur UR-QRP Club

The 11-meter band, often associated with Citizens Band (CB) radio, presents unique challenges and opportunities for long-distance communication, particularly for operators interested in DXing. This group facilitates discussions and information exchange among enthusiasts who operate on this frequency, often utilizing single-sideband (SSB) modulation for improved range and signal clarity compared to traditional AM CB operations. The community provides a platform for members to share experiences, technical insights, and propagation reports relevant to 27 MHz operations. Members engage in discussions covering various aspects of 11-meter DX, including antenna configurations, transceiver modifications, and operating techniques to maximize signal propagation across continents. The forum serves as a central hub for coordinating contacts, sharing QSL information, and celebrating successful long-haul QSOs. Specific topics often include optimizing power output, reducing noise, and understanding solar cycle effects on 27 MHz. The group's activities extend to organizing virtual gatherings and promoting ethical operating practices within the 11-meter DX community. It supports both seasoned operators and those new to the band, fostering a collaborative environment for exploring the capabilities of CB radio beyond local communications.

Two modes of propagation at 50MHz E-layer & Sporadic-E by Ken G4IGO

Demonstrates the design and construction of a compact, portable multi-band mini-delta loop antenna, specifically optimized for /P (portable) operations from remote locations like Scottish islands. The resource covers the theoretical underpinnings of half-wave loops, contrasting closed and open configurations, and then details the application of a folded dipole principle to achieve a 50-ohm match for direct coax feed. It presents empirical formulas for calculating element lengths, considering the velocity factor of common wire types, and provides a detailed example for a 20m (14.175 MHz) version. The article includes a comprehensive table of dimensions and allowances for a five-band (20m, 17m, 15m, 12m, 10m) mini-delta beam, along with construction hints for the central support and balun. It specifies a 1:1 trifilar balun wound on a ferrite rod and describes the antenna adjustment process using an _MFJ-259B Antenna Analyser_. Initial test results indicate an SWR of 1:1 at resonance and a bandwidth of approximately 240 kHz on 20m, even at a low height of five feet above ground. The distinctive utility lies in its focus on a practical, easily deployable beam antenna for portable DXing, offering a viable alternative to more complex or larger arrays.

Website dedicated to Coastal Radio Stations, includes frequency lists for memdium frequencies maritime stations

A simple accurate power splitter for the 70cm uplink to Oscar 13

FREE bring & buy website for UK radio amateurs

Chip64 mp3 file

This article presents a technical investigation into spurious emissions from the Yaesu FT-847 transceiver when operating on the 70MHz (4-meter) band. The author discovered significant problems with both factory "UK spec" and modified units. Spectrum analysis revealed that when transmitting at 70.2MHz, the radio produces numerous spurious signals, with the most prominent emission at 45.6MHz measuring only 3dB below the fundamental frequency. The study also documents poor power efficiency on 4m (10.3% at 30W output) compared to 6m operation (23.5% at 30W). Tests verified that jumper configurations had no effect on filter selection. The author warns that using these radios on 4m may violate license conditions due to excessive spurious emissions.

Circuit diagrams drake tr7, Schaltbilder Drake Tr7, antenna tuners, baluns, and home brew power supplies, dual tone ssb test generator, zweiton ssb test generator, zweiton testgenerator, dual tone test generator by DK4DDS

news and views from the UK about the course of CB in the U.K. and Europe.

Excellent slides explaining radio and radiowaves generation basics

Presents a dynamic, searchable database of shortwave broadcast schedules from around the world, enabling users to locate active stations or plan listening sessions based on scheduled transmission periods and frequencies. The resource details specific station names, such as _Radio Habana Cuba_, _Deutsche Welle_, and _All India Radio_, alongside their operational times and assigned kilohertz frequencies. It also incorporates a distance calculator, which leverages geographical coordinates to estimate propagation paths, though it notes occasional data inaccuracies leading to transmitters appearing in oceanic locations. The platform's development log highlights continuous updates, including the integration of new seasonal schedules like "A24 frequencies" and "B23 schedule," reflecting the fluid nature of shortwave broadcasting. It documents challenges with geolocation services, particularly concerning Google API changes that impacted distance calculations and required user-side browser configuration adjustments for optimal functionality. The site owner, VAXXi, frequently communicates these technical adjustments and database updates, often acknowledging user contributions and donations. Distinctively, the resource provides a historical perspective through its update archives, illustrating the evolution of shortwave listening over more than a decade since its inception in 2011. It also mentions specific events, such as the BBC adding shortwave broadcasts for Ukraine on 5875 kHz and 15735 kHz, demonstrating its responsiveness to global events impacting broadcast schedules. The site's commitment to user feedback is evident in its bug reporting and feature request mechanisms, contributing to its ongoing refinement.

An unused 5v supply connection allows an electret condenser microphone element to be used in place of the standard dynamic element. Modification by M0UKD

Working DX on a Dead 50MHz Band using Meteor Scatter, by Palle Preben-Hansen, OZ1RH

Calculate online, ERP in dB and dBi given PWR Frequency Coax lenght and type and antenna type

By Ken Willis, G8VR

This simple modification is applicable to pretty much any 12 volt operated, positive earth equipment. by Chris Cox, N0UK, G4JEC

FM dx logs, MW carrier offset monitoring, lists of RDS codes in use in the UK, London pirate bandscan and much more from a London QTH.

The UK amateur radio licensing scheme features three distinct tiers: Foundation, Intermediate, and Full, each granting specific operating privileges. For instance, the **Foundation Licence** permits a maximum of 10 watts output power on most allocated bands, with restricted band access. The Intermediate Licence allows up to 50 watts, while the **Full Licence** grants access to the maximum UK legal power limits and all available amateur radio band allocations. UK call sign prefixes and formats provide insights into the licensee's class and the approximate issuance date. For example, M3, M6, and M7 prefixes with three letters denote Foundation Licences issued from 2002, 2008, and 2018 respectively. Intermediate Licences, often starting with "2E0" or "2E1" followed by three letters, were issued from 1991 onwards. Full Licences encompass a broader range of prefixes like G2, G3, G4, G0, and M0, with varying letter counts indicating different historical license classes and issuance periods, such as G3 plus three letters issued between 1946 and 1971. Special prefixes like GB are reserved for repeaters, beacons, data mailboxes, and special event stations, with specific numerical sequences (e.g., GB3 for repeaters, GB7 for data repeaters/mailboxes) indicating their function. Optional prefixes such as GC, GD, GI, GM, and GW denote specific UK countries (e.g., Wales, Isle of Man, Northern Ireland, Scotland, England) and can also signify club stations.

AR-82000 software

A simple and inexpensive way to connect an AR8000 to a portable computer

An inverted Vee antenna calculator that consider also minimun vertical height and horizontal spread by M0UKD

On-Line CB Radio and truck accessory shop based in UK

CB Radio and 10 meter Radio reviews & mods blog. Most articles are in Japanese

This document details the design and construction of a Vinecom 6N4 dual-band Yagi antenna for the 50MHz (6-meter) and 70MHz (4-meter) amateur radio bands. The antenna features 9 total elements (4 elements for 50MHz, 5 elements for 70MHz) on a 4.236-meter aluminum boom. Computer simulations using MMANA software predict 7.21 dBd gain on both bands with front-to-back ratios of 16.01dB (6m) and 15.37dB (4m). The design uses 12.7mm diameter elements mounted on a 32mm square boom, weighing 5.7kg total. Practical measurements with an MFJ-269 analyzer confirmed good SWR performance across both bands after element length adjustments.

This is an interactive design package for designing analogue (i.e. hardware) filters made of inductors and capacitors (Ls and Cs).

In the long history of beam aerials there has persistently existed the claim that certain types of aerials perform better than yagis.

Review by Peter Bacon, G3ZSS

A PDF presentation of a home made moxon antenna for 50 MHz 70 MHz and 144 Mhz. The project is mainly out of surplus plastic Plumbing pipes and clips etc, and also details of how the dimensions were calculated.

Small and inexpensive homebrew HF radio 5W Output, CW SSB AM FM, DSP, Speech Processor, Sprectrum Scope, Watefall Display. mcHF is a small, home-brewed amateur radio project. Firmware is released as open source.

AM-6154 222MHz grid Conversion Information by N0UK

The Amateur Radio Society of ROYAL SIGNALS (British Army), 1550 Members. MERCURY Journal issued three times a year (Editor G3NVK) Regular (daily) Nets. Awards and Contests. Own QSL Bureau. E-mail List Server open to all. Regularly updated Web Site (Web Master G3NVK) includes EASYMAIL facility, Guest Book, Photo Gallery, Society Rules, Military Museums.

Homebrew a compact yagi antenna for 14 Mhz suitable for those with small plots based on a design by AB4GX

Are you suffering from TVI? Then why not try this filter for size. It is a three-stage high-pass filter that blocks low-frequency 50MHz signals while letting through UHF TV.

A javascript online calculator of bearing and distances by G4VWL

Luksa industries design and manufacture mechanically operated aluminum telescoping masts and telescoping tripods to support communications and military antennas

Remote control L match Aerial Tuning Unit

Buy old manuals, military radios, kits, receivers online shop

20 Watt Power Amp for Softrock or for QRP transceivers by M0RZF

Building a 2 metre 144MHz VHF Yagi beam antenna, designed for portable use.

A DIY project of a WiFi 10 elements Yagi antenna

Dedicated to State-of-the-Art lightweight portable radio. Sotabeams produces and sells amateur radio products dedicated to ham radio portable operations. Antennas, supports and masts, filters, wires and more accessories for amateur radio.

Personal Web Site of UX7CQ. Information about Ukraine. Old military radios collection. CW Straight Keys.

An excellent introduction to ham radio bands, which bands to use and when.

How to make a half l or quarter l coax cable for a specific frequency

A magnetic longwire unun with a T130-2 Iron Powder core by M0UKD