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If your local repeater has got you singing the PL tone blues, then read on. For less than $10, an inexpensive PL tone generator can be constructed that will bring new life into that old non-PL rig.

Design for a very low cost 6-digit frequency counter module using of the shelf components

A restored version of the original CQ DX Zones of the world

A compact Quad Antenna for the HF Bands by GM0ONX

Recordings of shortwave numbers stations

CB and ham radio dealer in spain

This is the report of a MFJ-259B analysis of two 100 ohm / 5 watts resistors in parallel partially in italian

Map of ITU and IARU Zones at hamatlas.eu

The Truth about the G5RV Antenna, how to optimize the design to be more efficient on all bands

An inexpensive condenser microphone with excellent performance can be easily constructed with easily available parts.

The Nato and Western Union Phonetic Alphabets useful for spelling words and names over the phone.

CTCSS Decoder and Encoder, DTMF Decoder projects

The TS850s connector pinouts for Mic,acc2, acc1 and remote connector

IK1PML Tipolitografia Bevione QSL Printer in Italy

A mobile vertical antenna for 40 meters band by W4NFR

HF Weather Fax lets you receive marine weather radiofascimile transmissions on your iPad, iPhone and iPod Touch. Just connect it to a shortwave radio tune in a weather fax frequency, and watch the images come in.

A discone antenna plan and pictures with renderings designe mainly for RTLSDR usage

Official, and updated CQ Magazine Countries and Zone List available in various formats, text, word and excel formats.

International Components Corporation has an extensive range of electronic components consisting of audible signal devices, speakers, microphones, capacitors, electron tubes, connectors, and accessories designed in recognition of the diversity of applications and special characteristics encountered by designers in today's complex world.

ON6MU 4 A power supply using a BDX33

This online guide details the microphone pinout for the Kenwood TR-7950 transceiver, specifically addressing the wiring configuration for a dynamic mobile microphone with a **500 Ohm** impedance. It provides a pin-by-pin breakdown for the 6-pin microphone connector, identifying the function of each active pin. The resource specifies that Pin #1 is for the microphone audio (white wire), Pin #2 controls the _PTT_ (black wire), Pin #3 activates the memory down function (blue wire), and Pin #4 controls the memory up function (red wire). Pin #6 is designated as the ground connection, while Pin #5 remains unused in this configuration. The document focuses on the physical wiring necessary to restore microphone functionality to the Kenwood TR-7950, a transceiver capable of **45 watts** output on the _2m band_. It directly addresses the technical challenge of re-establishing correct electrical connections after microphone wires have been disconnected from the connector. The information facilitates proper microphone operation for simplex QSOs and other voice communications. DXZone Focus: Online Guide | Microphone Pinout | Kenwood TR-7950 | PTT Wiring

Homebrewing a mic boom headset for the Yaesu FT 897 and 857 transceivers

Shure incorporated, microphones and audio electronics

Standard time zone map of the world in a jpeg file

An home made Butternut HF9V clone antenna by OH2GVB

Key your transmitter from the tone output of a Morse Code generator program

Operating on the amateur radio bands, DXers rely on timely information to chase rare contacts. This resource offers a specialized web interface for accessing DX cluster data, specifically designed for mobile phone displays. It presents real-time **DX spots** in a compact, easy-to-read format, stripping away extraneous elements often found on traditional cluster interfaces. The core functionality focuses on delivering essential spotting information—callsign, frequency, mode, and comments—without requiring complex navigation or excessive data loading, which is crucial for mobile data usage. The utility of this mobile-first design becomes apparent when operating portable or away from a shack. Unlike full-featured _telnet clusters_ or web-based aggregators, DXLite prioritizes quick access and readability on small screens. The interface displays a continuous stream of spots, allowing operators to rapidly identify potential DX opportunities across various bands. Its minimalist approach ensures fast loading times and efficient data consumption, making it a practical tool for on-the-go DXing and contesting.

2 Meter Indoor Slim Jim Antennas for Cyclone Season and Other Uses by VK4MDX

The basics of what is a discone antenna for wide band or bandwidth omnidirectional applications.

Cushcraft X7 20-15-10 Meter 7 element beam Assembly & Installation

The widest range of stocked components for the electronics, electrical and mechanical engineer.

Generates Morse tones using the Soundcard. A neat tool for sending out short sequences of Morse tones.

Amateur radio cartoons by Woody Epp W7EPP

Makers of universal digital rotor controllers including wireless controllers

Microphone wiring for Yaesu FT-757 GX II

This was the blogger home page of the Resonant Frequency podcast. Follow the link to get to new web site.

Demonstrates the construction and implementation of a **two-element phased vertical array** for 40 meters, utilizing _Christman phasing_ techniques. The author, W4NFR, details the process from building individual 1/4-wave aluminum verticals to integrating them into a phased system. The resource covers antenna spacing of 32 feet, elevated radial design, and the critical steps for tuning each vertical to achieve a 1.1:1 SWR before combining them. It also provides insights into calculating precise coax lengths for feedlines and the phasing delay line, emphasizing the use of an MFJ-269 Antenna Analyzer for verification. The finished system exhibits good front-to-back nulls, with an overall SWR ranging from 1.6:1 to 2.2:1, which is managed by an antenna tuner. The project includes detailed photos of the relay box, showing 12 VDC relays capable of handling 5KV, and the control box in the shack for switching between three different antenna pattern configurations. Static bleed-off chokes are incorporated for protection, and the construction emphasizes robust weatherproofing for outdoor elements.

Electronic surplus dealer

A large printable PDF file representing the world time zones. This map gives an overview of current local times around the world. If you ever asked yourself what time zone am i in, find your answer here.

A site dedicated for the AM Radio Amateur and vintage radio. Home of the AM Press/Exchange, The AM Forum (the largest BBS of it's kind),and The AM Classifieds, Photos, Audio, and technical information. Audio and Video chat rooms.

Antartica 2006

The Elecraft K2 transceiver requires specific modifications for optimal soundcard digital mode operation, particularly for PSK31. The original article, circa 2001, details initial challenges with manual PTT and speech compression settings. A key modification involves adding headphone audio and a compression disable signal to the K2's microphone jack, utilizing pins 4 and 5. The **COMP0** signal, active low, is shorted to ground via a non-inverting open collector switch circuit, comprising two resistors and two transistors, mounted on the SSB board near U3. This circuit provides effective control of an analog signal line with good noise immunity. The switchbox itself repurposes a computer COM port switch, using only two of its original connectors and four of the nine poles. It integrates a microphone preamplifier, a PTT circuit built with 'flying leads' construction, and RCA jacks for soundcard connections. A trimpot adjusts the audio drive to the K2. The central DB9 connector links to the K2's mic connector via a shielded RS232 serial cable, ensuring proper grounding and signal routing. An external footswitch PTT jack is also included. Further enhancements include a **noise-canceling microphone** preamp based on a QST December 2000 article, adapted for Heil mic elements. This preamp, built with pseudo-Manhattan style construction, provides a gain of approximately 2 by changing emitter resistors (R9 and R16) from 680 ohms to 330 ohms. A 10-ohm series resistor and 47 µF capacitor on the +5V supply mitigate noise spikes.

This article loaded with nice pictures and schematics, describes a 160-10 meter linear amplifier that uses a pair of 3-500Z triode power tubes. It was designed and constructed by William Moneysmith, W4NFR. The amplifier features fast warm up and 1500-Watt RF output with 100-Watts of drive.

This circuit stores a single morse code message as bits in an EPROM chip, the message is sent to a relay which can key a CW transmitter.

KARSFEST, held at the Will County Fairgrounds. Sponsored by the Kankakee Area Radio Society. Large and well attended hamfest and computer show!

Explore this high-resolution ITU Zones Map, a critical reference resource for amateur radio operators, international broadcasters, and telecommunications engineers. Originally established by the International Telecommunication Union – Radiocommunication Sector (ITU-R) Broadcasting Services Division (1999), this chart accurately divides the globe into 90 specific CIRAF zones. This authoritative visual guide is indispensable for planning High Frequency (HF) radio propagation, scheduling international broadcasts, and verifying locations for radio contests and awards. Distinct from the 40 CQ Zones, the ITU zoning system provides the official administrative framework used for global frequency management. This digitally enhanced version ensures maximum clarity of zone boundaries and numbering (e.g., Zone 28 for Central Europe), making it an essential tool for technical accuracy in logbooks and station management. It serves as a trustworthy standard for educators, hobbyists, and industry professionals alike.

A selection of alphabets used, particularly by ham radio operators, to spell out words

If you need a cheap and easy to construct Subtone Generator for EU-model VHF-UHF rig, here is a solution that works very well.

Telephone EMI, questions and answers on how to solve interference problems to phone lines

Low signal, noise-high AC gain preamplifier