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6m/2m/70cm Yagi Antenna Built from Old TV Antenna This turned out to be a great little antenna. It works the 6 meter, 2 meter and 70 centimeter bands. You can use one common feedpoint or two seperate feedpoints depending on how you would like to connect this antenna to your transceiver.

A collection of drawings of most popular wire antennas for hf ham radio bands

Port of the popular VOACAP program, HF propagation prediction tool. It may be compiled using the GCC GFortran compiler

Domino is the name given by the developers to a family of IFK coded coherent phase single tone MFSK keyed modes, using sequential tone-pairs in two alternate fields arranged as orthogonal but interleaved tone sets.

This circuit will let you look at the signal and frequency output of your transceiver.

Projects you can build, an amplified shaped sine-wave oscillator

With the bluecat interface it is possibile to connect a Yaesu FT 817 857 897 to a computer or a android smartphone without any cable or interface, using a bluetooth wireless connection

1500 watts of RF output on the 70cm band requires robust amplifier design, a challenge addressed by this project featuring the GS-23b / 4CX1600U Svetlana tube. The resource details the construction of a high-power UHF amplifier, providing insights into component selection and layout necessary for stable operation at these frequencies and power levels.

BI5D The archipelago of Dongtou.

The Icom AH-4 autotuner operates efficiently across multiple HF bands, providing seamless automatic tuning for antennas from 3.5 MHz to 54 MHz. Its robust design allows for outdoor installation, making it suitable for field operations and fixed stations. The unit interfaces with Icom transceivers via a control cable, enabling automatic band switching and tuning. The AH-4 is capable of handling up to 120 watts of RF power, ensuring compatibility with most amateur radio setups. Its weather-resistant casing and compact form factor make it a versatile choice for operators requiring reliable performance in diverse environments. Field tests demonstrate the AH-4's ability to maintain low SWR across its operational range, enhancing signal quality and transmission efficiency. Compared to manual tuners, the AH-4 offers significant time savings and ease of use, particularly in rapidly changing band conditions. Its integration with Icom radios simplifies operation, eliminating the need for manual adjustments. The autotuner's performance is consistent with other high-end models, providing a cost-effective solution for amateur operators seeking dependable tuning capabilities without sacrificing performance.

DXpedition to Kubbar Is. (AS-118)

A new multi-mode QRP radio beacon built around the Arduino. The beacon started with the usual lash-up on the bench, hooking the previously reported Wotduino and DDS Shield up to a driver and a transmitter module, as previously used for the Raspberry Pi beacon

The K2 bicycle mobile project

A moxon antenna for 2 meters band featuring 6 dBi and a F/B of 30 dBi

Learn quadrature modulation through interactive flash programs. These programs will allow you to learn about quadrature modulation and quadrature demodulation without getting overwhelmed by math.

A vehicle mounted portable antenna mast.

A dual band delta loop antenna resonating on 30 and 40 meters band using a single wire for the top slopers on both 30 and 40 meters and does not need any balun

A high quality broadcast transmitter big enough for a medium town

This is a collection of emails collected over time which indicate how to put some mods into your Sierra transceiver. Most of the mods have to do with improving the power output.

Ham radio wire antennas are the most common form of antenna used by ham radio operators. Here you can find hints and tips on diy wire antennas

This program converts an ADIF report file from ARRL's Logbook of the World (LoTW) to comma-separated value (CSV) format so that it can be read into a spreadsheet program like Microsoft Excel.

By I0GEJ Weblog - Lidio Gentili

This project describes the construction of a real CW QRP keyer with a small microcontrolle

Signal source circuit for 2.4 GHz by sv1bsx

A collection of modifications and improvements to the Ameritron ALS-600 ham radio RF power amplifier

A sweep generator that produces a sawtooth waveform which sweeps the oscilloscope beam from left to right via its X input, and simultaneously the VCO frequency.

TenTec Receiver RX 320 D Review by DF9CY

An amplifier made using an old HT-41 Hallicrafters Amplifier and adding the 160 meters band By W4NFR

Collection of several Crystal Radio receiver circuits with schematics diagrams and pictures

The m0xpd keyer project utilizes a PIC16F628A microcontroller, offering Iambic A and B modes, adjustable speed from 5 to 40 WPM, and variable weight control. It incorporates a sidetone generator with adjustable frequency and volume, along with a PTT output for transceiver control. The design includes a 16-pin DIL IC socket for the PIC, a 3.5mm stereo jack for the paddle, and a 3.5mm mono jack for the PTT output. Powering the keyer requires a 9V DC supply, which is regulated down to 5V for the PIC. The circuit board layout is designed for through-hole components, facilitating home construction. A detailed schematic and a parts list are provided, guiding builders through the assembly process. The project also discusses the firmware programming for the PIC16F628A, essential for the keyer's functionality. Construction details cover component placement and wiring, ensuring proper operation. The keyer's compact size makes it suitable for portable or shack use, providing a reliable CW interface.

Setting up HF10 a solution for those having limited locations and wanting a low visual impact aerial by G4LDS

Meetings Schedule, study groups, circulars from the radio communication division at ITU

A simple accessory for a satellite station, that allows using a 6 meter capable radio in conjunction with a typical S-band to 2 meter converter

Wiring a Balanced Microphone to the TS-590S Unbalanced Microphone Input

The HarRe antenna series, multi element quarter wave resonant broadcaters band receiving antenna

Decoding multiple Morse code signals automatically on a noisy RF band

Complete guide to receive weather satelite images with a RTL SDR dongle and free software

The 80 metre fox-or/test transmitter is a small low power transmitter which is designed to be used as an alignment aid for running up 80 metre foxhunt or ARDF receivers. It is also usable as a micro transmitter for fox-or-ing events.

Report on tests done on VHF Radios to understand which are best suited for 144 MHz operation in large signal environments like VHF contests

link7 is a Windows 9X program to download/upload data from/to the Kenwood TH-D7.

This page describes how to set up RaspBerry Pi Linux system with already configured AX.25 softwares on SD or micro SD cards

A full superhetrodyne SSB fox hunting receiver kit

FT-847 PA Mod, there is a better way, by G0MGX

Introduction digital atv in the 70 cm band

OM3CPH Universal HAM radio/generator DDS Unit with AD9850 or AD9851

Q15X25 is a packet modem with a KISS/AX.25 interface designed for HF transmission of AX.25 packets and TCP/IP using Automatic Repeat reQuest (ARQ) and forward error correction (FEC).

Kenwood TS 990S, Military Auxiliary Radio System modification

A spectrum analyzer based on ATMega8 microcontroller and a CYWM6935 within a Nokia mobile phone case.

Using NEC4WIN for Jpole antenna modeling

Connecting rhythm and language with Morse Code by Phil and David Tulga