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A homebrewed antenna for 2m handheld radios by TB1BIG

Presents a QRP AM/CW transmitter project specifically designed for the 10-meter band, utilizing a crystal oscillator and a collector-modulated AM oscillator. The design employs a 2N2219(A) transistor in a Colpitts configuration, generating 100 to 350 mW of RF output power depending on the 9-18 Volt supply voltage and modulation depth. Frequency stability is maintained by a 28 MHz crystal, with fine-tuning possible via a Ct1 trimmer capacitor for approximately 1 kHz adjustment. The resource details the RF oscillator stage, implemented with a 2N2219 NPN transistor, emphasizing frequency stability and low power dissipation. It also covers the amplitude modulation stage, managed by a 2N2905 PNP transistor, which impresses audio information onto the carrier. Selective components (C3, C4, C7, C5) enhance voice frequencies within a +/- 5 kHz bandwidth, and modulation depth is controlled by R2 and R3. The project includes a 3-element L-type narrow bandpass filter (Ct3, L3, C10) to suppress harmonics and ensure a clean output signal. The project provides a complete schematic diagram, a comprehensive parts list including specific capacitor, resistor, and inductor values, and construction notes for the coils (L1, L2, L3). It also offers practical advice on enclosure requirements, suggesting an all-metal case or a PVC box with graphite paint for RF shielding. Operational parameters such as current draw (27mA@9V to 45mA@16V) and input impedance (50 Ohms) are specified, alongside guidance on antenna matching and the importance of a valid amateur radio license for 10-meter band operation.

This is a "techie" site, dedicated to presenting service manuals, parts lists, schematic diagrams and other information of value to restorers and technicians who try to keep these radios working

This Forum is use to discuss the monitoring of the Lehigh Valley, PA

A simple simple sweep generator circuit design where the sawtooth is generated by the PNP transistor and a 555

Home made twin paddle morse code key designed by Steve Taylor G4EDG.

A graphical add-on package to monitor seti@home activity that may be running on multiple computers over a network or multiple instances on the same computer. Runs on Windows or Linux.

This is an experimental CW transceiver for 80m, although the same idea will work on all HF bands

1296MHz M57762 * 16 Power AMP 16V 100A 1.6KW Input

Homemade hamstuf, mostly homebrew antennas in Dutch

A home made antenna tuner based on the W6JJZ basic concept that ,atches balanced loads without the use of lossy baluns, can provide band-pass filtering and harmonic attenuation.

A 2m 70cm Dual Band J-Pole antenna for 35 USD. An excellent performing J-Pole type antenna, constructed from readily available materials.

The Baja Net is one of the boaters favorite nets on the West Coast. It has a long history of handling traffic for mariners who are out of touch with friends and family. Several stations have phone patches enabling them to put you right on the line to talk to your loved ones.

This is a SSB and CW transceiver for the 80m and 20m bands. It produces 25 Watts out and uses a digital frequency display.

One of just a few webpages for the magic band, see it from the german point of view.

Information about our local Echolink Node #1224, on Long Island NY

This article by Seabury Lyon, AA1MY describe how homebrew kits for amateur radio pourposes, in order to support wire antennas

Decoding NOAA APT weather satellite images is achieved with a homebrew receiver and a Turnstile Cross Dipole antenna, feeding data to a Pentium-3 500MHz PC running Windows XP and the WXTOIMG program. This setup, operated by VU2IIA in Mumbai, India, focuses on capturing and processing signals from NOAA satellites to generate visual weather data. The blog documents the technical aspects of constructing the receiving station, including antenna design and receiver integration. It provides insights into the practical challenges and successes of amateur satellite reception, specifically for Automatic Picture Transmission (APT) signals. Operational details cover the software configuration and image processing workflow necessary to transform raw satellite data into usable weather imagery. The content serves as a practical guide for radio amateurs interested in satellite meteorology.

Activating a county for ham radio can be dangerous to your health!

A 5 elements homemade DK7ZB yagi antenna for 4 meters band based on a 50MHz TONNA

Demonstrates the adaptation and construction of a 7-element DK7ZB Yagi antenna for the 4-meter band (70 MHz), utilizing components from a defunct 2-meter CUE DEE Yagi. The resource details the modifications made to the original DK7ZB design to fit the shorter CUE DEE boom length, specifically adjusting element lengths for 6mm rod elements while reusing existing mounting holes for the reflector and last director. It provides precise element lengths for the reflector, dipole (12mm aluminum tube), and five directors, along with a note on cutting elements for transport. The article includes a 4NEC2 simulation file for performance analysis and an SWR plot, confirming the antenna's electrical characteristics. It also specifies the calculation for the quarter-wavelength matching cable using SAT752F coaxial cable, resulting in a 909mm length. Practical application is shown with the finished antenna in operation at JO20XC, listing several activated Maidenhead squares such as JO56PA and JP40KS, validating its effectiveness for portable 70 MHz operations.

"W2IK's Personal experience being the first responder at ""ground zero"" during the WTC 9/11 disaster."

ATV 432 MHz AM transmitter schematic

Home Made CW paddles made from a printed circuit board and a teflon mounting block while contacts are made with simple brass threaded rods.

A full galvanic isolation interface for digital modes tested with FT-847

Homemade Loaded Coil Dipole ( w8010 diamond ) for 10, 15, 20, 40 and 80 meter

Using patch antenna for amateur radio reception of the 13cm band with a sample 2.4 GHz LHCP patch antenna by K3TZ

The X80 multi-band HF vertical antenna, a commercial iteration of the Rybakov design, exhibits a physical length of 5.5 meters, or approximately 18 feet, and is constructed from aluminum tubing. It operates as a non-resonant vertical, requiring an external antenna tuner for impedance matching across its intended operating frequencies. The antenna's design incorporates a 1:4 UNUN at its base, facilitating a nominal 50-ohm feed point impedance for the coaxial cable. Performance observations indicate effective operation on 40 meters, 20 meters, 15 meters, and 10 meters, with reduced efficiency on 80 meters and 160 meters due to its relatively short electrical length for these lower bands. Comparative analysis with a G5RV dipole and a half-wave end-fed antenna reveals the X80 offers a lower take-off angle, beneficial for DX contacts, particularly on the higher HF bands. Field tests conducted with an Icom IC-706MKIIG transceiver and an LDG AT-100ProII autotuner demonstrate the X80's ability to achieve acceptable SWR across 80m through 10m. The antenna's compact footprint and ease of deployment make it suitable for restricted spaces or portable operations, though its performance on 80 meters is noted as a compromise compared to full-size resonant antennas.

Cabrillo2Adif A software for converting the radio logs from Cabrillo to Adif log format (for Mac OS X)

Amatuer Radio QSL Cards. Full Color QSL and Eyeball Cards

Article by VU2GT about VHF antennas, how to evaluate performances and models.

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.

Construction of attenuator, suitable for fox hunts at 144mhz

Software Defined Radio manufacturer, SDR-IQ NetSDR SDR-IP and IF-2000

A simple 50 ohm dummy load to test transmitters. includes a simple RF diode detector to measure the peak voltage, and calculate the power

An indeal stealth antenna made by multiple quarter wave verticals, supported by a tree.

Homemade Jeep Tailgate Antenna Mount for use with a Swing Out Tire Carrier

A Weather ATV Repeater project I am currnetly working on.

Homebrew GMRS 3 Element Yagi yagi for 462-467 MHz

Project with pictures and plans for an HF off center fed dipole by KB1NWH

10.100 - 10.140 MHz 3 Watts output by 7n3wvm

The Rolling Home Ham Radio on the Road

2 transistor transceiver for 28MHz CW

Homebrew Solar Panel 60Watts. Building a homemade solar panel from solar cells that would have otherwise been thrown out.

The Providence Radio Association Incorporated, one of the oldest radio associations in the world.

On these pages you will find articles and pictures reagarding a renewed Drake TR7 by DK4DDS

The Speaky HF SSB transceiver and other homebrew projects Homebrew of radio equipment, antennas, tuner, etc.

Magnetic Loop Antennas for The Radio Operator with Limited Space, a two part series of articles on how to construct a magnetic loop antenna, including directions on selecting high voltage tuning capacitor

70 MHz transverter, 4m band, by G3XBM

Schematic of a homebrew receiver and keying