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A transmitter project for the 136 kHz band by IK2PII

Constructing a basic multimeter involves integrating a 0-1mA meter movement with various shunts and multipliers, selected via a switch, to create a versatile instrument capable of measuring DC volts, current, and resistance. The design outlines two main units: a primary unit handling six DC current ranges up to 1 amp and eight DC voltage ranges up to 1000 volts, alongside an internal battery for an ohms range up to 200,000 ohms. This approach allows for a practical, hands-on understanding of meter operation. An add-on unit further extends the multimeter's capabilities, incorporating a meter rectifier and switched series resistors to provide four AC voltage ranges up to 100 volts. Additional shunt and series resistors, designated Ra and Rb, are included to expand the instrument's range to 10A and 5kV, demonstrating how modular design can enhance functionality. When this add-on is in use, the main instrument is set to measure 1mA FSD, connecting via specific lugs. Component selection emphasizes precision, with 1% tolerance high stability resistors for series elements and Eureka resistance wire for shunts. The design specifies values calculated for a meter with 60 ohms internal resistance, noting that these would require modification for different meter characteristics. Experimental adjustment of shunt values is recommended to ensure accurate readings against a calibrated reference meter, reinforcing practical calibration techniques.

Article on 50 Mhz Yagi Antennas stacking by OH1ZAA/NN0Y

The purpose of the Marconi Amateur Wireless Society is to encourage experimentation in all aspects of amateur radio in a spirit of friendship and goodwill.

member of the South Texas Balloon Launch Team

An SDR project, MDSR modulator-demodulator software radio, made using an inexpensive converter and a pc. MDSR has a transceiver and a receiver converters.

Site dedicated to 6 meter and VHF

The Tri-City ARC was formed by amateurs in the New London, Norwich and Westerly areas (hence Tri-City) desirous of forming an association of local amateurs with the purpose of furthering better cooperation among amateurs

A small rig that you can take hiking and on business trips.

Summits on the Air South Africa formed in October 2002 to draw up an Association Reference Manual and compile a list of South African summits that can be activated or contacted for SOTA awards

Clay County Missouri

Sort of similar to the one of the 6m omni. Instead of using twin-lead, this design makes use of a more or less regular double bazooka antenna (coaxial dipole). Your attention shall be drawn to the available standart literature, such as Rothammel. In order to "compute" the dimension, Karl Rothammel mentioned that the total length of the dipole shall be 95% of the free-space wavelength. The short-circuit bridges (closing the folded dipole) are to be placed at a distance-fraction being equal to the velocity factor of the coax cable used, which will be 66% using RG-58 or RG174.

Developing operational amateur radio equipment for the 134 GHz band presents significant technical challenges, particularly in frequency generation and stability. This resource details the construction of a 134 GHz system, outlining its architecture with separate transmit (Tx) and receive (Rx) modules, each employing a local oscillator (LO) and RF head units. The system utilizes a dual Flann 50 GHz lens-type horn antenna configuration for optimal signal coupling. The transmit path incorporates an LMX2541 synthesizer chip operating at approximately 2.8 GHz, referenced by a 10 MHz double-oven Morion OCXO for exceptional stability. This signal is multiplied through a series of stages (X4, then X2) to generate a 22.4 GHz signal, which subsequently drives a dual series diode multiplier to produce the final X6 signal for 134 GHz operation. The receive side features an anti-parallel diode mixer coupled to a 144 MHz transceiver via a preamplifier, ensuring effective downconversion. Operational mode is CW, achieved by keying a multiplier stage. The project includes images of the Tx and Rx head units and describes a successful 3.5 km test with G8ACE, demonstrating stable signal tones due to PLLs locked to OCXOs at both ends, confirming the system's robust performance.

IOSA, Hillwalking etc

HAM radio amateur pages, Jirka from Praha, Czech Republic

Summits on the air, sota. an exciting new award scheme for radio amateurs. the scheme encourages lightweight portable ham radio operating in mountainous and wilderness areas areas.

The elgin amateur radio society Illinois

Open to employees and retirees of Avaya Inc. in Lincroft NJ. As Avaya Inc. was spun off from Lucent Technologies, AT&T Bell Laboratories, and even Western Electric

RACES Repeater for Bucks County, Pennsylvania

Warszawa 2000 Award, Mazowsze (Mazovia) Award, Vistula) River Award, All Baltic Islands Award, Maritime Mobile award, Baltic Sea lighthouses award

Greek Lighthouse Award has been instituted by the Northern Greece Contest Team and will be issued to any Ham Radio operator or SWL for QSOs with (or reports from) amateur radio stations operating from Greek's lighthouses.

An home made antenna switch with a Dummy Load selector. If you forget the radio is connected to the open or grounded side of the switch and you try to transmit, it is very easy to damage the finals of your transceiver.

The Big Dog contest club is a group of amateur radio enthusiasts who enjoy the fine arts of radio contesting and consuming fine foods but not necessarily in that order!

Links and postal addresses of some QSL Bueraus

Boardman, Ohio

Sydney Amateur Radio Club, Sydney NS, Ham Radio in Cape Breton, IOTA NA-010, Nova Scotia

A 3CX1500/A7 8877 144mhz W6PO amplifier, that running a little over 4kv on the plate, this Amp will do over 2kw out.

6 meter beacon from Monselice Italy JN55VF

Radioklub Nokia is the Amateur Radio Club Station for Nokia employees and family in the Dallas - Fort Worth area in Texas, USA.

Online variometer calculator by IN3OTD

Oakland county amateur radio society

Ham radio station in Aruba P43E

Lighthouse list, dx peditions, pictures and awards issued

Measuring noise fiugre on the W2IMU horn and the dual-dipole-feed

This group is located just north of Reno, Nevada and primarily uses simplex frequencies.

Quinte West, Ontario, Canada

Replacing a new VFO know to elecraft K2

Personal webpage of AE7XQ with information for those starting out in amateur radio and those who are interested in CW and QRP.

A home made magnetic loop for HF Bands. This small and compact loop is designed to support small power transmissions on HF bands, from 7 MHz to 21 MHz

DF0WD DL4YHF Longwave Station include a linear transverter and antenna tuner

The Triple A Amateur Radio Association (TAARA) is identified as an ARRL-affiliated Special Service Club, operating within Beaver County, Pennsylvania, approximately 28 air miles northwest of Pittsburgh. The organization provides a community hub for amateur radio operators in its service area, focusing on local engagement and support for the hobby. While the QSL.net hosting platform indicates a 404 error for the specific page, the club's stated affiliation with the _ARRL_ and its designation as a _Special Service Club_ suggest a commitment to public service, education, and promoting amateur radio. Such clubs typically engage in activities like license classes, field day operations, and emergency communications support within their local communities.

Bloomfield Amateur Radio Club Connecticut

The Linux operating system is perhaps the only operating system in the world that can boast native and standard support for the AX.25 packet radio protocol utilized by Amateur Radio operators worldwide. This document describes how to install and configure this support.

Employees and retirees of General Motors Corporation