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Victor amateur radio association (w2vtm) Camden, NJ

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.

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.

Designing and constructing a two-element receiving loop antenna array for HF operation involves specific considerations for achieving high directivity and noise reduction. This resource details a homebrew system comprising two 30-inch diamond-shaped loops, spaced 20 feet apart, which are fed through mast-mounted preamplifiers and passive signal combiners. The operational principle relies on adjusting phase delays between elements via precise _Belden 8241_ coaxial cable lengths, optimized for specific bands from 160m to 20m. Performance data, derived from _EZ-NEC_ modeling, illustrates consistent 90° azimuth-plane beamwidth and low take-off angles across the target bands, with _Receiving Directivity Factor_ (RDF) values comparable to a 300-foot Beverage antenna. The article presents detailed elevation and azimuth plots for 20m, 30m, 40m, 80m, and 160m, demonstrating the array's ability to provide strong response at low DX angles while also supporting _NVIS_ signals. Key components like the _DX Engineering RPA-1_ preamplifier and _DXE RSC-2_ signal combiner are discussed, alongside the importance of impedance matching to preserve antenna patterns. The construction emphasizes self-contained elements that do not require ground radials, offering a compact solution suitable for suburban environments and stealth installations, with a focus on optimizing receive performance independently from transmit antennas.

radio.McDougallsHome.net The Web site and Blog of Amateur Radio Station K7JM. Homebrew, Construction, Operating, and Discussion

J-38 and J-37 key collection

member of the South Texas Balloon Launch Team

A web site dedicated to the voodoo audio crew, a group of ESSB enthusiasts

eHam reviews of the Yaesu FTDX-3000 HF Class line transsceiver bu Yaesu

A 3.2m EME dish project that provides a better performance on 1296 MHz (10+dB sun noise vs. 6dB with my 432 array) and an even better performance on 2304 MHz

Article on 50 Mhz Yagi Antennas stacking by OH1ZAA/NN0Y

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

Site dedicated to 6 meter and VHF

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

How to limit unwanted harmonics from your raspberry Pi radio transmitter by introducing filters.

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

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

Since November of 1998, The Freewheelers Net has been on the air on 3.916 MHz

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.

PropNET is an ad-hoc 2-way (and potentially, "more-way") RF-based digital communication network whose activity is reported on the Internet. As participating stations periodically ID and exchange data, they report their activity to an Internet data-collection hub for presentation through this web site.

Clay County Missouri

This software is an amateur radio utility for the lookup of an FCC issued Amateur Radio Call Sign. Run on Windows Linux and MacOSX

HAM radio amateur pages, Jirka from Praha, Czech Republic

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.

2-Meter Weak-Signal Enthusiasts

The elgin amateur radio society Illinois

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.

A 70 MHz Transverter project with a block diagram and schematics

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

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

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.

Discussion of radio equipment made by Kenwood

RACES Repeater for Bucks County, Pennsylvania

Search KH1/KH7Z Log online

LDE articles and reports about long delayes radio echoes by DF5AI

Links and postal addresses of some QSL Bueraus

Hawaii Amateur Radio Club

This is a page to detail how I remotely operate my Elecraft K2 HF transceiver via my home network. The method used should apply to pretty much any amateur transceiver that can be controlled by serial port.

N4ZOU Article on AMTOR mode on eham.net

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

Boardman, Ohio

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!

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.

Oakland county amateur radio society

Online variometer calculator by IN3OTD

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