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A simple VHF vertical aerial for the home station

The Olivia transmission system is constructed of two layers: the lower, modulation layer is an (almost) classical Multi-Frequency Shift Keying (MFSK) and the higher layer is a Forward Error-Correcting (FEC) code based on Walsh functions.

Using MFSK mode, 98 Kb PDF doc, taken from QST January 2001

How to adjust your SWR on your radio and why.

PSK31 is a digital communications mode which is intended for live keyboard-to-keyboard conversations, similar to radioteletype. Its data rate is 31.25 bauds (about 50 word-per-minute), and its narrow bandwidth (approximately 60 Hz at -26 dB) reduces its susceptibility to noise.

A portable amateur radio station which the radio amateur can take when asked to go to an event which needs support with radio communication.

Bird Technologies supplier of RF products, like RF Meters, Bird 43, VNA, Spectrum analyzers, attenuators, transmitters combiners, dummyloads, terminators and replacement parts

A High-End UHF Preamp for the VHF/UHF Dongle

Analyzing FCC amateur radio license issuance data, this resource presents monthly graphs and raw numerical statistics detailing the number of new and upgraded amateur radio licenses. The primary focus is on the impact of the Element 1 Morse Code test removal on HF privileges, specifically observing the transition rates from _Technician_ to _General_ and _Extra_ class licenses. Data is sourced from _QRZ Archives_ and processed using a custom Perl script to tally "Issued" licenses each month. The presented data, available in graphical, tabular, and raw XML formats, clearly illustrates the "spike" in General class upgrades following the rule change. It also highlights a consistent rise in new Technician licenses observed in March of both 2006 and 2007. While the dataset currently extends back to January 2006, providing a limited statistical snapshot for long-term Technician trends, it effectively captures the immediate climb in General class licenses.

A Slinky-based doublet or loaded vertical QRP antenna tested for 40 meters band

DF9CY implementation of W1HIS suggestion of inserting a common mode choke into a 40m antennas feed-line.

A radio's transmitting power can be concentrated along the horizon by use of a GAIN antenna. Although you may still be transmitting with four watts of power, your effective radiated powerwill be greatly increased. This table shows the effects of antenna gain on a transmitter with 4 watts of transmit power.

A general guide to D-STAR. The purpose of D-STAR is to allow HAM Radio operators to speak further and clearer using digital voice while sending data from 1200 BPS on up at the same time.

A range of easy-to-build RFI filters by John Regnault, G4SWX

Article on mobile antenna mounting methods by Firestik

Ebook by Akira Matsuzawa Tokyo Institute of Technology, Building blocks in RF system and basic performances, Device characteristics in RF application , Low noise amplifier design, Mixer design and Oscillator design

Yaesu FT-1000MP Mark V Field review by W4TI

Speaker Microphone Pin Out, Dual PTT Switching,Programming Cables, SMA Antenna Connection, Extended Antenna Threads for Baofeng UV 3, UV 5 Series handheld transceivers

A 4 element addition for 10m to an existing 4 element yagi (ZX antennas)

DELTA Technology is specialized in the lightning protection field, surge arresters, lightning counter.

Wide bandwidth Trapped Verticals and rotary dipoles, baluns, 40m/80m wire dipoles and accessories from Australia.

SWR (standing wave ratio), is a measurement of how efficiently your antenna system will radiate the power available from your radio. In simple terms, your radio would like to radiate all of its power, but can only do so if the other components cooperate

An optimized QRP transceiver for 40 meters band

Microphone wiring for Yaesu FT-757 GX II

Solartech Power Inc. manufactures, distributes and sells high efficiency solar panels and wind power turbines.

Nino porcino documentation about CHIP64 digital mode

Green that aluminum into something useful right in your own backyard by WB2CQM

The Remote Control Antenna Switch consists of two circuit boards. The control unit and the remotely controlled switch

Antenna dimension, diagram and simulation of the ZX Antennen ZX 6-6 Yagi for VHF UHF by DF9CY

Measurements for building a full wave loop using wire

Makers of oscilloscopes, spectrum analyzers, frequency counters, power supplies and more testi equipment products

Project of receive only filters optimized for minimal loss and very high rejection of frequencies below 75% of the filter center frequency by K1TTT

We are committed to constantly improving our solutions in areas of GPS System, GPS Receivers, GPS Antennas, GPS Dataloggers, RF Modules, Wireless Security Systems, Automatic Vehicle Location (AVL) for real time and passive tracking

This article contains the measurements for building a full wave loop using wire and length of 1/4 Wave Coax Matching Transformer

SS232K - The simple and safe RS232 interface for Kenwood radios

A small antenna tuner for 14 MHz

An overview of some of the ways, and the key tips on how electronics soldered joints can be unsoldered or desoldered.

The RoadTrek design presents some unique challenges to us hams. Here an example of a VHF and HF antenna installation on a VAN

Competent all-around 2-meter mobile transceiver, review by W4TI

Don't neglect one of the most important parts of your station!

80-meter peilontvanger / receiver includes printed circuit sample and list of components

Some basic antenna information for the newcomer

How to build a phasing harness for stacking antennas

Recepteur decametrique 3 - 30 MHz Detection classique et SDR

Assembling a Code-Practice Oscillator, a PDF by ARRL

Construction of attenuator, suitable for fox hunts at 144mhz

TenTec 1208CY 10/50 MHz Transverter modification by DF9CY

The safe RS232 CAT interface and PA buffer for Elecraft K2

Sams continues the tradition with the publication of new manuals every month, covering the latest in Televisions, including HDTV, Projections TVs, and coming soon, LCD monitors.

General article on Baluns at myantennas.com, what is a balun and when to use baluns