simple 4:1

Limited space Delta Loop - Here is a simple and easy to build antenna in a Delta Loop configeration that should make 10 and 12 meters lots more fun if you have a limited space situation o

Switchable Balun  ^updated - A 1:1 to 4:1 switchable balun by N1LO

4:1 balun project - CVARC 4:1 Balun Project Kit by AE6YC

4:1 coax balun design - Online calculator for a 4 to 1 coax cable balun

Guanella 4:1 balun - This article reviews the proposition that a 4:1 current balun in the style of Guanella can be constructed with both pairs of windings sharing a common magnetic circuit.

EH antenna for 11 meter - A very simple Eh antenna for 11 meter, drawings in english and italian.

Constructing simple wire antennas - Simple wire antennas like dipoles and verticals are dead easy to make: here’s how

Mobile Portable Whip Antenna - A simple base loaded quarter wave vertical, which can be used on a car or portable by G3YCC

I7SWX Coax-Fed multiband antenna - This simple multiband antenna works on all HF bands from 3.5 to 30 MHz, including WARC bands other than 10.1 MHz.

Southeastern Asterisk Radio Networks - Interoperability solutions via Asterisk based RF Gateways - Southeastern Asterisk Radio Network (SEARN) and the Southeastern Asterisk Amateur Radio Netwok (SEAARN) are designed for the purpose of developing interoperability capabilities amongst diverse communications systems. Digital Amateur Radio Project Association - DARPA expanding the digital experience.

Morse Key for iPhone - A free simple touchscreen-based CW Morse Code straight key. Practice sending Morse Code on your iPhone.

Simple Two Position Remote Antenna Switch - w4kaz antenna swicth

Simple beacon construction notes - Here is a simple, self-contained beacon which can run a few milliwatts or as much as a watt depending on choice of amplifier and supply voltage.

Electronic calculator - Some simple electronics calculator in javascript

Bandpass and I.F. Filters - On this page a popcorn highpass filter, some inductors and their Q , double tuned bandpass filters and simple Cohn Crystal ladder IF filters are presented.

A Simple Dual Band SSB Transceiver - Homebrew a dual-band transceiver with a crisp receiver and a clean SSB signal

Tuna Tin 2 - The Tuna Tin 2 is a simple transmitter originally designed by the legendary author and experimenter Doug DeMaw, W1FB. The TT2 was first published in the May 1976 issue of QST.

QRP AM CW transmitter - A simple low-power broadcast-type circuit, using a crystal oscillator integrated circuit and an a collector modulated AM oscillator

QRP transmitter with VXO - This is a nice 1 W QRP transmitter that can be used in combination of one of the simple receivers.

30m CW-Transceiver - GM47: Simple 30m Band QRP CW-Transceiver

CAT programming interface for ICOM rigs - This simple and cost effective interface circuit is designed for use with any ICOM amateur radio equipment with CIV interface

Hear Amateurs on your FM Radio - The idea makes use of a very simple direct conversion receiver on the band of interest.

NHRC-2 Based Repeater Controller - NHRC-2 Based Repeater Controller A perfect controller for a simple repeater or link, or portable/solar powered system.

PC to RTX interface - Interface with galvanic isolated audio and digital paths. For ICOM IC-706, IC-718, IC-746 and IC-756 HF transceivers, the next one suits modern KENWOOD HF RIGs and the third is a simple "PSK-31" interface.

Digital power meter - A simple digital power meter by Dave Roberts, G8KBB