direction finding circui

Squalo 6M horizontal omni antenna - An almost Omni directional horizontal antenna for six meters by G8UBJ

Single Coil Z Match - Single Coil Z Match, circuit Diagram and homebrewing notes

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

Getting the most from your tuner - Here is how to adjust this popular tuner circuit so it transfers maximum power to your antenna without going snap

A remote antenna tuner - Interesting project to remotely control, using a servo control circuit, a common commercial antenna tuner by N30X

Fun With Tubes - A noncommercial site operated by Max Robinson and dedicated to passing on and preserving knowledge of vacuum tube circuits and techniques.

Antique Radio Schematics and Capacitors for Tube Radios - Specializes in antique radio schematics and capacitors. carries antique radio schematic diagrams and electronic circuit service information for american, canadian and european antique radios.

Antenna Authority - Specializing in an assortment of directional, wideband antennas and other equipment used for radio location

RF HAMDESIGN - An engineering oriented organization specializing in the design and manufacture of high performance parabolic antennas, 3dB high power RF couplers, Antenna power splitters, directional RF couplers and more items for RF transmission from HF through Microwave frequencies.

E. H. Armstrong - Radio's premier inventor, Edwin H. Armstrong was responsible for the Regenerative Circuit (1912), the Superheterodyne Circuit (1918), the Superregenerative Circuit (1922) and the complete FM System (1933).

A new method of radio direction finding Priority listing - A method of finding radio sources with antennas based on omni-directionality (the less directional the better coverage). Uses energy levels and some sophisticated math (encompassed in a free software download on the site) to find x,y,z coordinates of the fox relative to the center of your antenna array. Can be overlayed on a GPS map to help you locate in real-time.

ARDF transmitter for 80 meters - The 80m TX described here is the well known ON7YD ATX-80 and timer, combined and re-engineered to fit a readily available enclosure by G3ZOI

Improving Heathkit SB-220 - Circuit Improvements for the Heath SB-220 Amplifier

Circuit Improvements for the TL-922 - by Richard L. Measures, AG6K

Meter Mate - SWR Graph Software - Meter Mate is a companion utility for your directional watt meter that allows you to calculate the SWR reading when the forward and reflected power readings are measured. In addition to calculating the antenna system SWR Meter Mate will also plot the SWR curves of all of your antennas onto graphs that may be printed out.

MU-Locator - This free program displays the location of any locator on a map. It calaculates between two Maidenhead locators the distance (km and miles) azimuth longitude latitude Show the location, direction and distance as you move your mouse on a map! Graphical Locator Program, By ON6MU

Heathkit SB-200 Modification - Tuned input circuit modification by Tom Boza - NE7X

Negative feedback output circuit - Negative feedback is often referred to as shunt feedback in conjunction with emitter degeneration.

A simple VOX circuit - Here is a 3 transistors 6 diodes circuit that is a Voice Operated Tx PTT control as well as an ANTI VOX circuit to stop mis-operation from Rx noise by G8MNY

Morse Code Beacon Keyer - This circuit stores a single morse code message as bits in an EPROM chip, the message is sent to a relay which can key a CW transmitter.

Improvements for TS-830S - Circuit Improvements and Maintenance Procedures for the TS-830S

Circuit Improvements for the TS-430S - by Richard L. Measures, AG6K

Homebrew FT 817 Headset - A simple circuit to homebrew your own headset for the Yaesu FT-817

External Keypad for FT-817 - An external keypad for FT-817(ND), for the serious portable/field-day contester/operator. Homebrew it with the free firmware and public circuit diagram. The circuit is very simple and takes power supply from the ACC port of the radio

A regenerative receiver with 6SN7GT - Circuit to build a regenerative receiver