direction finding circui

A 144 MHz turnstile antenna - Omnidirectional and horizontally polarized VHF antenna

3 elements Yagi for 50 MHz - 6 Meter Direction Agile 3 Element Yagi Antenna

The 4X4 Slimtenna - Development of the Slim Jim antenna for HF

About directional antennas - Directional antennas a beginners explanation

Discone antenna - About the basics of what is a discone antenna for wide band or bandwidth omnidirectional applications

Cookie Cantenna Wi-Fi - Make a cheap, portable, high performance (15-18 db) directional antenna out of commonly available parts that can be purchased in most grocery and hardware stores.

The HANDI-Finder - This Radio Direction Finder Device Connects to an FM Receiver, Transceiver, or HT

N6QAB Radio Direction Finding Web Site - Samples and documentation on RDF setups

Radio Direction Finding - The Utah Amateur Radio Club - Radio Direction-Finding RDF

Adding 160 meters to the Heathkit SB-220 - There will be radical changes to this Heathlit SB-220. There will be the addition of 160 meters along with many other circuit and design changes.

Omnidirectionnal antenna for the 23 cm band - Building an omnidirectionnal antenna for the 23 cm band

Transistor PA Biasing - Here is a simple circuit that can deliver the peak base current needed for linear ssb operation

Integrated Circuit Audio Amplifiers - Circuit designs for IC audio amplifiers by N1HFX

Design Guidelines for JFET Audio Preamplifier Circuits - Design Guidelines for JFET Audio Preamplifier Circuits By Mike Martell N1HFX

Adjustable Regulated Battery Charger - This battery charger circuit is regulated and adjustable to make this circuit able to charge the mosto NiCAD battery.

The express-pizza antenna - Build a directional antenna for the 1.2 GHz band, in 15 minutes

RF Dummy Load - The use of dummy load is mandatory for off-air adjustment of the transmitters. Build one.

DC RF Sensing PA Switching - Circuit for dc/rf sensing pa switching from g8mny

Noise Bridge Tuner Tuner - Noise bridge circuit to tune your tuner

QLF Filter - Microprocessor based interface designed receives a signal from a Morse key, processes it, and re-transmits it to the radio. A microprocessor in the circuit is pre-programmed with a proprietary algorithm which makes a number of measurements and adjustments to the less percise human generated code.

A low cost morse Trainer / Keyer - By Prof. T. K. Mani - VU2ITI

FT290 CW KOX Circuit - This is not actually break-in but just KOX circuit. It can only be used on the CW mode otherwise it keys up the Tx

Non-relay instant RF Switching - Coax lines to do the RF switching. The advantages are instant switching, no power wasting DC control circuits.

An Accurate Power Meter For QRP Ops - A circuit using two junkbox transistors and a garden variety op-amp that will let you accurately measure your rig\'s flea power down to milliwatts.

Oscilloscope Tester - Circuit to assist in the setting-up and calibration of oscilloscopes