circuit design

2 Meter 10 Element Quagi Antenna - This antenna was designed by N6JSX Kuby for Transmitter hiding. Fitting the requirements of directionality, high gain, and portability. This antenna was derived from the ARRL Handbook information on Quagi's and Yagi's; in the absence of two meter Quagi information, UHF Quagi dimensions were scaled into 146 MHz use.

Quagi and Yagi on 2 Meters  ^updated - Designing quagi and yagi antennas on 2 Meters, some preliminary notes by Cebik, W4RNL

Six Meter Wavelength Band Antennas - Why 6 meter hams design the best antennas

The J-pole Antenna Revisited Yet Again - The dynamics of antenna design

Loop Antenna Design - Full-wave loops are very popular antennas. They are especially useful on 80 and 40 meters where they perform well at modest heights

HF Mobile Antenna HB9ABX - Most efficient hf mobile antenna, This mobile antenna is designed for all HF bands from 10 to 80 meters an proved to be very efficient in my travels in South America on 15 and 20m for contacts to Europe and within South America.

An automatically tuned 7-30MHz mobile antenna - This is a base-loaded vertical antenna that mounts on the car's roof. The loading coil is designed as a variable inductor, with a three-legged chariot that travels up and down inside the coil, with grooved brass wheels running on the coil turns, and driven by a slotted rotor tube.

Quagi Designer - Quagi antenna design, this little windows application let you calculate dimensions of elements and spacing of a quagi antenna. Freeware by VE3SQB

A homebrew 10-element 900 MHz quagi - A 10 elements quagi antenna for 900 mhz

2m Quagi Antenna plan - A design of a 2 m quagi antenna by TA2IB

K5OE, 70 cm Quagi Antenna - An AO-10 antenna by K5OE, this design is optimized for 436.8 mHz with a 50 Ohm feed

Optimizing Inductors - While intended mainly for antenna loading coils, this article also applies to other resonant systems, such as amplifier tank circuits.

CSVHFS Antenna Gain Measurements - The Central States VHF Society has conducted Antenna Gain Measurements since its inception in 1967. Comparisons between commercial and homebrew antennas, between different homebrew designs, and between different commercial designs. Mostly VHF UHF and up antennas.

Crank-up Tilt-over Tower  ^pop - A home made tower, with project design and pictures

Coaxial Traps for multiband antennas - A new perspective on the analysis and design of this popular antenna element. By Karl-Otto Müller, DG1MFT

2.4GHz Cubic Quad Antenna  ^{updated  pop} - The Cubic Quad antenna is a commonly homemade antenna in the range of about 150 odd MHz. Our little project was to design one of these for use in the 2.4GHz range for 802.11 wireless LANs.

Tennamast - Tennamast design and manufacture a wide range of fabricated metal goods, Antenna masts, Wind-sock masts, and masts for holding such systems as CCTV, Loudspeakers, Lighting units

Tarheel Antennas - Our motorized antennas and stainless steel mounts are designed with the most avid HAM radio operator in mind, as well as commercial applications. They are made with the best materials and top of the line workmanship. Antenna mounts

Communication Concepts, Inc. - Provide components to the amateur who wants to construct their own gear and to the professional who wants to save money and time in prototyping their circuit design, Filters, HF Amplifiers, Splitter Combiners, VHF Amplifiers, ATV

Intuitive Circuits, LLC. - Intuitive circuit llc is a market leader in dtmf encoders and decoders, cash register surveillance, cash register security, and text inserter products. Amateur televisions ATV products

microHAM - Supply high quality accessories for your ham shack, including Band Decoders, various types of Antenna Switches, Antenna Stacking devices, special devices designed for the SO2R operator, USB Interfaces, Digital Mode Interfaces, Keyers and many others

Circuit Specialists - We specialize in pc-based data acquisition systems, test equipment, electronic components, disk on modules, choke and coils, diodes, capacitors and connectors, potentiometers, crystals, resistors, relays

Technical resources for design engineers using batteries and power supplies. - Resources for custom battery chargers and power supplies from powerstream

Avoid pitfalls when recharging batteries to ensure long life - Portable design - avoid pitfalls when recharging batteries to ensure long life - secondary batteries can be simple devices, but improper charging can be devastating to the user experience.

Constant Current Battery Charger - Constant Current Battery Charger circuit project