trap design

A turnstile antenna for 2-meter ARDF - Antenna design for use with hidden transmitters on international-rules ARDF events

A 6m portable 4 element quad - This antenna is based on a design for a portable 2 element 6m Quad by VE7CA, which is featured in the 19th Edition of the ARRL Antenna Handbook

PAC-12 Antenna - mobile multiband  ^pop - Here’s an award-winning, easy-to-homebrew, multi-band portable vertical antenna designed by long-time antenna aficionado James Bennett, KA5DVS. He’s documented the design and construction plans for a portable antenna that can be built with relatively ordinary components

Types of multiband antennas - Types of multi-band antennas for the HF bands, from the horizontal end fed wire, to g5rv, log periodics, trap dipoles, vee beams and rhombic antennas.

N4EKV.COM - Antenna Tuners - Homebrew balanced-L antenna tuner. Covers 160-10m. Designed specifically for balanced feedlines.

PAC-12 Vertical portable antenna - Build the PAC-12 Antenna a multi-band portable vertical designed by KA5DVS, here’s an award-winning, easy-to-homebrew, multi-band portable vertical antenna designed by long-time antenna aficionado James Bennett, KA5DVS. He’s documented the design and construction plans for a portable antenna

Helical Antenna for 2.4 GHz and 802.11b - The following page details construction of a Helical antenna based on the superb design by Jason Hecker.

Planet Ham - Planet Ham is a website designed to aggregate blogs produced by Amateur Radio enthusiasts. The aim is to provide a central directory of Amateur Radio blogs so that interested browsers can visit subscribers sites and read about the various aspects of the hobby in detail

MicroSignals - MicroSignals produces a line of RF and IF signal processing components that offer high performance at an exceptional value. To achieve this MicroSignals began with an engineering team that possessed an excellent background in RF Transformer and Balun design.

Otto engineering - Otto engineering is comprised of two divisions otto controls and otto communications. otto controls designs and manufactures a full line of switches and grips used in heavy equipment, aerospace, marine, medical and other demanding applications. otto communications designs and manufactures audio accessories for two-way radios used in public safety, police, fire, retail, hospitality manufacturing and other markets.

Peter W. Dahl Co. - Custom transformers by Mr. Dahl has been designing specialty transformers and reactors for over 35 years, and has been a licensed Ham radio operator, K0BIT, since 1955.

Starline Electronics - Full-size Professional Circumaural (closed type) Stereo Headphone Monitor designed for studio use, swl and amateur radio.

Rotating Tower Systems - Using our components you can build a rotating tower with greater capability than 3-4 static towers. A rotating tower allows common rotation of HF stacked arrays, VHF and UHF arrays, and antennas mounted at optimum heights. Component design also allows tower shunt loading and end support for wire antennas

Q15X25 - Q15X25 is a packet modem with a KISS/AX.25 interface designed for HF transmission of AX.25 packets and TCP/IP using Automatic Repeat reQuest (ARQ) and forward error correction (FEC).

JT65 - JT65 is a digital protocol intended for Amateur Radio communication with extremely weak signals. It was designed to optimize Earth-Moon-Earth (EME) contacts on the VHF bands, and conforms efficiently to the established standards and procedures for such QSOs.

Qsl factory - qsl cards - Qsl card printer and designer offering truly original styles of quality single and double sided color qsl cards, both ready-made and custom.

RadioLabs - Radio, Wireless and Beyond - Specialize in engineering, design and repair of all rf equipment. Dealer for two way radios, scanners, shortwave radios, wi-fi antennas, wifi amplifiers. Based in Fortuna, California.

Ham Gear - Ham Radio T-Shirts, Caps, Mousepads, also vintage designs! Designs include logos from Amperex, Collins, Eico, Eimac, Gonset, Hallicrafters, Hammarlund, Heathkit, Johnson, Knight, Mars, National, Swan, Skywarn and others.

Duncan's Amp Pages - This is an internet resource for those interested in guitar amplifiers, vacuum tubes, and design tools such as SPICE modelling.

Delabs technologies Product Design and Engineering - Around 200 electronic circuits in pdf format or images, There are also over 1000 links to useful electronics, freeware, open source websites. There are some 100 useful documents, software and pcbs too. Mainly industrial electronics, instrumentation. Covers Various aspects of electronics and basics of circuit design.

QST signalink review - SL-1 - Designed to handle audio signal interfacing as well as transmit/receive switching Reviewed by Steve Ford, WB8IM

Grounding and RFI - Described system was designed to provide a high level of lightning protection - there are three levels of defense to guard against let-through. It isn't perfect, but does, however, follow good guidelines and shows measured improvements in RFI reduction.

The smk-1 on 20m - Taking the venerable SMK-1 design to 20m and adding an RF amp, audio filter, and a TiCK Keyer ... by Wayne McFee, NB6M

Are you ready for BPL - Broadband over power lines (BPL) is a technique for transmission of high speed data (broadband Internet) over powerlines. Access BPL technology injects radio frequency energy into powerlines which were not designed for transmission of radio frequency energy, and leak substantial energy that causes interference to radiocommunications service

Rainbow Antenna Analyzer - A small and inexpensive measurement device designed to determine antenna performance across the amateur bands through use of automatically collected SWR readings