80m trap design

W3FF Portable Dipole  ^pop - This is the antenna w3ff designed for his walking portable station. It is a dipole constructed out of the plastic plumbing pipe CPVC. There are telescoping whips at the ends of each side of the dipole, and these whips are adjusted to bring the antenna into resonance on each of five HF Bands 10, 12, 15, 17, and 20 Meters

Stacked 7-Element-2m-Yagis - These yagis and groups were designed with YO7.23 from K6STI and checked with EZNEC from W7EL. With a gain of 14/17/20dBd they have a good relation between gain and mechanical problems.

80M Vertical antenna with capacitance hat  ^pop - Simple wire antenna cheap to make, using readily available materials, Low angle radiation, with rejection of high angle signals Wide bandwidth, with resonance at the 80M DX window (3.790-3.800 MHz); and Maximum height is 40 feet

Yagi Element Mounting Considerations - One of the most important considerations when designing and building a Yagi antenna is the method used to attach the elements to a boom. This is true because the boom influences the electrical length of the elements. In this article JH Reisert explain with drawings techniques on mounting yagi antenna elements to a boom

Antennas for 136kHz - A very long and exaustive documentation on building antennas for 136 khz. Includes links to antenna design software for longwave

Home Brew VHF UHF dual band antenna  ^pop - Contructing precedure and tune up of a dual band mobile antenna. This antenna is just a 1/4 wavelength resonator for both UHF and VHF band. It provides no GAIN as compared to other multi-section design.

80 Meter Multiband doublet antenna - 80 meter multiband doublet antenna with open wire feedline for 80-10 meters by N1LO

All HF Band Antennas - F6ITV consideration on HF Antennas, from trap wired anternnas, to center feed antennas.

VHF/UHF Yagi Antenna Design  ^{updated  pop} - Design your vhf yagi antenna online, a JavaScript enhanced web page that implements the design of an antenna in the VHF, UHF by K7MEM

New HF antenna HB9ABX  ^{updated  pop} - A new, revolutionary design allows the construction of small HF antennas, which provide the same efficiency as large antennas. This antenna can be built for all HF bands, from 10 to 80 m.

K8ZT's Ham Radio Resources - K8ZT's Extensive Ham Radio Resources about QRP, Vanity Callsigns, Software, Maps, Kent State, Shack Design, Argonaut, Sommer, Log Analysis

Star Antenna  ^updated - Communication Electronic designs, manufactures and markets antennas for fixed wireless and mobile wireless applications in a wide range of frequency bands.

RACOM - Radio modems - RACOM is a Czech company specialized in design and production of radio modems and other devices for wireless data networks for radio channels from 140 to 900 MHz. RACOM radio data networks are suitable for data transfer in telemetry & SCADA applications, transaction networks, security systems, IP networks and firts of all mobile tracking and fleet management.

CAP Wireless Amplifiers - Design and manufacture application specific microwave and RF amplifiers, upconverters, downconverters and multifunction assemblies.

SoftRock-40 - The SoftRock-40 is a small, low-cost, good-performing "software defined radio" receiver that plugs into a computer USB port and delivers I-Q audio signals to the computer's sound card. It was designed by Tony Parks, KB9YIG and Bill Tracey, KD5TFD as an "SDR sampler project" for hams everywhere to easily try out software defined radio.

Amsat DSP Satellite Transceiver Project - The DSP Satellite Transceiver is a conceptual transceiver designed as a dedicated unit for amateur satellite operators. The initial concept was brought about by the lack of satellite functionality on modern amateur radio transceivers, and the specialized requirements of the ham radio operator who utilizes OSCAR amateur satellites.

Space Weather Education - Special space weather course designed to teach individuals without any background how to predict space weather

Automatic Identification Systems (AIS) - Automatic identification systems (AISs) are designed to be capable of providing information about the ship to other ships and to coastal authorities automatically.

APRS-Beacon - The purpose of the APRS-Beacon is to provide simple APRS-compatible position beacons for up to three Objects. It is designed to 'stand alone' and does not monitor other traffic on the frequency. It can use a single-port TNC (in 'native' mode), a single- or dual-port TNC in Kiss mode or the AGW Packet Engine in order to transmit on up to four radio ports.(When running with AGWPE, APRS-Beacon will also work with Windows 2000)

HamCalc v1.3  ^pop - By G4VWL, HamCalc is collection of calculators for radio amateurs: Antenna ERP calculations. Attenuators. Audio Filter design.Coil Winding. Decibels. Great Circles map and calculator HF Filters HF Traps Metric conversions OP Amps QRA Locator to Latitude/Longitude (and back) Radio Horizon calculator Resonance Satellite orbit calculator Timer calculations (555 timer)Zener Diode calculations

SmartSmith - A smarter version of the Smith Chart program. It allows you to dynamically generate impedance point plots as you configure each design element of an impedance matching network. Has an extensive Help file with a Wizard that tells you what steps to take in designing a matching network for a given load impedance. Complete Windows installation kit by w9dmk

Baudline signal analyzer - A Linux based FFT spectrum analyzer designed for time-frequency browsing and scientific data visualization. Oscilloscope waveform, statistical histogram, accumulated spectral trace,Weak Signal reception, continuos data logging, FFT Analyzer and specialized measurement windows.

Shortwave Log (SWLog) - Shortwave Log, SWLog is a comprehensive logging and radio control program. While designed for shortwave and mediumwave listening, the program is quite adept when listening to longwave, utility, or amateur radio. Support Icom Drake TenTec Yaesu JRC and lowe receivers.

QRM and noise reduction Priority listing - You will find on these pages my experiences and results on antennas and local/non-local QRM/noise reduction. Using a broadband vertical active magnetic loop and a home made / designed broadband amplifier. Two vertical magnetic Alford loops are used in an array. Analog and Digital Signal Processing and a dual phase coherent Software Defined Radio (SDR) are used. By PA0SIM

A 80/40m Direct Conversion HF Receiver with DDS VFO - Juha (OH2NLT) and Matti (OH7SV) have designed JUMA-RX1, an award winning 80/40m direct conversion HF receiver with highly accurate direct digital synthesis VFO. The receiver is very compact, because it constructed using surface mount components. No coils need to be wound to construct this receiver!