yagi design

Cubic Quad  ^pop - The cubic quad is a very popular way to get reasonably high gain and excellent front to back ratios as well as low angles of radiation for without going to extreme heights. Includes design for 2 6 10 12 15 meter bands

A portable 2-element VHF yagi  ^pop - Build a portable VHF yagi antenna for 2 meters. All you need is two rabbit ear antennas from Radio Shack, two CATV baluns, four feet of 3/4 CPVC pipe with one tee.

Portable Yagi for 144MHz - Simple 7 element Yagi is ideal for portable operation.

Transmission Lines - Whenever you choose a coax feedline, the frequency of operation is a very important consideration. Over the operating bandwidth of the coax the VSWR is low, typically 1.2:1 or better. Insertion loss is also an important parameter. It is usually specified in dB/foot and is a linear relationship.

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

Pfeiffer Quads - The Pfeiffer Quad was described in QST and has the desirable feature that it is smaller than a standard cubic quad but does not compromise performance very much. The Pfeiffer design is rather difficult to construct because of the complicated linear loading networks required.

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.

DF3CB BV QSL Management and printing - DF3CB site, contesting, and software BV is a professional freeware software for the QSL Management and Label/QSL Printing under Windows developed and distributed by Bernd Koch, DF3CB, since 1989. It is mainly designed for the contester and QSL manager with high QSL quantities but useful for all other QSL'ing purposes as well. Includes logging features

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.

Telewave - Telewave's innovative engineering produces the industry's toughest antenna systems. Yagi, Fiberglass Collinear, and Dipole models are available from 66-2500 MHz. Wattmeters, test equipment,rf power meters, duplexers, filters and cavities, transmitters combiners

The ElectroMagnetic spectrum - Excellent poster representing the electromagnetic spectrum from 31.2 mHz to 6.52 EHz, PDF file poster designed by Anthony Tekatch

Fax480 - FAX480 was developed to provide for relatively high resolution image transmission on HF, VHF, and UHF amateur radio bands. FAX480 was designed to bridge the gap between conventional slow scan television (SSTV) and conventional facsimile techniques.

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

QSL Canada - Very high quality QSLs with prices that fit any budget. Large selection of cards style, free design.

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  ^{updated  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

Packet Terminal Interface - Simple Windows based TNC interface program Designed for ARES operation, simple operator interface to connect and perform communication functions, control operator programs screens before operations Both receive and transmit screens Simple Windows based TNC interface program Designed for ARES operation Simple operator interface to connect and perform communication functions Control operator programs screens before operations Both receive and transmit screens

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.

Kenwood TS-950S RF gain mod - The Kenwood TS-950S and TS-950SD HF transceivers are fine radios. However, many, if not all, of them were produced with a design flaw which allows the RG GAIN control to cease function in the presence of a strong signal IF the AGC has been turned OFF

A 80/40m DDS controlled QRP CW transmitter - JUMA-TX1 is a 5W CW transmitter for the 80/40m bands. Juha (OH2NLT) and Matti (OH7SV) have had high quality CW keying and a compact size as design goals for this project. No coils need to be wound to construct this transmitter!

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!