cobra 19

The 2-Element-HB9CV-Beam  ^updated - The HB9CV-Beam is a 2-Element-Yagi with two driven elements and was introduced by Rudolf Baumgartner, HB9CV in the 1950ies. The Beam is a coax-feeded version of the ZL-Special Construction by DK7ZB for 2m, 6m and 10m

80/75 Meter 4-Square Array - This array has been in use since 1989. The SWR from 3.5 to 3.9 is below 1.5:1. The F/R of the array is 20dB average and with some signals even better.

The Impact of Current Distribution on Array Patterns - Technical Correspondence, QST, July 1990 - Why even "perfect" phased array element currents don't produce perfect patterns.

The Broadband Double-Bazooka - The Broadband Double-Bazooka Antenna — How Broad Is It? 18-1. (Adapted from Technical Correspon- dence, QST, September 1976) The increasing interest in using the coaxial dipole.

The DK7ZB-Match for Yagis - Simple, easy to built match developed in 1995 for Yagis with resistitive loads of 12.5, 18 and 28 Ohm.

A 5 band log periodic dipole array - Modified version of the Telerana antenna which was orginially featured in the July 1979 issue of QST. The array is suspended within a framework made of fiberglass poles emanating from a central hub with the ends tied together with light weight rope around the perimeter. 10-15-20-30-40 meter band coverage

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.

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

A *balanced* balanced antenna tuner  ^pop - The published version of this article appeared in the February 1990 issue of QST Magazine

Granta Contest Group - HF amplifier - The Granta Contest Group was founded in 1997 by Mark G4AXX, Colin G4CWH, Simon G4EAG, Andy G4KNO. The Group gets it's name from the River Granta (or Cam), which passes through Cambridgeshire and Essex. Using is a 160-10m "desktop kilowatt" linear amplifier using an Eimac 4CX1000A tetrode

KD4MZM Beacon system - The kd4mzm ham radio beacon system running a Cobra 148 GTL 40 channel AM/SSB unit modified to the 10 meter band

CQWW 1998 from PA3HBB - Reportage of the CQWW CW contest in 1998, with full history of the event and photos of equipment used.

VK3DK dx-pedition to Gabo Island - Dxpedition to gabo island, australia, sept 2001 OC-196, ARLHS# aus-078, WLH No: 1031

IOTA maps - QSL and Map gallery of IOTA islands all over the world

VK8NSB's IOTA page - Melville Island OC-173, Croker Island OC-229, IOTA DXpedition 1999

W5BBS Broken Arrow Amateur Radio Club - Founded in 1978 to provide support for local amateur radio operators

Multi-Tech Industries, Inc. - Manufacturing Precision Products Since 1969. Rotary Switches, Strain Reliefs, Ground Fault Units

Micro Computer Concepts - Micro Computer Concepts is a manufacture of radio repeaters, repeater controllers and repeater related accessories. MCC started making repeater controllers in 1988 and has supplied the Amateur Radio community with a varity of products.

How to Work 6 Meter DX by W3EP - December 1998 QST World Above 50MHz copyright ARRL

Radio Scanner Guide - A guide to selecting Radio Scanners; divides both new and used radio scanners into 6 categories, based on their specifications and features - e.g. analog trunking scanners, digital trunking scanners, etc; provides specifications on each model

Adding 160M to HF amplifiers - updated original manuscript, article published in January 1989 QST by Richard L. Measures, AG6K, April 1988

HF QRP Lin Ampl - HF QRP Linear Amplifier with 2x 2SC2166 + 2x 2SC1969 Push Pull Transistors (13.8V)

IK5MEN HF amplifier 10-160m. - Italian page including pictures schematics diagrams of an home made linear amplifier using four EL509 in parallel. Output power is about 700W.

PHEMT (GaAs FET) Preamplifiers - Angle Linear has been producing GaAs FET preamplifiers since 1980

50MHz-Transverter 10m/6m from DK7ZB - This transverter was built in 1994, a discription in three parts (german language) for DOWNLOAD as PDF-files. Circuit, printed-boards and layouts in the files