rf spectrum

Portable Magnetic Loop Antenna Version 2 - A simple multi-band magnetic loop antenna designed for 20, 30 and 40 metres. For its size, the performance of the antenna always astounds me, although it is never going to replace a Yagi

W5GI Mystery Antenna  ^{updated  pop} - W5GI Mystery Antenna is a multi-band wire antenna that performs exceptionally well even though it confounds antenna modeling software. This antenna covers 80 to 6 meters with low feed point impedance and will work with most radios, with or without an antenna tuner. It is approximately 100 feet long, can handle the legal limit, and is easy and inexpensive to build. It�s similar to a G5RV but a much better performer especially on 20 meters.

W7AV 40 Meter Half Square - These antennas offer big gun DX performance on the low bands, yet they are surprisingly simple to build. Try one- you will like it!

20 meters Cage Dipole - Cage Dipole is based on the fact that a wireframe does emulate a tubing of the same diameter, supposed that the wires in the frame are close enough to resemble a solid surface.

G/T Simulations - by VE7BQH - Here you will find information on how antennas behave when stacked G/T is an important figure-of-merit for the antenna's overall receive performance, because it balances forward gain (G) against received thermal noise (T).

German Call Sign search - Callsign lookup form for german calls

SPE Amplifiers - SPE Makers of RF power amplifiers like Expert 1K-FA Expert 2K-FA

RF HAMDESIGN - An engineering oriented organization specializing in the design and manufacture of high performance parabolic antennas, 3dB high power RF couplers, Antenna power splitters, directional RF couplers and more items for RF transmission from HF through Microwave frequencies.

Eliminate QRM from 6 meters band - The circuit described below will substantially reduce or completely eliminate interference from almost any local source whilst leaving the wanted signal relatively unaffected, even though it may be on the same frequencey by TREVOR, G3ZYY

Lan Link for Windows - Lan Link for Windows by G3ZCZ, Internet interface to CXCluster, Controls PK-232, PK-900, PK-88, KAM, KPC-3, MFJ1278, and TNC2, PSK31 via the sound card in the PC, eQSL interface

HL1INF RF Amplifiers - Circuits, pictures and data about toroids, tubes and home made power amplifiers

AG6K Richard L. Measures - Articles and original manuscripts on RF power amplifiers

K0GKD Solid State amplifier - High Power Solid State 600 Watts Output Motorola MRF 150 FETs

N4IP HF and 6 Meters amplifier - A solid state amplifier for HF and 6 meters band by N4IP

11 KW Linear amplifier by I0JX  ^pop - Use 4CX10000D / 8171, RF output power of 11 KW in key-down carrier on all bands. Power was measured with a Bird 4712 wattmeter and a 25 KW slug

Base-Station RF Power-Amplifier Biasing - Power amplifiers used in base stations require biasing for proper RF performance. This article explains the two classes of biasing that are prevalent in the RF industry, analyzes their characteristics, and shows implementations with existing ICs.

The Approx. Perfect Amplifier manuscript - Discussion of some design features that would be present in a perfect, or near-perfect, amplifier.

Vacuum Tube Amps - How the tube converts DC to RF Power

Introduction to amplifier design - These tutorials will teach you in very easy steps how to design A class amplifiers.

13cm RF Amplifier - This amplifier uses two 60w Spectrian amplifier boards with the usual input and output hybrid coupler and combiner.

PA7TA RF Amplifiers - VHF UHF Amplifiers

144/430 Duplexer - Schematics for a VHF UHF duplexer

A diode-switched band-pass filter - High speed silicn diodes work well as RF switches. This article describes how to use diodes for selecting two or more filters ARRL QST article by W1FB

RFI - Intermodulation - Getting squeaks and squawks from your H-T? Are pagers crunching your mobile rig's front end? Here's how intermod happens--and how to fight back!

The Basic Soldering Guide Photo Gallery - These photos illustrate the basic steps in making a perfect solder joint on a p.c.b