rf spectrum

Balun and Transformer Core Selection - Occasionally errors are made regarding core selection. This especially includes baluns, where on occasion some very strange ideas surface.

Transmitting Baluns - One of the most popular Ham-lore rumors is a balun's performance can be tested or evaluated by grabbing the coax and watching for an SWR change. This is probably one of the worse test-rumors circulating

RF in shack with vertical and longwire antennas - Why a vertical antenna or longwire antenna might require a balun

W1CG Low Power Balun Kit - Contruction manual to build a 4:1 balun, it has good performance from 160 through 10 meters.

Detuning Towers - The goal of detuning is not to avoid resonance, but rather to minimize re-radiation and/or current in the interfering structure.

A 16 Turn S-Band Helix - This design represents the smallest practical antenna for Oscar-13 mode-S. Perfect beacon reception at all times is possible, and acceptable SSB even at 43,000 km range.

13 cm Helix Antenna  ^pop - Here is the design of a 2.4 GHz antenna that is ideal for amateur satellite communications. This antenna is easy to assemble because the design itself tolerates inaccuracies in the construction without really affecting performance.

A Horn Antenna for 2.4 GHz. - This Antenna is not really practical for AO-40 reception, but horn antennas have a number of qualities useful in microwave antenna testing and noise figure measurements.

Portable HF antennas - Excel sheet containing technical comparisons of commercial HF portable antennas compiled by ON4SKY. Includes pictures, manufacturer, db gain, band coverage, F/B ratio, price, weight and dimensions.

A Modern Thermocouple Ammeter - Thermocouple ammeters are very rare these days, but the job they were perfect for - measuring antenna currents - is still a modern requirement especially in respect to groundplane currents. By David A. Reid PA3HBB G0BZF

Radiation and fields - Electric Fields, magnetic fields, electromagnetic fields, losses, fresnel zone, nearfield and farfield

DirectionalBiQuad - Seattle Wireless - A biquad is a fairly powerful antenna which is relatively easy to construct, with impressive performance for their size. A link greater than 5 miles can be made with a pair of these as a stand-alone antenna and a Prism2 100mW card, provided you keep coax short, and your line-of-sight is clear.

ARIDX by UA1AAF - At the moment the most used program is UA1AAF. It is an excellent program written by Boris, UA1AAF, to handle ARI International DX Contest. It can simulate K1EA or N6TR workings; it will be possible to connect the RTX to the computer using a standard interface in such a way as to transmit directly in CW from the keyboard; most of the controls are like K1EA's CT and N6TR's TR ; on line help provides almost all the information necessary for using the program. Is possible to insert QSO after the contest. An appropriate utility in included for conversion in ADIF format. The program is very small and therefore works without any problems on any IBM compatible computer with DOS 3.3 and over or Windows 95/98.

RFAC Solutions - RF Connectors Cable Assembly Attenuators Filters High Power VHF Amplifiers, Adapters MMCX MCX SMA SMB SMC BNC TNC N from RFAC Solutions

EZ Hang - The perfect tool when you want to put up a wire antenna easily, quickly and safely! EZ HANG can be used to "shoot" a line over a tree or other object over 100 feet high

Electronika International Inc - Electronika International Inc, Cleveland, OHIO manufacturers wide range of Coaxial Cable Assembly, Coaxial Connectors & Adapters, Power Dividers, Attenuators, Coaxial Switches, Amplifiers, Fiber Optic cords, Bias TEE, Isolator & Circulator and other products

Canada, radio spectrum allocations - Graphical maps of radio spectrum and frequency allocations in canada

F5VLB amateur radio astronomy station Priority listing - F5VLB and EA4EOZ have designed a small but powerful system using satfinder and standard LNB to make radioastronomy. A step by step descritpion for the novice about radioastronomy, VLB and listening to echo of meteorite.

DRF Technologies - Interfacing and Control Projects for the Hobbyist, Ethernet I/O Board, VA3TO Echolink Interface, Programmable Beacon Keyer Project.

ALA Amplifiers - Canadian dealer for many RF Amplifier brands

FFT Explorer - A free (GPL) Linux (Xwindows GUI-based) utility that performs spectral analysis on real-time data from a sound card or other source, and can analyze the spectra of various sound file types. It can also accept data from many kinds of applications in plain-text form by way of the "named pipe" feature of Linux

RFI From Computer Networks - Is your router shutting you down ?

Automotive RFI elimination - ARRL pdf file on how remove car noise from your radio. Modern vehicles are RF noisy environments. Come learn how to identify and silence yor mobile noise sources, by WA6PDP

ARRLWeb: Solving Ignition Noise RFI - Solving Ignition Noise RFI article. Help on removing noise interfences caused by ignition

Alternators & Batteries - Influence of batteries on RFI and noise generation by k0bg