alert system

Understanding Standing Wave Ratios SWR - We worry a lot about Standing Wave Ratio (SWR) in amateur radio since SWR is one indication of how well our antenna system is working. Most HF transceivers and antenna tuners have built in SWR meters. SWR is a measure of a transceiver’s output power verses the portion of that power reflected by the antenna system By Ken Larson KJ6RZ

SWR: Maximum allowable VSWR - VSWR (voltage-standing-wave-ratio) represents the degree with which an antenna is "matched" to the system impedance. Most modern antennas do not require any tuning for optimum performance. VSWR is one of the easiest parameters to measure and VSWR meters are becoming very popular antenna installation tools

Setting the SWR of Your Antenna - SWR (standing wave ratio), is a measurement of how efficiently your antenna system will radiate the power available from your radio. In simple terms, your radio would like to radiate all of its power, but can only do so if the other components cooperate

Antenna Polarization notes - Antenna polarization is a very important consideration when choosing and installing an antenna. Most communications systems use either vertical, horizontal or circular polarization. Knowing the difference between polarizations and how to maximize their benefit is very important to the antenna user.

Newark Amateur Radio Association - The mission of this Association is to foster and promote the hobby of Amateur Radio, to provide repeater systems for the Amateur Radio community, to provide public service and emergency communications when needed, to provide education for licensing, and to provide a forum for members to meet and exchange information, share experiences, and socialize with one another.

11metertraffic.com Priority listing - BAnner exchange system offer quality traffic at for your 11 meter site

Hamradio Board.de - German amateur radio portal mainly based on a bboard system, by DO1YAO

Ham Lake, Minnesota IC-PCR1000 - The system consists of a Icom IC-PCR1000 shortwave radio. Coverage is from 10 KHz to 1300 MHz.. Antenna is a Par Electronics EF-SWL in and sloper configuration.

GLA Systems - Texas BugCatcher antenna manufacturers. Mobile antenna for hf bands. The serious HF Mobile Antenna by Henry Allen, K5BUG

KVK Antenna Systems - The manufacturer of the NuBeam, Vipole, and the multi-band Quad-Folded-Dipole (or QFD for short) antenna. Also have a unique multiband vertical which can combine operation on multiple HF frequencies as well as provide high gain on 50, 144 and 438MHz in a single antenna.

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.

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

Antenna Noise and Signal Cancelling at LF - The fact that the phasing between a wanted signal and an unwanted signal can be different on different antennas is put to advantage. With this condition, the unwanted signal can be cancelled out by controlling amplitude and phase. The heart of the system is some form of phase control circuitry.

W2LJ's QRP Amateur Radio - Dedicated to QRP, Morse Code and operating in the great outdoors, this pages contains a description of a CW QRP portable set, also some stuff on the Buddipole and PAC-12 antenna systems.

Transmitter hunting, in San Francisco Priority listing - Amateur radio direction finding, transmitter hunting. triangulating a radio signal direction and plotting its bearing on a map. hunters use doppler systems for tracking hidden transmitters

HF Antennas for restricted space - Arrl document about invisible antennas and indoor systems. It is important to consider that few compromise antennas are capable of delivering the performance one can expect from the full-size variety. But the patient and skillful operator can often do as well as some fellows who are equipped with high power and full-size antennas. The "cliff-dweller" may not be able to "bore a hole" in the band as often, and as easily, but DX can be worked successfully when band conditions are suitable.

SB-220 / 200 Amplifier with Solid-State Transceivers - Using Solid-State Transceivers With Older Tube Amplifiers, some Hines and Kinks on the Heath SB-220/200 that can be useful in your application

The Radio Reference - RadioReference.com, scanner frequency and radio communications reference source, with complete conventional frequency assignments, trunked radio system information, frequencies, and talkgroups, FCC License assignments and maps, 10-Code Lists, agency maps, files, downloads, links, and detailed agency information for most public safety, military, and local government activities.

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.

Automatic Identification System Overview - USCG Navigation Center - What is the Automatic Identification System (AIS)?

Win APRS - Automatic Position Reporting System windows program, allow monitoring of real time geographical information such as the position of vehicles, the status of weather, radio direction finding and more.

Shipplotter - ShipPlotter displays complete information about ships that are within VHF range of your position using the Universal Automatic Identification System (AIS).

ComTekk Tone Generator - ComTekk Software Tone generator for 2-way radio signaling. Use sound card to generate CTCSS, DTMF, tone remote, ANI and more. Synthesizer for simulation and testing of 2-way radio systems, repeaters, remote control, ANI, Paging and more

BCD396T Manager Priority listing - Uniden BCD396T control and programming software written in tcl/tk for all linux/*nix systems. Should run on any system that has tcl/tk.

Antenna elevator system for amateur satellites  ^pop - Smart homebrew antenna-ELEVATOR system with linear actuator. The actuator is a cheap and heavy tool with high enough torque, ideal for elevation systems, but in practice it needs quite an effort in order to operate correctly in your homebrew antenna system. This page inform you of the actuator's secrets.