- 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.
Feeding the Beast
- Transferring Radio Frequency Energy from Your Transmitter to Your Antenna by Don Keith N4KC
NCDXF/IARU Beacon Project
- The NCDXF, in cooperation with the IARU, constructed and operates a worldwide network of high-frequency radio beacons on 14.100, 18.110, 21.150, 24.930, and 28.200 megaHertz. These beacons help both amateur and commercial high-frequency radio users assess the current condition of the ionosphere
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.
Frequency Calibration for Weak Signal Work
- Accurate calibration of your receiver and sound card is necessary for good results with the weak signal modes in use at LF. Modern receivers with master oscillators that are synthesized to provide all conversion frequencies greatly simplify the process. This article describes a method of making the necessary measurements and adjustments to an ICOM R75 receiver and a sound card, using the ARGO software
Really Low Frequency Operating
- The world below 500 kHz (The wavelength is 1500 meters or just about a mile) has a number of interesting listening and communications opportunities with possibly more to come.
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.
- CB Radios, Scanners, Radar Detectors, Two Way Radios/GPS store. Products you can trust Cobra, Uniden, Garmin, Rocky Mountain, Whistler and more. We are your specialty store for your mobile communication needs. Based in Tampa Florida.
- 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)
Baudline signal analyzer
- A Linux based FFT spectrum analyzer designed for time-frequency browsing and scientific data visualization. Oscilloscope waveform, statistical histogram, accumulated spectral trace,Weak Signal reception, continuos data logging, FFT Analyzer and specialized measurement windows.
- Supports both PSK31 and PSK63, sends and receives color thumbnail portraits by PSK63, displays 24 PSK63 channels simultaneously, and features semi-automatic mode selection between PSK63 and PSK31. Merely left-click on a PSK63 signal to copy, or right-click on a PSK31 signal to copy.
Safety: RF awarness guidelines
- Although Amateur Radio is basically a safe activity, in recent years there has been considerable discussion and concern about
the possible hazards of electromagnetic radiation (EMR), including both RF energy and power frequency (50-60 Hz) electromagnetic fields. This section summarizes what is now known and offers safety precautions based on the research to date.
Wavefront CompactPCI (CPCI) RF converter
- The Wavefront CompactPCI (CPCI) RF converter provides a complete half-duplex radio front-end in an industry-standard 6U format. The architecture consists of dedicated receive and
transmit channels that share a common RF interface.