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
- 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
ESA Portal - Calling all radio amateursPriority listing
- Radio amateurs worldwide are being asked to help collect data from the student-built SSETI Express satellite, due to be placed in orbit on 27 September. To encourage them, ESA’s Education department has organised two competitions and is supplying free downloadable software.
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.
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.
DF9CY Project Auriga
- PA is a JAVA software package containing several programs, SW/VHF/UHF Logbook (imports format from RADIOMAN, VMT), Log conversion to HTML format,
Import and export functions for RADIOMAN, CT RES files, BV QSL Labels, CSV etc.
Internet DX-Cluster support, Keeps track of your worked Callsigns, Checks your worked Grid Squares per band, Databases for worked Grids and Callsigns
Uses K1EA CQWW.CTY country file,
Easy command line version for terminal operation
Moontracking as clock, Pathloss calculation
Amateur Radio RF Safety Calculator
- University of Texas Amateur Radio Club RF-Calculator. This is a main beam power density estimation program intended for use as part of a routine evaluation of RF safety compliance with FCC regulations
RF Coaxial Connectors
- RF coax(ial) connectors are a vital link in the radio spectrum. Coax connectors are often used to interface two units such as the antenna to a transmission line, a receiver or a transmitter. The proper choice of a coax connector will facilitate this interface.
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.
A 80/40m Direct Conversion HF Receiver with DDS VFO
- Juha (OH2NLT) and Matti (OH7SV) have designed JUMA-RX1, an award winning 80/40m direct conversion HF receiver with highly accurate direct digital synthesis VFO. The receiver is very compact, because it constructed using surface mount components. No coils need to be wound to construct this receiver!