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
Copper J-Pole Antennas
- Conejo Valley Amateur Radio Club, article edited by Rory Eikland, KG6HCU and Ken Larson, KJ6RZ, they have had excellent experience building and using J-Pole antennas, and share their experience on planning VHF and UHF Jpole antennas.
Add 60 meters to butternut vertical antenna
- The Butternut vertical is a great antenna in that it covers all HF bands from 160- though
10-meters (or 160-30 meters for the HF-2V) except 60-meters. This article describes
three methods to add 60 meters to your Butternut vertical without losing any other bands.
PJ9JT Contesting QTH
- SignalPoint, Caribbean Contesting Consortium. Curacao. CCC's contesting QTH is the former home of PJ9JT, John Thompson, W1BIH. This historic site has been the home of many contest wins since 1971.
- Formed in 1987, serve the west part of Cambridgeshire that straddles the valley of the river Great Ouse and was the old county of Huntingdonshire. This includes the market towns of Huntingdon, St Neots, St Ives and Ramsey.
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.
- The SoftRock-40 is a small, low-cost, good-performing "software defined radio" receiver that plugs into a computer USB port and delivers I-Q audio signals to the computer's sound card. It was designed by Tony Parks, KB9YIG and Bill Tracey, KD5TFD as an "SDR sampler project" for hams everywhere to easily try out software defined radio.
- In the VLF portion of the spectrum it is easy to listen to the emissions created by the Earth itself. These emissions are generated by many different mechanisms and are often beautiful to listen to. Coverage on LF and MF frequencies
Thunt.org : transmitter hunting
- Amateur radio direction finding, transmitter hunting web site from San Francisco. Triangulating a radio signal direction and plotting its bearing on a map. Hunters use doppler systems for tracking hidden transmitters anywhere in the san francisco bay area, fremont california
Direction finding, HVDFA
- The HVDFA is dedicated to fostering skills in the area of Radio Direction Finding as an interesting facet of Amateur Radio, both as a sport and for public service, in the multi-state region surrounding the Hudson River Valley of New York.
Smith Chart Software
- SimSmith is a highly interactive, real time Smith chart graphing program. Circuits are constructed using drag-n-drop. Load files can be imported from the EZNEC and CocoaNEC antenna simulation software and from the AIM4170 and miniVNApro antenna analyzers. Circuits and load files can be of any size.
Key Features: SimSmith is one of the few Smith chart packages which models transmission line losses. SimSmith also allows the description of circuit elements using algebraic equations. SimSmith has only one screen and allows the screen to be resized to increase workspace or readability.
Assessing unknown Ferrite Toroids
- Ok so you have had a good day at the Rally and you have come back with a carrier bag full of ferrite toroids that "just might be useful for something". How do you find out what they are? Very few seem to be stamped with any indication of their properties, and some are 'painted' garish colours which presumably means something.