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  • Digital Communications

    A great number of exciting new digital operating modes have developed, largely because of the availability of personal computers, soundcards, and advanced software. But amateur digital communication began in earnest in the late 1940's (if you don't count Morse as a digital mode!) when hams worked out techniques of connecting mechanical Teletype keyboard/printers to amateur gear using FSK and AFSK modulation. WSJT has become a very popular tool for digital communications. FSK441 mode is in use for meteor scatter contacts and JT65 is popular for terrestrial communications.

  • EME Moonbounce

    Amateur radio (ham) operators utilize EME for two-way communications. EME presents significant challenges to amateur operators interested in working weak signal communications. Currently, EME provides the longest communications path any two stations on Earth can utilize for bi-directional communications. Amateur operations use VHF, UHF and microwave frequencies. All amateur frequency bands from 50 MHz to 47 GHz have been used successfully, but most EME communications are on the 2 meter, 70-centimeter, or 23-centimeter bands. Common modulation modes utilized by amateurs are continuous wave with Morse Code, digital (JT65) and when the link budgets allow, voice..

  • Aurora and Solar Weather

    The interaction between Earth's magnetic field and Solar particles is a complex and mysterious field of science. The storm events involve high electric currents in the ionosphere and vast amounts electric power affecting to great many things. One of the ways to observe what is happening up there, is to detect the effects of these phenomena to non ionizing long wave electromagnetic radiation - radio waves.

  • VHF Contesting and Rover Operations

    Hams have been putting stations in their cars since the Twenties (1920's that is). Today, there is great satisfaction in facing the challenge of installing a transceiver in our small cars and pick-ups, using somewhat inefficient antennas, and still being able to make contacts with hams thousands of miles away while "tooling" down the highway.

  • Annual Technical Conference

    Every year since 1968, during the last weekend in July, the Central States VHF Society hosts an annual technical conference. There are two days of technical presentations, antenna range gain measurements, noise figure measurements, a flea market, and often times a vendor area. It's a great time to learn about weak signal VHF communications and an excellent place to network and catch up with old friends.

**-Central States VHF Society

Exploring the World Above 50MHz since 1965

Noise Figure Results

Noise Figure Measurements

1995 - 2010

The Central States VHF Society has conducted Noise Figure Measurements since the late 1970's. In the early days results were tabulated and sent out with the following years conference announcement. In more recent years the results have been handed out at the end of the conference. The results are usually also published in the following year's proceedings. The published results can be used to make comparisons between commercial and homebrew preamps, between different homebrew designs, and between different devices from different manufacturers. In recent years the equipment used to measure noise figure has been the HP8970 Noise Figure Meter and HP346A Noise Source. Measurement accuracy of the system according to HP is +/- 0.2 db! The Noise Figure Measurements have been for many years conducted under the diligent guidance of Al WB5LUA and Tommy WD5AGO. Al and Tommy have provided equipment and the expertise that has made the results published by CSVHFS a recognized standard. In recent years, others have stepped up as well, like Tony WA8RJF and Pete K9PW, and so on. The Society sincerely appreciates their hard work and dedication.


1995 Noise Figure Results

1996 Noise Figure Results

1997 Noise Figure Results

1998 Noise Figure Results

1999 Noise Figure Results

2000 Noise Figure Results

2001 Noise Figure Results

2002 Noise Figure Results

2003 Noise Figure Results

2004 Noise Figure Results

2005 Noise Figure Results

2006 Noise Figure Results

2007 Noise Figure Results

2008 Noise Figure Results

2009 Noise Figure Results

2010 Noise Figure Results