rf signal generator

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 - 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

About digital modes - The digital modes provide a wonderful opportunity for those of us who would like to work on the HF bands but find CW too difficult and SSB phone prohibitive because of interference problems. The digital modes are easy to set up and get operating, require low power and a narrow band.

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.

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

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.

Jason - Jason is a weaksignal communication program, especially tailored for LF work.

WD6CNF DSP Filter - Audio Digital Filter, two bandpass filters, three notch filters, two noise filters graphical setting of filter center frequency and bandwidth Drag vertical lines on top of signal, Microphone input, speaker output Mono, 5 kHz bandwidth

Phase 3D (AO-40) Decoder - This program demodulates the telemetry data signal transmitted by the AO-40 satellite (aka Phase III-D) using the PC sound card

Konfabulator - DX Cluster Priority listing - Freeware windows XP and MacOSX konfabulator widget dedicated to Amateur radio operators, is an easy interface to DX-Summit the ham-radio DX Cluster. DX cluster spots represents live ham radio communication connections, and are an invaluable resource for amateur radio operators. Users can choose Bands or operating modes like digital emissions, QRP IOTA and more. Spots are refreshed automatically and refresh rate can be set by users, with a minimum of 100 seconds.

LocCalc - Distance and directions calculation program using both Spheric, the perfect round earth model, and Vincenty's inverse ellipsoid algorithm, the WGS 84 earth model.

QuikPSK - 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.

Packet Terminal Interface - Simple Windows based TNC interface program Designed for ARES operation, simple operator interface to connect and perform communication functions, control operator programs screens before operations Both receive and transmit screens Simple Windows based TNC interface program Designed for ARES operation Simple operator interface to connect and perform communication functions Control operator programs screens before operations Both receive and transmit screens

FT-100D for PalmOs - Palm interface for the FT100D by Andre, HB9FBD

eQSLMaster - eQSLMaster is a HAM radio program, that allow to perform various functions using the Electronic QSL Card Centre (eQSL.cc). With eQSLMaster users of the eQSL.cc system have the ability to upload an entire ADIF format log file (or single QSO) and have it deposited into eQSL central database using LogServices.

TCube - TCUBE is a combination of a Spectrum Analyzer and a Two Tone Generator, with optional quadrature outputs. It can be used for measuring the intermodulation behavior of an audio circuit, and as a general purpose tool

SpectraScope - SpectraScope is a simple Windows interface program allowing your computer to view up to two audio waveforms in either the time or frequency domain. The program is a Windows soft panel operating as a dual channel oscilloscope and spectrum analyzer. The useful frequency of operation is 20 to 10,000 Hz in the time domain and 20 to 20,000 Hz in the frequency domain. The program uses the computer sound card to capture the audio input.

HamView - A freeware program to dig out weak signals buried in noise, functionally similar to the excellent FFTDSP of AF9Y, but with the added bonus of real time audio filtering of the incoming signals. Just point and click with the mouse, and the selected signal will stand out from the QRM and noise.

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.

QRM and noise reduction Priority listing - You will find on these pages my experiences and results on antennas and local/non-local QRM/noise reduction. Using a broadband vertical active magnetic loop and a home made / designed broadband amplifier. Two vertical magnetic Alford loops are used in an array. Analog and Digital Signal Processing and a dual phase coherent Software Defined Radio (SDR) are used. By PA0SIM

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!

Kenwood to pc serial ports - Simple, low cost interface between Kenwood serial ports and contest logging programs by Bob Wolbert, K6XX