audio signal generator

K5DZE Becon - The K5DZE/B 10 Meter Beacon currently operates on 28.228 MHz 24/7 transmitting a CW signal at 18 WPM as an aid to check 28 MHz propagation Northern Kentucky

WebSDR for VLF and 70 cm band - Operated by Wouter Weggelaar PA3WEG in Delft Holland, it allow reception of VLF and 70cm band to receive satellite signals

CoaxMan - The Coaxman by Clear Signal Products, Inc. features a complete Wireman line of coaxial cable and antenna wire. Antenna wire, baluns, coax connectors, insulators, ladder line, magnet wire, rope.

Farallon Electronics - PACTOR mode radio modems and accessories, performance sailing electronics and innovative hard to find parts. Audio cables, packet cables, usb to serial converters

Elenco Electronics - Test equipment maker, digital oscilloscopes, generators and counters, multimeters, logic probes testers and more

IWATSU - Test instruments corporation produces digital multimeters, Oscilloscopes, signal generators, universal counters

Leader - Waveform monitor, rasterizer, video and rf generators

USBee - PC and USB Oscilloscope, Logic Analyzer, Signal Generator and Protocol Decoder and Analyzer

Gage Applied Technologies - Gage applied technologies designs and manufactures high-speed data acquisition systems, high-speed digitizers in pci / cpci / pxi or pc oscilloscopes, providing utmost measurement fidelity for high frequency signals.

BK Precision - Power supplies, electrical testers, battery analyzers, cable tester, rf generators, spectrum analyzers, Digital/Analog Oscilloscopes, Multimeters , attenuators, frequency counter

A Guide to Test Equipment - That just about sums up many peoples’ attitude towards test equipment. Multimeter, SWR/Power Meter, Dip Oscillator, RF Signal Generator, Cathode Ray Oscilloscope

W1TAG WD2XES WE2XGR/3 - Experimental Stations Run by W1TAG WD2XES has been used to study LF antenna design, propagation and communication modes. Signals from WD2XES have been copied as far away as Russia.

Operating Meteorscatter - Meteorscatter (MS) describes a propagation mode whereby the signal is reflected from rather small ionised patches in the E-region of the ionosphere.

Grabber Compendium by I2NDT  ^updated - Screenshots of live QRSS signals from all over the world

Lehman scientific - New unused surplus and used electronic test and laboratory equipment including spectrum analyzers, signal generators and oscilloscope

Scientific Surplus - Buy, sell and trade electronic and scientific instruments. Oscilloscopes, microscopes, signal generators, RF equipment, short & long wave radios, meters and wattmeters, detectors (radiation, metal), spectrum & network analysers military equipment

Naptech - Naptech buys and sells quality test equipment from hp, tektronix, including spectrum analyzers & peripherals, oscilloscope, frequency counters timers, signal generators, multimeters & voltmeters, RF & power meters, microwave amplifiers

PDW Paging Decoder - This free windows software allows you to decode digital signals like FLEX, POCSAG, ERMES, MOBITEX and ACARS.

Filtroid - Filtroid is an extremely easy-to-use program for synthesizing microwave filters. It can be used to design practically all filter types from audio to microwave frequencies as well as amplitude and delay equalizers and attenuators.

RSCW - RSCW is a Linux/Unix program for decoding morse signals using the computer's sound card. It has been written/optimized for digging weak signals out of the noise.

PropNerPSK - PropNetPSK is a PSK (Phase Shift Keying) program capable of receiving multiple signals (2 - 16) at one time for the exclusive use to decode a properly formatted PropNetPSK beacon signal. If you are looking for a Keyboard to Keyboard type of program, this will not fit your bill.

Radio Clock - Radio Clock listens to radio time signals from your radio and corrects the time on your PC clock

A simplified video control box - When one starts in amateur television, one begins with a small simple transmitter and a small camera. But very quickly, one needs to transmit audio signals with the pictures, then comes a second camera

CW keyer - The PIC-MORSE is an electronic iambic keyer, integrating a generator of Morse code and a sidetone. It is built with a microcontroller PIC16C711. In French

Microwave spectrum analyzer - A practical approach to microwave signal analysis for the home experimenter