spectrum analizers?

Longwave Non-Directional Beacons - Beacons operating in the longwave radio spectrum, generally between 200 and 450 kHz

Optoelectronics - DTMF, RF, decoders receivers and accessories icluding computer interface boards, frequency counters, tone decoders, spectrum sweeper and nearfield receivers

Antenna Products - Antennas cover the RF spectrum from kilohertz to gigahertz and support countless mission critical military, air-sea navigation, ILS and voice-data communications applications.

ScanStar - Radio spectrum monitoring and analysis tools for industry and government

US Frequency Allocation Chart - Colorfull radio frequency spectrum allocations in the US, in PDF Format

The Radio Spectrum  ^pop - Radio frequency allocations

US Spectrum Requirements - Amateur and amateur-satellite services, current uses of the amateur service

Caltech Submillimeter Observatory (CSO) - A 10.4-meter diameter, submillimeter spectrum telescope. Situated at the top of Mauna Kea, Big island, Hawaii.

FCRAO - A 15-meter diameter, submillimeter spectrum telescope. Situated near the summit of Mauna Kea, Big island, Hawaii.

Radio Propagation - Spread Spectrum Scene. Radio Propagation notes, with downloadable files.

VHF UHF Microwave Radio Propagation - Notes on radio propagation in that part of the spectrum (upper VHF to microwave) used by experimenters for high-speed digital transmission

North Ireland scanner info - Frequency spectrum, civilian and military frequencies

All Spectrum Electronics - Hobby kits and electronics, semiconductors, components, batteries, ham radio gear and more

Muir Communications Ltd - Victoria BC. - Amateur Radio and 2-way commercial Radio Dealer. Sales and service for ICOM Radio Products. CB Radios, antennas and installations. Spread Spectrum Radio modems.

Isis Electronics (Cheltenham) Ltd - UK Sales of used RACAL, Watkins-Johnson, Icom, Microwave. Large Qty Racal 1792 in Stock. Spectrum Analysers, UHF,VHF Generators, Network Analysers, Bus Switches.

BeaconSee - BeaconSee shows you, in real time, worldwide HF band openings on your PC. Analyses the audio signals from your radio, which is tuned to the NCDXF IARU HF beacon network and shows you the signal strength received from each of the 18 beacon transmitters as a plot of frequency spectrum against time.

DigiPan  ^pop - DigiPan provides a panoramic display of the frequency spectrum in the form of an active dial scale extending the full width of the computer screen. DigiPan is the result of a joint effort between myself and Nick Fedoseev, UT2UZ, the author of MIXW32, and is intended to make PSK31 operation easier and more enjoyable for everyone.

RX-PSK31 - Easy to use Audio Spectrum and PSK31 decoding program specially designed for SWL's who don't need TX or for anyone who just like to monitor PSK31 or analyse signals. Adjustable DSP and Spectrum settings for audio and frequency spectrum to set for best decoding of PSK31.

Scan*Star - Radio monitoring and analysis tools. Scanning, searching, spectrum analysis and traffic analysis. Amateur, Industry & Government,

Spectrogram  ^pop - Shareware dual channel audio spectrum analyzer for Windows 2000/XP which can provide either a scrolling time-frequency display or a spectrum analyzer scope display in real time for any sound source connected to your sound card. Can be used for MTHELL, QRSS and DFCW by R S Horne

MDS Spectrum Analyzer - Software for radiomonitoring, radio spectrum analysis.

Zelscope  ^pop - Zelscope is a Windows software that converts your PC into a dual-trace storage oscilloscope and spectrum analyzer. It uses your computer's sound card as analog-to-digital converter, presenting a real-time waveform or spectrum of the signal - which can be music, speech, or output from an electronic circuit.

Spectra - Accurate spectrum analyzer in the range 0 - 2500 Hz, makes an accurate FFT analysis of an audio signal coming from the soundcard

GSpec - Spectrum Analyser for Win9x/2000 and NT, that will display audio input to your sound card in the Frequency and Time domains

Spectrum Analyzer Project - This is a tracking page for a tv tuners based homebrew spectrum analyzer project.