low pass audio filter

The TTFD-2 antenna - The lowest-cost approach for home brewing broadband, general-purpose antenna for shortwaves

Loop Antenna for 6m  ^pop - Indoor loop antenna for six meters band, project by Colen Harlow, G8BTK

CB Quad antenna  ^pop - A low-cost and easy to build Quad antenna tuned for CB band on 27 Mhz.

QNEWS Ham Radio News - Daily updates to the weekly QNEWS Ham Radio News service in text realaudio and RF

RSGB HF Data Band Plans - The following frequencies are assigned to datacommunications in the HF bands within the UK By RSGB data communications committee information.

XE1XZQ Diego - Weekly bolletins of XE1RCS in RealAudio

XE1YJS Joaquin - Ham radio, Mir contact samples in Real audio, packet and some links

EA3QP Eugeni - Ham Radio Web - Devoted to: Contest, QSL info and SSB Audio.

US Police Scanner  ^{updated  pop} - Live, 24-hour audio broadcasts of police scanners in major cities around the United States.

K-Com - comprehensive line of products for rejection of Radio Frequency Interference (RFI) to telephone equipment.

W2IHY Audio Products - Band audio equalizer and noise gate compatiable with ICOM, KENWOOD, YAESU and other radios

Getting started on EME - How to get started on EME, with audio clips and lots of useful information for beginners by N1BUG

MoonBounce operations - EME operation news, typical moonbounce audio recordings

ISS Realtime tracking - 5 Day prediction table for ISS and find when the ISS will be visible from your QTH by N2YO

SSTV FAQ - Frequently Asked Questions about Slow Scan TV by ON4VT

MIR SSTV Photos - SSTV pictures received from MIR via Slow Scan TV, by WB8ERJ Mike.

SA Watch - SA Watch allows you to monitor and analyze the wandering that your GPS receiver appears to do when it is at a fixed location

Voice Shaper - Voice Shaper is a freeware windows speech pre-processor for SSB transceivers. It receives the voice signal from the microphone connected to the soundcard, and sends the processed audio back to the soundcard in real time by Alex Shovkoplyas, VE3NEA

Spectran - Program designed to do spectral analysis and real-time audio filtering on reception of audio signals for EME, VLF, SETI applications. Offer support for MTHELL, QRSS, DFCW, NDB, WSJT by I2PHD

RDCP/Mac - RDCP/Mac is a communications software package to interface your Macintosh to models of Kantronics TNCs. RDCP/Mac uses the Kantronics HOST mode allowing simultaneous connections on VHF packet and the HF digital modes when using the KAM.

Picture Packet - A Windows95/98/NT control program for Terminal Node Controllers. In its Lite mode it's all the software many packet users may ever need, and it's free. Receive and display of full color, high-resolution images and audio files

PLL2 - 2nd Order phase locked loop design for passive and active circuits. Bode plot, step response, design parameters

FFTDSP  ^pop - FFTDSP is a PC program which can detect weak radio signals in real time. Uses the PC's soundcard and advanced signal processing techniques, extracts and displays weak signals from the receiver audio.

KI5YN QLF Filter - The QLF filter is a microprocessor based interface designed to go between a standard Morse code key and a radio transmitter

High-speed packet 23cm - 23 cm wide-band transceiver for high-speed data or audio by PE1JPD