audio filter

Edmonton Fire Department Live - Listen to live audio from the Edmonton Fire Department.

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

Ivie - Manufactures automatic mixers, analog and DSP signal processors, room combining and matrix mixers, and audio test equipment for just about any customer application.

LCLAYOUT drawing software - Simple inexpensive program that allows L-C filters designed by PCFILT or S/FILSYN which are to be built using air wound inductors and single layer capacitors cut from alumina or duroid substrate materials

ALK Engineering - Alk engineering - filter design software and consulting

FILPRO - The most flexible and powerful Microwave and RF Filter and Multiplexer Design Software

Nuhertz Technologies - Leading supplier of low and high frequency electronic filter design products for the design of wireless telecommunications equipment, semiconductors and more

Omicron filter design - Electronic filter design software by omicron is the best for developing active filter, passive filter, and digital filter - check out our products and ordering information.

Filter Wiz Pro - Schematica software filter design program

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.

ScopFIR - Free windows comprehensive tool for Finite Impulse Response (FIR) filter design

FilterCAD - A free computer aided design program to help users without special expertise in filter design to create filters using Linear Technology's monolithic filter ICs. With FilterCAD, you can design lowpass, highpass, bandpass and notch filters

AADE Filter32 - ADE Filter Design and analysis is a free for download windows program to design filters

DXFile - Windows shareware logging program, offer several features like packet radio interface, web cluster, grid square, beaming directions, qsl manager lookup, dx spot filtering by F6GQK in french.

1.8-54 Mhz Low pass filter - An easy to make HF low pass filter form high power by k8cu

Homebrew a CW Filter - An home-brewed morse code CW filter with a central frequency of 800hz and a variable bandwidth from 230hz to 26hz by F5RDH in french.

Interdigital bandpass filter designer - Fill out the form to design a bandpass filter as described in the January 1985 issue of Ham Radio Magazine. These filters are generally limited to frequencies above 200 MHZ because their size is slightly longer than 1/4 wavelength

Interactive Digital Filter Design - This is an interactive filter design package, for designing digital filters

LC Filter Design - This is an interactive design package for designing analogue (i.e. hardware) filters made of inductors and capacitors (Ls and Cs).

Online Microwave Filter Design and Analysis - This site is dedicated to design and analysis of micro- and millimeter wave filters from 0.5 to above 100 GHz.

The Ladder Filter - Article by Lloyd Butler VK5BR

TVi Basics - making filters - TV Interference filters, making TVI filters, coaxial filters to eliminate TV interferences caused by radio frequency

5th order High Pass VHF Filter - Sometimes many VHF-UHF modern transceivers have problems with BROADCAST Interference and CROSS-modulation from FM commercial broadcast stations this article shows a simple Batteworth HI-Pass VHF Filter to reduce this problem

Designing Op Amp Audio PreAmplifiers - Design guidelines for Op Amp audio preamplifier circuits by Mike Martell N1HFX

Sound Card Interface by VK6YSF - Presented here is a transceiver to computer sound card interface complete with automated transmit key function. A sound card interface is simply the audio coupling of a computer soundcard and a transceiver to allow various computer applications that send and receive SSTV, RTTY, PSK31 and other similar modes based on soundcard generated signals.