filter

Chokes Explained - A "choke" is the common name given to an inductor that is used as a power supply filter element. They are typically gapped iron core units, similar in appearance to a small transformer, but with only two leads exiting the housing

Shortest Vanity Callsigns  ^updated - This is a service for finding the shortest available vanity callsign in your amateur radio class. It filter through all possible callsigns and provide just the unused ones weighted by their length in morse code or their actual number of letters.

Accute Micro - China supplier of ceramic bandpass filters in standard resonator sizes of 2~6mm , 8mm , 10mm and 12mm with freqency from 400Mhz~4Ghz and sections 2~10

Duplexers for Ham Radio repeaters - We produce duplex filters and antennas for 2m,70 cm and 23 cm repeaters.

Garth RF Filters - ATV Filters, RF filters dealer

SWL DX Cluster - Web cluster for swl's. With many features, including filters, search, SWL Database, lookups

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.

Audio processor for SSB transceiver - This circuit consists of microphone amplifier and a high pass filter. Suitable to improve signal readability.

A low cost UHF/VHF duplexer - Duplexers for dual band radio are usually high pass filter and low pass filter combined in the same box. This circuit is a design within a cost of US$10.

Second-Harmonic-Optimized Low-Pass Filters - Sometimes we need a little more output filtering than traditional designs offer. Look at a new filter that can give you that extra boost. QST article by W3NQN

500 KHz Low Pass Filter - This article describes a shielded low pass filter with a cut off frequency of about 500 KHz. It is built with components suitable for receiving, and was designed to use in front of a low frequency receiver for LOWFER work.

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.

VHF signal generator - a simple VHF signal generator in order to measure the characteristic of low pass filter.

A single board no tuning 23 cm transverter - This transverter uses bandpass filtering with printed hair-pin filters. By KK7B