fir filter

W7AV 40 Meter Half Square - These antennas offer big gun DX performance on the low bands, yet they are surprisingly simple to build. Try one- you will like it!

The K6STI Receiving Loop - This relatively unknown antenna does an amazing job pulling weak low band signals out of man-made noise backgrounds

AMANDX Dipole - The longwire antenna is a very effective antenna for the listener who wants to cover all of the shortwave bands from 530 KHZ to 30 MHZ.a

6m Half wave vertical - This antenna is very useful for receiving or scanning purposes, but you can use it for transmitting, too. It is 2,94m long and has a pi-configuration (Collins-Filter) for the matching.

Saskatoon Scanner - Live Saskatoon police and fire dep. scanner

Dallas police live scanner  ^pop - Listen to the Dallas Ambulance, Fire & Police live scanner radio feed

Scanner Chile - Scanner Chile is a System online where you can listen to the Departments of Firemen of the Metropolitan Region Chile

PSKMeter - KF6VSG pskmeter page, describing the hardware, software and firmware for a monitoring device for psk31 transceivers that automatically maintains the sound card level to give maximum drive to the transmitter without introducing distortion.

International Crystal Manufacturing Company - International crystal manufacturing provides quartz crystals, oscillators, precision crystals, filters, tcxos / vctcxos, qcm crystals, and other frequency control products. read details about our crystals and frequency control products and services.

Nye Viking - Antenna Tuners, morse keys, keyers and filters

UHF Reject filter - This filter is a 0.1 dB Tschebychev lowpass with a rejection of 90 dB or better at 430 MHz, and 0.2 dB insertion loss at 72 MHz.

FT-1000D: The G3TKF Synchro Mod - If you have an FT-1000 with the BPF-1 option, and are into HF weak signal DXing, this is for you. Although not for beginners, it should be no problem for hams with some home building experience.

AF Filter for FT-897D - AF Filter modification for the Yaesu FT-897D by Petr OK1FIG

NSW Emergency Service Scanning - Scanning information (frequencies and talkgroups) of the emergency services in NSW, such as the NSW Police Force, NSW Fire Brigades, NSW Rural Fire Service, NSW State Emergency Service and Ambulance Service of NSW.

LouisvilleScanMan - One stop site for scanner users in Louisville Kentucky. Frequencies,10-Codes,Unit Numbers,Scanner News and more. Covering Fire,Police,EMS,Disaster,Civilian Emergency,Aviation,Railroad and other services.

All American - Distributor of electronic components, ull range of semiconductors (active components), including relays, circuit breakers, transistors, diodes, memory devices, microprocessors, microcontrollers, and other integrated cuircuits, as well as passive components, such as capacitors, resistors, inductors, and electromechanical products, including cable, switches, connectors, filters, and sockets.

JavaScript Electronic Notebook, K7MEM - It consists of a group of JavaScript® driven web pages that are intended for use as a quick reference for Ham Radio operators or just anyone interested in electronics. Offer calculators for Resistors, capacitors, inductors, power supplies, filters, attenuators and antennas

Elsie - Filter Design - Filter design software. Elsie is an uncommon commercial-grade lumped-element ("L-C") electrical filter design and network analysis program, directed toward the engineer or technician involved in that line of work.

SVC Filter - Filter design software. A program designed to expedite the design and analysis of lowpass (and highpass) filters with nearest 5% component values. SVCfilter is 32-bit Windows electrical filter design software nicely written to help the radio amateur, technician or engineer design and analyze lumped-element lowpass and highpass filters.

Helical - A graphics-intensive bandpass filter program based on the helical resonator.

FreqTweak - FreqTweak is a tool for FFT-based realtime audio spectral manipulation and display for Linux. It provides several algorithms for processing audio data in the frequency domain and a highly interactive GUI to manipulate the associated filters for each. It also provides high-resolution spectral displays in the form of scrolling-raster spectrograms and energy vs frequency plots displaying both pre- and post-processed spectra.

A diode-switched band-pass filter - High speed silicn diodes work well as RF switches. This article describes how to use diodes for selecting two or more filters ARRL QST article by W1FB

Band filters by PA9M - Band filters for PA6Z made by PA9M, designed by W3NQN.

Coaxial Stub Filters - Coaxial stub filters used at W7GJ

Filters and Ferrites in EMC - This article is about the characteristics and use of various filters and ferrites for solving amateur radio electromagnetic compatibility problems involving breakthrough of amateur signals into domestic equipment such as television sets, video recorders stereo sytems etc.