audio filter

18SD001 live streaming - Live streaming audio from 18SD001 locator KM18VA Athens Greece usually online during week-ends

K5MQ Ham Radio Audio Recordings - Recordings of DX stations from around the world SSB and CW.

Amateur Radio Techniques - RF Filters an adjustable j-pole antenna manufacturer based in greece

Micro908 Kit - A re-usable control & computing platform for antenna measurement, PSK31 digital modems, audio filtering, signal source & VFO, memory keyer by AMQRP

Trilithic - Broadband instruments, R and microwave components and filters, field analyzers, spectrum analyzers

PC Connection Cable for Yaesu FT100 - A simple cable for the yaesu FT-100 or FT-100D and a PC by interfacing audio and serial ports. In Italian

Natural Radio Listening: Streaming Audio - A page about fascinating Very Low Frequency and natural radio, with lots of streaming audio links from remote receivers. Some experimental stereo pairs around the world.

The Tube Center - Supplying over 2000 different vacuum tube types, valves, grid caps, sockets and capacitors. It is easy for Antique collectors, Ham radio operators, audio enthusiasts, broadcast enthusiasts and amateur radio hobbyists to buy, sell and trade vacuum tubes, electron tubes, audio tubes, valves, grid caps, sockets and capacitors

ABCVacuumTubes.com - ABC Vacuum Tubes is dedicated to providing Ham radio, amateur radio operators, antique radio enthusiasts, audio professionals and hobbyists the ability to choose from an inventory of over 3.5 Million Vacuum Tubes on hand under one roof.

The RF Shop - Repair HF, VHF and UHF amateur equipment and provide complete repair service for All Audio and .PA Equipment.

AutoRec - AutoRec is windows freeware time based automatic recorder - player for radio broadcast. Auto Recorder will record or play wav audio files, and execute batch or other executable application programs at scheduled times. The primary use for Auto Recorder is automatic, unattended recording and playback of network or other satellite-delivered radio station program material.

SweepGen - SweepGen turns a PC into an Audio Oscillator and Sweep Generator which can be used for testing audio or educational purposes. In conjunction with audio test instruments, you can make frequency response plots. SweepGen uses the sound card in your PC to produce sinewaves

Sine Wave Generator - Freeware windows Wave Generator use the sound card's output as sine wave output. A built in sweep algorithm is used by audio hackers to measure frequency repsonses of their amplifiers

QuickMix - Freeware windows program that allows you to store configuration of your audio mixer in a settings file, and to restore the mixer to that state whenever you want. Useful for digital mode operations where different dsp programs may require different audio in and out settings.

HI-FI Audio with Kenwood TS-850SAT - Setup guide for DSP-100 and TS-850

Diplexer design notes - Standard diplexer design is based on singly-terminated Butterworth filters.

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.

The NVARC Ugly ¯ Filter Project - Project to build sets of band pass transmitting filters for reducing the interference between HF transceivers operated in close proximity

Narrow Band-Pass filter for HF - Band-pass filters can be critical components in competitive stations. This setup may help put your station on the map.

Clean Up Your Signals with Band-Pass Filters - These inexpensive, easily built filters can be the buffer you need between the signals you want to hear and send and those you don’t!

Clean Up Your Signals with Band-Pass Filters part 2 - Part 2—You’re now much closer to saying goodbye to your unwanted signal problems!

Band-Pass Filters for HF Transceivers - Do your multiple-transmitter field day or contest efforts suffer from intrastation interference ?

K2TR Coax Stub Filters - Multi transmitter filters

Easy bandpass filters - Quick and easy bandpass filters for receiver input by George Dobbs G3RJV

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