audio filter

Gisela Dierking NF/HF-Technik Germany - Many interessting accessories, like unversal audiofilter, Mixer interface for sound card, highvoltage powersupply,accessories for 706, hamradio vacation, and more

Eurofrequence Dierking NF HF Technik - UFB Hamradio audio filters and more accessories

Timewave - Sells leading-edge voice and digital communications products to the world-wide military, government, industrial, and amateur radio marketplaces. Bluetooth Remote Audio/PTT, Rig Controller with Audio & PTT , HamLinkUSB Rig Control, Noise filtersm antenna analyzers, Multimode Data Controller, TNC, Packet Radio Terminal Node Controller. USB2RS232

MFJ Enterprises  ^pop - MFJ manufacturer of ham radio antenna products, antenna tuners, antenna analyzers, morse code & CW, SWR wattmeters, antenna accessories , power supplies, audio filters, TVI filters, baluns, coax switches and more

Davis RF - provide electronic and electrical wire, cable, RF connectors, DSP audio filters, rope, non-conductive guy cables for aerial or tower support; plus sundry aerial related parts

Idiom Press - CW keyers, Logikey, and antenna rotator controll like rotor-ez, and active audio low pass filters.

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

Sherwood Engineering Inc. - Cooling kits, drake filters, speach processors, audio switch boxes, synchronous AM detectors,

CW Command Post - Replace four separate accessories keyer, keyermemory, audio filter, and audio amplifier-- with one box containing allfour and providing for multiple inputs and outputs. N1FN CW CommandPost A not very original CW operating accessory "put together" by N1FN

Getting started on RTTY - A complete guide from the station setup, rtty software customization, tips on tuning rtty signals and setting the proper audio level and filters by Andrew G8GNI M5AEX

Timewave manuals - Timewave Documents for User Download, PK-900 Multimode Data Controller, PK-232 Multimode Data Controller, DSP-232 Multimode Data Controller, DSP-9 Noise Reduction and Bandpass Filter, Audio Signal Processor and Noise Reduction Filter, Audio Signal Processor and Noise Reduction Filter for Yaesu SP-5 and SP-6 Speakers

IC7000BKT Icom IC-7000 CAT Control - CAT Control for Icom IC-7000 for windows. Management and synchronization of all memory bank, Management filters, volume, tones, DUP, DTCS, import export, audio recording and log frequency and signal,Auto CQ audio for repetitive calls

Eurofrequence Dierking in Germany - Accessories, like universal audiofilter, Mixer interface for sound card, highvoltage powersupply, accessories for 706, hamradio vacation,Roger Beep, Microphons, Headsets and more. Please look

HamCalc v1.3  ^pop - By G4VWL, HamCalc is collection of calculators for radio amateurs: Antenna ERP calculations. Attenuators. Audio Filter design.Coil Winding. Decibels. Great Circles map and calculator HF Filters HF Traps Metric conversions OP Amps QRA Locator to Latitude/Longitude (and back) Radio Horizon calculator Resonance Satellite orbit calculator Timer calculations (555 timer)Zener Diode calculations

Free programmable DSP-Filter  ^pop - Free programmable LOW/HIGH/BANDPASS FIR filter in the audio range 0-4kHz

EchoFilter - EchoFilter uses the soundcard of a PC to process income audio signals in real-time. The narrow filter bandwidth allow the extraction signals and sounds from the audio signal that may normally be close to inaudible. It is intended for radio HAMS, hobbyists, researchers, scientists and students in the DSP field.

WD6CNF DSP Filter - Audio Digital Filter, two bandpass filters, three notch filters, two noise filters graphical setting of filter center frequency and bandwidth Drag vertical lines on top of signal, Microphone input, speaker output Mono, 5 kHz bandwidth

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.

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.

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

Spectrum Lab  ^pop - DL4YHF's Audio Spectrum Analyser Spectrum Lab or Speclab started as a simple FFT program running under DOS a long time ago, but it is now a specialized audio analyzer, filter, frequency converter, hum filter, data logger and more. Can be used for MTHELL QRSS, DFCW, PSK, MSK, Castle

HamView - A freeware program to dig out weak signals buried in noise, functionally similar to the excellent FFTDSP of AF9Y, but with the added bonus of real time audio filtering of the incoming signals. Just point and click with the mouse, and the selected signal will stand out from the QRM and noise.

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

Hombrewing an HF Transceiver - This page will describe the construction of a multi band SSB transceiver with all its components Band Pass Filter, Oscillator/Modulator unit, RX/TX Mixer TX Amp I.F. Amplifier AGC VFO Driver amplifier Receive audio amplifier Final amplifier Low pass filter Digital display and VFO stabiliser

The smk-1 on 20m - Taking the venerable SMK-1 design to 20m and adding an RF amp, audio filter, and a TiCK Keyer ... by Wayne McFee, NB6M