noise filter

W8JI Technical pages  ^pop - Amplifier, vacuum tube, receiving beverage loop vertical and transmitting antenna system technical information radiation resistance, EH antenna, noise,receivers, and information on keyclicks.

Local QRM reduction - It is not always possible to tackle the sources of local QRM. What remains is trying to reduce the noise level by means of your antenna system. Learn how to reduce QRM and understand how cancell noises by PA0SIM

DX For Me - DX Cluster  ^updated - DXCluster which will allow mobile usage. Now able to manage filter per bands and mode, and to save configuration for specific DX or special event stations.

JPS Communications - Noise reduction products

bhi Ltd - Design & manufacture of Noise Eliminating speakers and modules for effective removal of unwanted noise & interference from SSB, HF, VHF, FM & UHF using new DSP technology

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

Radio Filters.Com - Low Cost FM Notch Filters: Radio Filters.com, manufactures frequency control products including band pass, notch, reject, electronic filters

Mutek - Transverters, amplifiers and low noise preamplifiers

TE Systems - Manuf RF power amplifiers wideband+narrowband for Commercial, Defense, OEM and amatuer markets. Also low-noise rf amplifiers

ARTRA QRP Kits - Lots of homebrew kits, you can buy kits or download as free, Association des Réalisation et Techniques RadioAmateurs. Transceivers, filters, converters, frequency meters, antenna analyzers, ATV receivers, interfaces

Hi-Q Antennas - HF Ham Radio mobile operation antennas manufacturer, W6HIQ, HA5CMG, VE7BOC, HF mobile antennas, screwdriver antenna, coils and filters.

Palstar - Receivers, Antenna Tuners and accessories, antenna analyzers, dummy loads, wattmeters, shortwave radio receivers, baluns, filters

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

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

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.

RadioReader-Pro - Professional software for real-time analysing, demodulation/decoding digital radio-transmission``Demodulation based on the best of the noiseproof correlation algorithms``Demodulation ASK, Morse, FSK, MFSK, CPFSK, GMFSK, FSK4, FSK8, PSK, BPSK, QPSK, FAX

SpotCollector  ^updated - A free application that captures DX and WWV spots from up to 5 internet clusters and a local packet cluster. DX Spots are merged and stored in a Spot Database on your PC, enabling you to monitor, sort, and filter them in real time; known LotW participants are highlighted, as are needed stations. WWV spots are plotted to show SFI, A, and K over the last solar revolution.

Cluster monitor - Cluster monitor is a tool for web and telnet clusters monitoring. The program shows spot history, the latest spots are shown in a separate window with full information about the DX, announcements, WWV propagation, and full sorting and filtering capability. Full support for AALog and AAVoice by RZ4AG, DXAtlas by VE3NEA. Integrated dial-up support.

MultiPSK  ^{updated  pop} - Windows freeware miltimode program by F6CTE that supports BPSK31 QPSK31 PSK63 PSK63F PSK10 PSKFEC31 PSKAM CW CCW THROB 4 bauds THROBX RTTY SITOR-AMTOR-NAVTEX FELD HELL PSK JT65 HELL HF FAX SSTV FILTERS

TCalc - TCalc+ analyses the Noise and intermodulation performance of radio receiver front-ends.

MacDSP - Digital filter for Macintosh computers with a PowerPC processor

DXCluster for iPhone - DXCluster let you know in real time who is on the frequencies and where it was listened the last time. It let you create filters to only see which frequency/CQ Zone/ITU Zone and/or Country and after that you can have an alarm corresponding to a specific Zone or a specific country that raise a popup

Audio Spectrum Analyzer - OscilloMeter  ^pop - Audio Spectrum Analyzer for Real-time, FFT, OscilloScope, Frequency counter, voltmeter, noise and distortion meter, phase shift meter. Multi-Tone Sound Frequency Sweep Generator. White, pink noise.

Variable bandwidth cw filter - As the sunspots return and DX propagation conditions to improve, the age old problem with QRM begins to show up on the amateur bands. Thif filter help you on improving reception

144 MHz preamplifier with BF981 - Design of a preamplifier for 144 MHz with 1 dB NF and 23 dB gain using BF981. This amplifier is using a low cost silicon MOSFET (BF981 from Philips) to give more than 20 dB gain with around 1 dB noise figure on 2 meter.