noise filter

Comparison of Beverage antenna - A ranking of receiving antennas based on noise being evenly distributed in all directions. These rankings are most accurate in the frequency range of AM broadcast, 160 or 80 meter bands

HC DX Feeding that antenna - Avoid noise, boost performance: make a perfect coax feed line. The perfect feedline, How to install your antenna properly, How to get the best from your coax

A Small Wire Loop Antennas for 160 meters  ^pop - Low noise, receive only coax loop antennas for 160 - 10 meters HF bands

Interference Cancelling System - The use of interference signal cancellation has been around for some time. The idea is to use an auxiliary antenna almost any random length of wire in addition to the main receiving antenna

W5JI Boatanchor Haven - Dedicated to the Care and Feeding of BoatAnchors, includes some Drake catalogs, and 1968 Collins Mechanical filter catalog pages

DXWatch  ^pop Priority listing - Cluster spot filter service and webcluster, receive your filtered spots via email or icq.

TX RX Systems Inc - TX RX Systems Inc. manufactures signal boosters, rf antennas, transmitter combiners, cell enhancers, land mobile radios, duplexers, receiver multicouplers, bidirectional amplifiers, bda, rf amplifiers, rf filters, rf cavity filters, rf combiners, rf components, in building rf coverage, repeaters, repeater amplifiers, rf management equipment, rf systems, and rf solutions. TX RX Delivers Reliable Solutions.

DCI Digital Communications - Band pass filters, for radio frequency interference problems.

AR2 communications - Complete catalog of low noise preamplifiers and microwave Gunnplexers.

Ameco - Text books relating to amateur radio (HAM radio), highpass and lowpass power filters, transmitter test loads (dummy loads), study tapes and disks to learn morse code, transceiver preamplifiers, antenna signal boosters.

PROCOM Antennas - Manufacturer of communications antennas, bandpass filters, RF combiners, receiver multicouplers, diplexers, duplexers, RF connectors, RF circulators, RF isolators, RF couplers and SWR meters

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

Power Line Noise - I have a shortwave radio, but I get nothing but a loud buzzing on it. What's wrong?

VLF-LF And the Loop Aerial - The article discusses the theory of loop aerials for receiving and how they reduce the level of local noise. A Loop Aerial is described suitable for use on the LF and VLF bands together with a circuit of an interface loop tuner and preamplifier. The discussion extends to the problems of amplifier noise and the advantages of tuning the loop.

Morse code ringtone generator - This page converts text into a morse code ringtone playable on most mobile phones.

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

BR-universal-Filt - Freeware real time DSP filter particularly for applications of amateur radios , IIR, FIR filter, low-pass, high-pass, band-pass filter, band suppressor (notch filter) individually adjustable

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

Filters for NDB reception - RF Filters to help with NDB reception problems

Low noise preamplifiers  ^pop - Lot of projects of preamplifies from HF to VHF and UHF by yu1aw

23 cm GaAs FET preamplifier - On 23cm the best way to obtain a good RX-sensitivity is to use a GaAs-FET in the front-end, since these devices show very low noise figures.

Receive only processing equipment - One of our most popular products, receiving preamplifiers are used for achieving top signal band performance in competition operating, low noise longwave reception, repeater applications into the UHF region, or lab use

TVI filters - These filters are in use by hundreds of VHF weak signal operators and have been proven to be an effective solution for fundamental overload problems.

6m High Pass TVI filter - Are you suffering from TVI? Then why not try this filter for size. It is a three-stage high-pass filter that blocks low-frequency 50MHz signals while letting through UHF TV.

Antenna Noise and Signal Cancelling at LF - By using the signals from two antennas, controlling their relative amplitudes and controlling the phase of one of them, unwanted signal or unwanted noise can be phased out. Circuitry is described which uses the signal from a wire antenna to provide selective cancelling against the signal output from an LF loop antenna.