low pass audio filter

Cubic Quad  ^{updated  pop} - The cubic quad is a very popular way to get reasonably high gain and excellent front to back ratios as well as low angles of radiation for without going to extreme heights. Includes design for 2 6 10 12 15 meter bands

QM7 7 elements 144 MHz Yagi-Uda Antenna - The QM7 antenna is a simple 7 elements Yagi with 3.70 m boom length for the lower 144 MHz SSB/MGM band, used it mainly for Sporadic-E and MS contacts. It exhibits a forward gain of 11.35 dBd; i.e. 13.5 dB forward gain over the isotropic radiator, while the F/R is about 12.5 dB

Why terminate a Beverages - Terminating the far end of the Beverage makes it unidirectional. It also makes the receiving angle of the antenna lower.

Thinking about Ideal Loops - Loop antennae have been used from ELF to UHF since the beginning of radiocommunications. At low frequencies, the main problem for loop antennae is to have enough sensitivity; the antenna being very small respect to the wavelength the collected energy is also small. To increase the output level the loop may be made resonant, so loosing it%u2019s intrinsic aperiodic characteristics.

Effective HF Mobile Antennas - Effective HF Mobile Antennas Keith WB2VUO, explains difficulties on gaining antennas efficiency on lower bands with mobile antennas.

43TR299 Geoff - Small station in northern Australia running Quad antenna, info and audio files

Lowndes County Amateur Radio Club - Lowndes County Radio Club, ARES, Community Service oriented club.

Ham Radio Audio Stream - Ham Radio FM repeater audio stream live from Germany

ON4AOI Automatic Band Decoder - Automaticaly select the correct antenna and bandpass filter, by ON4AOI

New Sensor Corporation - Distributor of Sovtek, other current production vacuum tubes, and NOS tubes. Distributor of electronic parts for audio and musical instrument amplifiers. Manufacturer/ Distributor of Electro-harmonix effects.

Fax480 - FAX480 was developed to provide for relatively high resolution image transmission on HF, VHF, and UHF amateur radio bands. FAX480 was designed to bridge the gap between conventional slow scan television (SSTV) and conventional facsimile techniques.

Slow Scan TV beyond HF. - Dedicated to the promotion of SSTV on VHF.

Ham Radio Audio and Resources - EchoLink and IRLP Internet Radio Linking Project Node's, Hurricane Watch Audio Feed's and Info, Live Scanner/Other Feed's from the USA, Local Ham Frequencies, Online Receiver's, Shoutcast Live Audio Feed's from the USA, Southern California Frequencies and more

Radio Dr. - Professional electronic repairs on old & new CB's, Ham & Marine Radios and more. Low rates, thousands repaired for other shops.

Vacuum Tubes Radio - Vacuum Tubes and Radio Tubes Our specialty. We carry over 5,000 radio and vacuum tubes in stock every day and we ship world wide. Tubes for industry, music, ham radio, the audiophile.

N9TEW tubes - N9TEW is supplier of vacuum tubes for ham,audio & antique radio purposes.

Electron Tubes and Vacuum Tubes for Industry - Electron tube and vacuum tube stock-list with prices 4. Audio, broadcast and industrial tubes, triodes, tetrodes, thyratrons, ignitrons, vidicons and CRT's, microwave devices, nixies and receiving types + Bird RF devices and test equipment. Quality tubes at reasonable prices with many hard to find items available

SlowHell - A MT Hell dos transmitting program by DF6NM

STSPLUS - STSORBIT PLUS, usually known as STSPLUS, will track the space shuttle or any satellite for which orbital data (TLEs) are available. A brief description of the program and several screen capture examples follow the links for downloading the program files.

Satel939 - This program allows the pursuit of satellites in real time or in wished dates as well as the forecasts of passage and the visiblity between satellites. Three lists of 15 satellites, choiss among 50 in memory

HalloSat AO-40 Special Edition - Freeware Tracking Program for AO-40.Based on Windows timesetting, thus automatic switching between normal and daylight saving time. Preview listings with a view to the passband schedule, to the squint angle and elevation. Integrated frequency calculation for transmit frequency (uplink) depending on receive frequency (downlink) with a view to dopplershift. CAT – Control for all Icom – Transceivers without IC-821.

PCRSat - a PREDICT client application written by Vittorio Benvenuti, I3VFJ, allows operation of an ICOM PCR 1000 receiver in a satellite communication environmenta PREDICT client application written by Vittorio Benvenuti, I3VFJ, allows operation of an ICOM PCR 1000 receiver in a satellite communication environmenta PREDICT client application written by Vittorio Benvenuti, I3VFJ, allows operation of an ICOM PCR 1000 receiver in a satellite communication environment

Ballistic simulator Orbit - Ballistic simulator "Orbit" allows the physical principles of the motion in the gravitational field of the Earth to be demonstrated and learned. You can calculate with this program the ballistic trajectories of the thrown bodies and orbits of spacecrafts and visualize the astroballistic situation on the flat map of the world and on the rotating globe in the real time

TCube - TCUBE is a combination of a Spectrum Analyzer and a Two Tone Generator, with optional quadrature outputs. It can be used for measuring the intermodulation behavior of an audio circuit, and as a general purpose tool

Kenwood TS-950S RF gain mod - The Kenwood TS-950S and TS-950SD HF transceivers are fine radios. However, many, if not all, of them were produced with a design flaw which allows the RG GAIN control to cease function in the presence of a strong signal IF the AGC has been turned OFF