bandpass filter design

G3SEK's Amateur Radio Technical Notebook - A lot of good informations concerning antennas, filters, moonbounce, and circuitry data.

Amateur Vertical Antenna Calculator  ^{updated  pop} - This calculator is designed to give the vertical length (height) of a particular antenna, for the frequency and wavelength chosen.

T2FD The Forgotten Antenna  ^pop - "Some have called the T2FD a ""squashed rhombic"" antenna. It does bear some design similarities to the non resonant rhombic, but theoretically it is admittedly inferior. However, the T2FD performs well in a modest amount of space."

Citizens Band Mid~West - A very attractive and informative site designed to promote the professional operation and knowledge of Citizens Band Radio

Whiskey Alpha DX group - "Formed in 1996 in the USA, the ""Whiskey Alpha"" group has members in a few different country's and is growing every day. We provide all members with a ""personalized"" QSL card design. Membership has no annual dues, and is for life."

Workman Electronics - Amateur radio accessories, power supplies, tvi filters, speakers, microphones, swr meters, preamplifiers, switches, cable and connectors,

E-Z-O Antennas - A new beem antenna design improvement over the cubical quad

Dunestar Systems - Manufacturer of single band and multiband transceiver bandpass filters for HF. High pass filters, two radoi headphones mix and switch, 6 meter portable antenna, antenna remote switching and steering.

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

Timeware tech. - Amateur Radio Products, Noise Reduction Filters, Data Controllers, deviation meter, Software, DSP-RTTY

Almost all digital electronics - This site is dedicated to electronics hobbyists, engineers, and Radio Amateurs interested in circuit design, homebrew and kit projects.

RMS international - RMS International, italian distributor of Alcava batteries and power supply, since 1975 manufacture power amplifiers, watt meters, antenna tuners, TVI filters and other accessories for hams and cb radio

AEA - AEA Technology Inc. is a pioneer and leading manufacturer of RF and cable test equipment for the wireless, Telco, CATV, NMR & MRI, RFID, telemetry, aviation, commercial, military, and two-way radio industries. Produces SWR Meters, Pre Amplifiers, filters, power meters and antenna testing products

International Components - International Components Corporation has an extensive range of electronic components consisting of audible signal devices, speakers, microphones, capacitors, electron tubes, connectors, and accessories designed in recognition of the diversity of applications and special characteristics encountered by designers in today's complex world.

Novel filter for sat working - Elimiate QRM when working with satellite antennas

NA7EM QSL Card design - Offer custom design and printing of extremely high quality, very affordable, QSL Cards.

Antenna Maker  ^{updated  pop} - Antenna design program for Quads, Yagis, Inverted Vees, J-poles, Trap Dipoles and more.

Quickyagi - This is the place for downloading the latest DOS version of Quickyagi the freeware yagi modeling program with auto-design & optimize.

RXClus - RXCLUS is a free amateur radio software especially designed for the DX'ers and SWL's wanting to receive the informations transmitted by packet radio on the DX-cluster system. It supports also telnet protocol.

DXbase - Professional Logging Software for Windows 95/98/NT. A separate version is available for DOS. Full featured logging, HF radio control, Internet Packet, VHF Packet, Label Designer, Report Designer, and a lot more.

DX 4 Win  ^pop - DX4WIN is an easy to use, yet powerful logging program for every ham. It has been designed for the the serious and the casual DXer.

LogWindows - Log X  ^updated - Log-X formerly LogWindow is a Windows based software program designed for the specific use of Amateur Radio operators to keep a log of the contacts that were made with other radio operators around the world, designed to be used in Amateur Radio contests, Emergency situations, and for general record keeping of conversations. By SCO Inc

Universal LF/MF Preamplifier - "A ""Universal Antenna Preamplifier"" design, in Web page form. Works with long wires, loops, or whips. For longwave and medium wave."

40MHz Frequency Counter Module - Design for a very low cost 6-digit frequency counter module using of the shelf components

K1TTT Technical Reference Priority listing - Technical reference about Accessories, Amplifiers, Antennas, Cable and Connectors, Filters, Geography, Grounding, Gunk, Matching Networks, Projects, Propagation Info Radios, RFI/EMI, Rotors, Station Setup, Towers.