dc filter

Band Filters - Experience of band filters, for a contest multi operator enviroenment

Receiving antenna for low bands  ^pop - K9AY loop antenna installed at PA6Z Contest group. This is a receiving antennas for the low bands (160m, 80m and 40m). Include schematics and info on a building the control box, preamplifier and low-pass filter

DCTL Portable Antenna - A Low -Power, Distributed Capacitance Twisted Loop , indoor portable HF antenna by Monty Northrup, N5ESE

Oklahoma Vintage Radio Collectors - Promote the preservation of the history, technology, and equipment of the early days of radio broadcasting and communications

Antique automobile schematics - Antique automobile radio repair and schematics

WAEDC-Contest - WAEDC contest page

DARC IARU-Region-1-Fieldday

WAE-DX-Contest - The Deutscher Amateur Radio Club (DARC) invites radio amateurs world wide to participate in the annual WAE-DX-Contest. CW SSB and RTTY Contests

Boston-Area University Police Radio - Police and Security Broadcasts at Harvard University, Boston-Area University Police Radio. Cambridge; Boston.

Setting up a live broadcast on the internet

Low Power Radio and Broadcast Company - Manufacturers of high performance low power am transmitter products: sstran amt3000, bc-100, and the mw-250. for home and professional use.

RFSM-2400 Digital Mode - A recent digital radio protocol. Based on a freeware soundcard-based Radio Frequency Software Modem. Work under standart MIL-STD-188-110A. Maximum speed 2400 bit/second. Signal bandwidth: 0,3-3,3 kHz (standard mode) and 0,3-2,7 kHz (non-standard mode).

APRSTV.com - A video podcast about aprs, the automatic position reporting system, used by amateur radio operators.

Adjusting Filters for PSK31 - Screen shots of what happens when you do and don't get it right. By Dick Stevens, N1RCT, a very clear, helpfull and comprehensive document.

FT-897D Modification sheet - Lot's of FT 897 modifications in a single PDF file

RF Filters - MS DOS Program for calculations of HP, LP and BP filters at VHF and UHF frequencies up to about 800 MHz by YU1AW

SlowFeld XP - Free windows program by G3PPT that permits RTX of FeldHell

Morse Tone Encoder - Generates Morse tones using the Soundcard. A neat tool for sending out short sequences of Morse tones.

QSL Card Imaging - A database which allows the user to store and catalog QSL cards

DTMF encoder - Generates dial tones using the Soundcard. A neat tool for sending out short sequences of DTMF tones.

Soundcard Audio Tools and Toys - Soundcard audio tools and toys, experimental ideas and utilities. Signal Generator, Frequency-counter / instrument-tuner, Real-time Spectrum Analyser

Interferences and filtering - General information on Filter passbands, interferences, TVI and RFI problems

SoundCard Packet TNC PC to Radio Interface - Computer sound card packet tnc to radio interface. david stansbury kb3kai home-brew version of this soundcard to rig adapter

Interfacing to PC soundcards - General electronic topics on interfacing to PC soundcards by epanorama.net

A Cable Construction Trick - If you have several TNC and radios this trick can be usefull for you