mode identification

Practical Guanella 1:1 balun - This article proposes a lossy transmission line model of a practical Guanella 1:1 balun that is effective for all frequencies within and immediately adjacent to the pass band

Guanella 1:1 VHF choke balun - A model of a Guanella 1:1 VHF choke balun using a FT140-61 core

Noise Reduction on 40m Priority listing - DF9CY implementation of W1HIS suggestion of inserting a common mode choke into a 40m antennas feed-line.

D-Star presentation and sounds - A powerpoint presentation of the D-STAR operating mode by K7VE includes d-star sound samples

YouTube - What the HELL? - Hellschreiber is an interesting ham radio mode developed back in the 20s. It is a bit strange and different, but fun. I'll explain what it is, then I make a couple contacts during the Hellschreiber contest.

Farallon Electronics - PACTOR mode radio modems and accessories, performance sailing electronics and innovative hard to find parts. Audio cables, packet cables, usb to serial converters

HxPI Radio - First Steps Radio - First steps in science and technology. First steps radio. Color graphics and simple explanations of basic concepts in radio. An introduction to radio communication as a technical hobby. Resources for teaching, training, learning, self-study. Modern morse code. Morse code in the 21st Century. Morse code as a technical hobby. Morse training and practice material. Exercise files to download.

A History of Hellschreiber - The first really successful Facsimile mode, is as old as electronics itself.

Digital modes Babel Tower - A review of ham radio digital modes with watefall differences between PSK RTTY Hellschreiber MFSK Olivia JT65A and digital voice by HB9TPL

DStar- is anybody else worried about this? - D-Star is being promoted as a new digital voice transmission mode "For the second century of Amateur Radio" - but does it really fit into the spirit of the hobby?

An Introduction to Hellschreiber - Feld-hell club promoting the use of all hellschreiber modes on the amateur radio bands.

W1TAG WD2XES WE2XGR/3 - Experimental Stations Run by W1TAG WD2XES has been used to study LF antenna design, propagation and communication modes. Signals from WD2XES have been copied as far away as Russia.

Low Frequency Transmission Modes - Article by W1TAG on operating modes used on low-banding. The 2200 meter band (135.7 - 137.8 kHz) is only 2.1 kHz wide, so voice work on SSB or AM is out. Find out the best modes on LF

Keyboard Modes for 600 Meters - Evaluation of various operating modes on 600 meters

Olivia, the Magic Digital Mode - Olivia MFSK digital communications are becoming popular in amateur radio because Olivia is one of the most robust methods of text keyboarding, that can perform superbly for long distance communications. Olivia frequencies, format and software

Operating Meteorscatter - Meteorscatter (MS) describes a propagation mode whereby the signal is reflected from rather small ionised patches in the E-region of the ionosphere.

An Introduction to 24 GHz - Article provides a guide on how to use 24 GHz band and what to expect, including Active modes, equipment, propagation and antennas for this band in by VE3SMA

Xperto Antenna Software AN-SOF - XPERTO is a software for the modeling of antennas and 3D arbitrarily shaped wire structures. Xperto computes the electromagnetic response of wire antennas, including radiation and scattering problems.

cocoaNEC - cocoaNEC 2.0 is an opensource Mac OS X application intended primarily for the design and modeling of antennas by Kok Chen, W7AY

MiniErrorCorrection Program - This simple program was written as a possible utility for those attempting to communicate using digital modes via paths that are intermittent and tenuous such as Aircraft Scatter at VHF and Low Earth Orbiting Satellites by G3PPT.

MultiDem - USB LSB AM Modem (Modulator/Demodulator) for SdR and DSB (direct conversion) transceivers by F6CTE

HF software digital modes for linux - This software allows a standard PC soundcard to be used as a shortwave data "modem". The whole processing is done on the main processor CPU. Support RTTY Amtor (Sitor) and Pactor 1 by Thomas Sailer, HB9JNX/AE4WA

SPLAT! for Windows - This free software is useful for visualizing terrain and performing Longley-Rice path loss and coverage prediction using the Irregular Terrain Model. A Windows port of the Linux-based SPLAT by John Magliacane.

5th order High Pass VHF Filter - Sometimes many VHF-UHF modern transceivers have problems with BROADCAST Interference and CROSS-modulation from FM commercial broadcast stations this article shows a simple Batteworth HI-Pass VHF Filter to reduce this problem

Sound Card Interface by VK6YSF - Presented here is a transceiver to computer sound card interface complete with automated transmit key function. A sound card interface is simply the audio coupling of a computer soundcard and a transceiver to allow various computer applications that send and receive SSTV, RTTY, PSK31 and other similar modes based on soundcard generated signals.