tm271a cap/mars mod

SWR: Maximum allowable VSWR - VSWR (voltage-standing-wave-ratio) represents the degree with which an antenna is "matched" to the system impedance. Most modern antennas do not require any tuning for optimum performance. VSWR is one of the easiest parameters to measure and VSWR meters are becoming very popular antenna installation tools

Mobile Helix Antennas for HF - Normal mode helix antennas for HF mobile. Photos andn plan for a 20 meters mobile helix antenna by N2MH

Modified Buddipole for 40 to 10 Meters - This is modified version of buddipole antenna, using vertical wires instead of telescopic ends by ks7j

KS7J 5-band Cubex Quad - KS7J's Cubex 5-Band Quad, tests, pictures and modification of this five bands quad antenna

45SD105 Vlada - Personal web site of a freebander, info on 11m digital modes, pictures of antenna projects

G0GJV VHFLog - VHF contest logging program, run in DOS mode

RACOM - Radio modems - RACOM is a Czech company specialized in design and production of radio modems and other devices for wireless data networks for radio channels from 140 to 900 MHz. RACOM radio data networks are suitable for data transfer in telemetry & SCADA applications, transaction networks, security systems, IP networks and firts of all mobile tracking and fleet management.

Telewave - Telewave's innovative engineering produces the industry's toughest antenna systems. Yagi, Fiberglass Collinear, and Dipole models are available from 66-2500 MHz. Wattmeters, test equipment,rf power meters, duplexers, filters and cavities, transmitters combiners

About digital modes - The digital modes provide a wonderful opportunity for those of us who would like to work on the HF bands but find CW too difficult and SSB phone prohibitive because of interference problems. The digital modes are easy to set up and get operating, require low power and a narrow band.

Recommended frequencies for digital modes - Active digital mode frequency list compiled by Jason Buchanan - N1SU

PSK63 - A super-fast PSK mode for RTTY Contesting, 100 wpm character transmission speed for contest exchanges and macro transmission versus RTTY at 60 wpm

Frequency Calibration for Weak Signal Work - Accurate calibration of your receiver and sound card is necessary for good results with the weak signal modes in use at LF. Modern receivers with master oscillators that are synthesized to provide all conversion frequencies greatly simplify the process. This article describes a method of making the necessary measurements and adjustments to an ICOM R75 receiver and a sound card, using the ARGO software

SB-220 / 200 Amplifier with Solid-State Transceivers - Using Solid-State Transceivers With Older Tube Amplifiers, some Hines and Kinks on the Heath SB-220/200 that can be useful in your application

Yaesu FL-2100Z Linear HF Amplifier Mods  ^updated - Two usefull modifications of the FL 2100

Kenwood ts-2000 and packet/digital mode - Using the TS-2000 for packet and digital modes. How to connect the Kenwodd TS2000 to TNC

Smith Chart Software - SimSmith is a highly interactive, real time Smith chart graphing program. Circuits are constructed using drag-n-drop. Load files can be imported from the EZNEC and CocoaNEC antenna simulation software and from the AIM4170 and miniVNApro antenna analyzers. Circuits and load files can be of any size. Key Features: SimSmith is one of the few Smith chart packages which models transmission line losses. SimSmith also allows the description of circuit elements using algebraic equations. SimSmith has only one screen and allows the screen to be resized to increase workspace or readability.

Phase 3D (AO-40) Decoder - This program demodulates the telemetry data signal transmitted by the AO-40 satellite (aka Phase III-D) using the PC sound card

Konfabulator - DX Cluster Priority listing - Freeware windows XP and MacOSX konfabulator widget dedicated to Amateur radio operators, is an easy interface to DX-Summit the ham-radio DX Cluster. DX cluster spots represents live ham radio communication connections, and are an invaluable resource for amateur radio operators. Users can choose Bands or operating modes like digital emissions, QRP IOTA and more. Spots are refreshed automatically and refresh rate can be set by users, with a minimum of 100 seconds.

LocCalc - Distance and directions calculation program using both Spheric, the perfect round earth model, and Vincenty's inverse ellipsoid algorithm, the WGS 84 earth model.

HamCalc - Add-in module to Microsoft Excel, contains a set of radio amateur relevant special functions: DistSphericLocator(Loc1; Loc2) Calculates the spheric earth model distance between two locators [km] DirSphericLocator(Loc1; Loc2) Calculates the spheric earth model direction from Loc1 to Loc2

MMvari - MMVARI is a multi-Mode SoundCard Ham (Amateur) Radio program for receiving and transmitting the RTTY-PSK-FSK-MFSK modes. The program was written to experiment with the efficiency of transmitting Japanese and East Asian languages (HL/BV/BY) using the VARICODE

QuikPSK - Supports both PSK31 and PSK63, sends and receives color thumbnail portraits by PSK63, displays 24 PSK63 channels simultaneously, and features semi-automatic mode selection between PSK63 and PSK31. Merely left-click on a PSK63 signal to copy, or right-click on a PSK31 signal to copy.

RigResident - RigResident is a small program for RIG control, which does allow to set and read data of connected tranceiver (frequency, mode etc). RigResident supports more than 70 TRX models from ICOM, KENWOOD, YAESU and Ten-Tec.

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

Radio and Scanner Modifications  ^pop - Scanner and radio mods taken from qrz ham radio cd rom