frequency counter

Making a half wave coax cable - How to make a half l or quarter l coax cable for a specific frequency

Eliminating TX RF Feedback Problems - Malfunction of transceivers due to stray RF pickup is a common problem, especially when using end-fed antennas, high-impedance feedlines, or a poor ground counterpoise

An End Fed Half Wave Antenna - This end fed type of antenna was marketted in the UK and is a useful system for the portable set-up. Being a half wave, no radials or counterpose wires are needed.

Quad antenna calculator  ^updated - To get the dimensions for your quad, all you have to do is type in the center frequency of the range where you talk, or the frequency you use most and then click the Calculate button.

Multi Band Antenna Traps - These devices are called Traps, but they are actually more like frequency sensitive switches. They are parallel resonant, high Q, tuned circuits which provide a very high impedance at their frequency of resonance.

The FD4 (FD3) Windom Antenna  ^pop - The 4-band Fritzel model FD4 is a special version of a Windom antenna. It is a half-wave long on the lowest frequency, and is fed from a coax cable through a transformer inserted in the wire at one-third from one end

Southern California Repeater and Remote Base Association - SCRRBA is a volunteer organization providing coordination of a number of heavily utilized amateur radio frequency bands in Southern California.

220 MHZ Spectrum Management Assn - Amateur radio spectrum management and frequency coordination entity for 219

T.A.S.M.A. - Amateur radio spectrum management and frequency coordination entity for 2-meters in southern california.

Comtechpst.com - High Power RF Amps - Comtech PST offers solid-state power amplifiers in frequency ranges from 1 MHz through 3.6 GHz, with output power levels ranging from 5 watts to over 30 kW

The Caltech Radio Frequency and Microwave Group - Develop microwave amplifiers and related products

Radio Frequency Systems - RFS is a global designer and manufacturer of cable and antenna systems plus active and passive RF conditioning modules, providing total-package solutions for wireless infrastructure.

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).

FDMDV - Digital Voice - FDMDV - Frequency Division Multiplex Digital Voice Digital Audio over HF SSB. FDMDV is the latest digital voice mode on HF - it caters to high quality digital voice under poor band conditions, in only 1100Hz bandwidth

IC7000BKT Icom IC-7000 CAT Control - CAT Control for Icom IC-7000 for windows. Management and synchronization of all memory bank, Management filters, volume, tones, DUP, DTCS, import export, audio recording and log frequency and signal,Auto CQ audio for repetitive calls

Scanning Tasmania - Frequency and scanning related information for scanning in and around Tasmania!

TubeCalc - Input (grid or cathode) and output (plate) tube resistances calculation according to its electrical characteristics, frequency, mechanical dimensions and working conditions.

glfer - glfer is a program for reception and transmission of QRSS/DFCW signals. It is composed of two main parts: the spectrogram window, where you can see the spectrum of the received signal vs. time the transmission functions, to emit cw characters at a slow but precisely controlled speed, using the QRSS (slow CW) or DFCW (Dual Frequency CW) modes

DTMF decoder - A very easy to use program to decode DTMF dial tones found on telephone lines with touch tone phones. The DTMF Decoder is also used for receiving data transmissions over the air in amateur radio frequency bands.

Ham Fan - A free small database program for Palm OS that allows you to log ham radio contacts. You can log the call sign, name, date, time and frequency of the contact.

IC746 control - IC-746 control It’s as simple as point and click. Left click will turn counter clockwise, and right click will turn clockwise.

HugeIcom - This is a very simple program which helps visually handicapped people to see the frequency and mode of the rig. Or maybe it's useful for demos, trade shows or similiar. It will work with any Icom except the IC-735.

RadioComm  ^pop - RadioComm can be used to program your Icom radio's memory, or to create nice radio-frequency spectra (see above) or to interface your radio to a huge database of frequencies.

Virtual Legacy Radio - Windows remote control for Yaesu or Icom. Displays the current transceiver settings frequency, mode, and others on the PC in an old-fashioned way that corresponds to the look of receivers in 70's. DX-Cluster Watch (DCW) is an application that automatically refreshes a web page with the dx-cluster content, parses spot lines from it, keeps a consolidated list and inserts the spots to VLR as frequency markers by OK1FIG

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