2m VHF antennas with high gain
- 2m SSB/CW-12.5 Ohm Yagis with extrem high gain and small bandwidth.
These Yagis were constructed as ultra-light, portable Yagis with extrem high gain. They have small bandwidth and are working from 144,0-144,8MHz with good SWR.
40-80 Half-Extended Double Zepp Antenna
- A dual-bander for 80M and 40m. An Extended Double Zepp (EDZ) is a 5/4 wavelength center-fed dipole.
This article will introduce the Half-Extended Double Zepp (HEDZ) which has characteristics that a lot of amateur radio operators should find quite interesting
Bromley Repeater Group - Gateway
- Website and Forums of The Bromley Repeater Group which has been formed to launch and maintain the new Kent repeater, GB3OK. Located in Orpington and with an ASL of 600 feet, it's predicted to provide coverage over a large area of London and South East England. Also on Echolink node 280040
Eliminate QRM from 6 meters band
- The circuit described below will substantially reduce or completely eliminate interference from almost any local source whilst leaving the wanted signal relatively unaffected, even though it may be on the same frequencey by TREVOR, G3ZYY
QSK for the TL-922 and SB-220 mods
- Beautifully constructed amplifiers. Unfortunately, are not suited for high speed T-R switching, a necessary attribute for operating AMTOR, QSK-CW, or SSB-VOX modes.
- Windows program for analyzing vertical antennas. This program shows the resistance and reactance to be expected looking into a cylindrical metallic tower over a perfect ground. It gives a useful approximation of the values to be expected in a real-world situation.
Elsie - Filter Design
- Filter design software. Elsie is an uncommon commercial-grade lumped-element ("L-C") electrical filter design and network analysis program, directed toward the engineer or technician involved in that line of work.
- Ham Log Mapping software freeware for Windows,
displays a map showing the amateur radio grid squares contacted and logged in using a third-party logging program by: Bertrand Zauhar, VE2ZAZ
Base-Station RF Power-Amplifier Biasing
- Power amplifiers used in base stations require biasing for proper RF performance. This article explains the two classes of biasing that are prevalent in the RF industry, analyzes their characteristics, and shows implementations with existing ICs.
Microphone connections by G4WPW
- Roy G4WPW has collected one of the most complete and interesting pages for microphone connections schemas and wiring. Includes Kenwood microphones schematics as well as Yaesu Icom Alinco Adonis Drake Heil JRC MFJ schematics
Filters and Ferrites in EMC
- This article is about the characteristics and use of various filters and ferrites for solving amateur radio electromagnetic compatibility problems involving breakthrough of amateur signals into domestic equipment such as television sets, video recorders stereo sytems etc.
An Inexpensive PL Tone Encoder
- If your local repeater has got you singing the PL tone blues, then read on. For less than $10, an inexpensive PL tone generator can be constructed that will bring new life into that old non-PL rig.