A model of a practical Ruthroff 1:4 balun
- The 1:4 balun is of particular interest because it underlies many other configurations, and understanding it helps towards understanding the other Ruthroff balun configurations.
Speedometers SWR Meters and Smith Charts
- Have wondered why a Smith chart has such strange grid lines. Believe it or not, there is a logical progression from Speedometers to Smith charts that will make the Smith grid crystal clear.
YO4PX Francisc Grunberg blog
- Articles about Amateur Radio, own writings and translations: history, DXpeditions, contesting and DXing ethics, Codes of Conduct, Suggestions for Pile-ups, Suggestions for Contesters, the most wanted DXCC entities.
GIGAVAC Ham Radio Relays
- Gigavac is a leading designer, manufacturer, and worldwide seller of contactors and high voltage relays using vacuum, gas filled, and high voltage reed relay technology. hv relay applications information with cross reference charts for kilovac / tyco, jennings, and crydom part numbers.
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).
Citizen Weather Observer Program
- A private-public partnership with three main goals to collect weather data contributed by citizens; to make these data available for weather services and homeland security; and to provide feedback to the data contributors so that they have the tools to check and improve their data quality
UK Radio Amateurs Annual CW Table
- The purpose of the table is to encourage CW activity on the HF bands and six metres. Each year participants start afresh and work as many DXCC entities on each of the ten bands as possible between 0000Z on 1st January and 2400Z on 31st December
- 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
Pro Key Set
- This small program helps you to edit the CW memories of your Icom 756Pro, 756Pro2, 746 or 746Pro rig. On startup it reads the current memory contents and displays it. You can edit the text and store the memories individually or all 4 together