QM7 7 elements 144 MHz Yagi-Uda Antenna
- The QM7 antenna is a simple 7 elements Yagi with 3.70 m boom length for the lower 144 MHz SSB/MGM band, used it mainly for Sporadic-E and MS contacts. It exhibits a forward gain of 11.35 dBd; i.e. 13.5 dB forward gain over the isotropic radiator, while the F/R is about 12.5 dB
- Whenever you choose a coax feedline, the frequency of operation is a very important consideration. Over the operating bandwidth of the coax the VSWR is low, typically 1.2:1 or better. Insertion loss is also an important parameter. It is usually specified in dB/foot and is a linear relationship.
Yagi Element Mounting Considerations
- One of the most important considerations when designing and building a Yagi antenna is the method used to attach the elements to a boom. This is true because the boom influences the electrical length of the elements. In this article JH Reisert explain with drawings techniques on mounting yagi antenna elements to a boom
- 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
WA4DSY 56KB RF Modem
- This is a prototype of the WA4DSY 56KB RF modem. It is intended for use on amateur packet radio networks. The modem generates RF in the 28 to 30 mhz range and requires and linear transverter to convert the signal to a UHF or microwave ham band
Islamic Republic of Iran Broadcasting
- Broadcasts national and international programs locally and to all world regions in over 30 languages on mediumwave FM, TV, RealAudio/TV and on shortwave.
In Touch Ministries
- Broadcasts Bible teachings in 15 languages to all world regions on local media such as mediumwave, TV and FM, via international shortwave radio and Internet radio and TV.
China Radio international
- The People's Republic of China External Service broadcasts featured programs, commentary and news via FM and shortwave to most of the world's regions using English, German and Spanish.
- One of several Colombian broadcasting networks heard on AM and FM and worldwide on 5076 kHz in the 60 meter band.