Understanding Standing Wave Ratios SWR
- We worry a lot about Standing Wave Ratio (SWR) in amateur radio since SWR is one indication of how well our antenna system is working. Most HF transceivers and antenna tuners have built in SWR meters. SWR is a measure of a transceiverís output power verses the portion of that power reflected by the antenna system By Ken Larson KJ6RZ
- 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.
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
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
Antenna Selection Made Easy
- This page will help you answer important questions about antenna selection before you talk to a supplier. After reading this paper, you should be able to better determine the most important parameters you need to know for your antenna selection criteria.
New HF antenna HB9ABXpop
- A new, revolutionary design allows the construction of small HF antennas,
which provide the same efficiency as large antennas. This antenna can be built for all HF bands, from 10 to 80 m.
- 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
- FAX480 was developed to provide for relatively high resolution image transmission on HF, VHF, and UHF amateur radio bands. FAX480 was designed to bridge the gap between conventional slow scan television (SSTV) and conventional facsimile techniques.
A 80/40m Direct Conversion HF Receiver with DDS VFO
- Juha (OH2NLT) and Matti (OH7SV) have designed JUMA-RX1, an award winning 80/40m direct conversion HF receiver with highly accurate direct digital synthesis VFO. The receiver is very compact, because it constructed using surface mount components. No coils need to be wound to construct this receiver!