Beskrivelse
Transmitting and Receiving Antennas Have Different Jobs to Do.
Although the fundamental characteristics of antennas apply to both transmission and reception, the requirements and priorities of receiving antennas can be vastly different from those of transmitting antennas. Receiving Antennas for the Radio Amateur focuses entirely on active and passive receiving antennas and their associated circuits. There are relatively few cases where a radio amateur cannot benefi t from a separate, well-designed receiving antenna or antenna system. On the low bands, including our new allocations at 630 and 2200 meters, heavy emphasis on the receiving end of these radio paths is essential for success.
The active antenna holds a prominent position in this book, as it offers good receiving performance while taking up minimal space. Recent developments in radio frequency (RF) semiconductors, especially low-noise RF operational amplifiers, have made a number of previously difficult-to-implement active antenna designs simple to build.
Table of Contents:
- Receiving Antennas are Different!
- Your Friend, the Decibel
- The Preamplifi er Problem
- The Amazing Disappearing Antenna
- The Receiving Antenna as a Signal Generator
- The Quest for Infi nite Power Gain
- The Role of the Resistor in the Receiving Antenna
- The Small Loop Antenna
- Achieving the Perfect Null
- You Can Make Accurate
- Field Strength Measurements
- The Aperiodic Loop
- The Q Factor
- The Beverage: In a Class of Its Own
- Dealing with Non-Reciprocal Propagation
- The Evolution of the eXOgon Antenna
- The Lowdown on LF
- The Random Wire
- Arrays and Beamforming Networks
- Powering Your Active Antenna
- Diversity Methods
- NVIS Receiving Antennas
- Receiving Antenna Projects and Accessories
- Materials and Construction Techniques
- Our Two New Bands
