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|1/16/2004||ANTENNAS||Tape Measure Antenna
Designed for use when portability and operation on different frequencies are primary the considerations. The antenna is housed in a molded plastic housing holding two stainless steel tapes calibrated in meters, decimeters and centimeters. These tapes can be extended to the required length for a given frequency and locked in place. A permanent frequency-to-meters conversion chart is attached to the antenna housing. Each end of the tape is attached to a length of nylon line which acts as an insulator and a means for securing the antenna to structures of suitable height.
|1/15/2004||ANTENNAS||North America NVIS
North America NVIS Optimum Frequencies
|1/15/2004||ANTENNAS||Near-Real-Time F2-Layer Critical Frequency Map
Useful information for choosing appropriate band for NVIS antennas.
|1/12/2004||ANTENNAS||NVIS relative gain table
Summary of relative gain toward the zenith for field-expedient high frequency atennas (in dB).
|1/12/2004||ANTENNAS||NEAR-VERTICAL SKY-WAVE CONCEPT
NEAR-VERTICAL INCIDENCE SKY-WAVE PROPAGATION CONCEPT
|1/9/2004||ANTENNAS||An Elaborate inverted V for NVIS?
low_loss_inverted_v.jpg (JPEG Image, 507x760 pixels)
|1/9/2004||ANTENNAS||NVIS PowerPoint Presentation from Comm Academy 2003
NVIS PowerPoint Presentation from Comm Academy 2003
|1/9/2004||ANTENNAS||Near Vertical Incident Scattering Antenna
Near Vertical Incident Scattering Antenna
|Near Vertical Incidence Skywave HF radio wave techniques
NVIS Near Vertical Incidence Skywave HF radio wave techniques. Perfect for emergencies or to transmit and receive out to a 200 mile radius without a dead skip zone. A hilltop location or beam type antenna is not required. Vehicular operation is possible. We also dicsuss using low profile, invisible antennas and covert communication techniques.
AS-2259/GR HF Portable Antenna