Sometimes the best direction to send your signal is straight up!
Near vertical incidence skywave, or NVIS, is a skywave radio-wave propagation path that provides usable signals in the range between groundwave and conventional skywave distances—usually 30–400 miles (50–650 km). It is used for military and paramilitary communications, broadcasting,[1] especially in the tropics, and by radio amateurs. The radio waves travel near-vertically upwards into the ionosphere, where they are refracted back down and can be received within a circular region up to 650 km from the transmitter.[2] If the frequency is too high (that is, above the critical frequency of the ionospheric F layer), refraction fails to occur and if it is too low, absorption in the ionospheric D layer may reduce the signal strength.
There is no fundamental difference between NVIS and conventional skywave propagation; the practical distinction arises solely from different desirable radiation patterns of the antennas (near vertical for NVIS, near horizontal for conventional long-range skywave propagation).
Antenna
YouLoop HF loop antenna
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Topband: Webinar – Waller Flag RX Antenna 101 – How to Construct a WF
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MAX6 -Antenna Analyzers
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Review
3. LDMOS HF AMPLIFIER 100W INPUT 2400W OUTPUT BLF188XR 2 PCS 1.8-54 MHZ
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Digital Modes
New “Pre-Release” Version of WSJT-X Includes FT8 Changes
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Video Demonstrates Digital Voice Plus Video “Teleconferencing” Scheme for HF
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Second Public Test of FT8 DXpedition Mode Demonstrates High Contact Rates Possible
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Equipment
Ameritron ALS-1306 AMPLIFIER, HF+6M, SOLID STATE, 1200 W PEP, 220 VAC
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Hambuilder HBR4HF 4 Band HF Transceiver
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Compact Power Supply for Elecraft Radios
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How to Build A 130 Watt Dummy Load for HF Ham Radio
In this video I go through the building of a paint can dummy load that a ham radio operator may require for testing and tu... Read more
PRE-RELEASE INFORMATION – IC 9700 [ ENGLISH ]
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