![NVIS: Near Vertical Incidence Skywave [ PodCast ]](https://qrznow.com/wp-content/uploads/2017/11/24180150.jpg)
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
M2 LEO-Pack Antenna System
AMSAT-NA and M2 Antenna Systems LEO-Pack AMSAT-NA Member-Only Special PricingThe 436CP16 and 2MCP8A are light weight, circularly polarized antennas op... Read more
Radiowavz Sentinel Expedition
“Hope (KM4IPF) talks about the Radiowavz Sentinel Expedition Hex Beam that she and her siblings have been using. They have come up with a few ti... Read more
Lesson 6.1 Antenna Basics
Antenna Basics “General Class Ham Radio instructional video, introduces Section 6.1 in the ARRL General Class License Manual. The section is ext... Read more
EF155SL – 21 MHz Mono band antenna by YU7EF
21 MHz Mono band antenna by YU7EF See More: Link Read more
OB12-6 12 Element Yagi 40-20-17-15-12-10m – Optibeam
Unique in the world: 6 bands – no traps – 1 feedline – no tuning – perfect performance The new version of the OB12-6,... Read more
Review
Ham radio HF Go-Kit QRP contacts FT-817 emcomm SHTF doomsday
Here is a video about my go-kit with my FT-817 and making some contacts QRP. Videos on almost all items can be seen on my channel. In this kit i have... Read more
5 Things Ruining Ham Radio | K6UDA Radio
” The funniest look at ham radio yet. For every 10 hams out there playing with everything ham radio, there’s some lonely guy sitting in hi... Read more
![YAESU FT- 891 First Test [ Video ]](https://qrznow.com/wp-content/uploads/2016/10/yaesu-ft891_asd-190x122.jpg)
YAESU FT- 891 First Test [ Video ]
FT-891 HF+50Mhz ALL MODE MOBILE TRANSCEIVER The FT-891 HF All Mode Mobile Transceiver once again continues Yaesu’s legacy for legendary receiver... Read more
Baofeng UV-5R Extreme Test! – Fire , Water , Freezer
Baofeng UV-5R Hello all! K5CLC here to share a really crazy and extreme field test I did on my year old Baofeng UV5R, to test its merit under the most... Read more
SPE 2K-FA Amplifier – ARRL Review
2 KW Solid State Fully Automatic Linear Amplifier The smallest in its class. Built-in Power supply and Automatic Antenna Tuner. Dimension: L 38, H 18.... Read more
Digital Modes
Packet Engine Pro HF Modem
Demonstration of the new HF 300b Packet Modem Read more
Goodbye FT8, Hello Olivia, The Magic HF Digital Mode
“So many people have started using FT-8 on HF, but they leave all the other modes to die off, like Olivia. Olivia isn’t new, but it offers... Read more
FT8 is exploding! – No Nonsense Amateur Radio Podcast #6
FT8 is exploding! 1#popular HamRadio digital mode In this episode of the No Nonsense Amateur Radio Podcast, Tom, KB5RF, and I explore... Read more
WSJT-X Version 2.5.1 has been Released
The WSJT-X development team has announced the general availability release of WSJT-X version 2.5.1. This release mainly contains i... Read more
Ultra Portable PSK31/RTTY Digital Modem Ham Radio HF Digital Modem
Digital Modem can encode/decode BPSK31/63, RTTY, QPSK and CWmodes without PC, specially for portable digital communication。With its internal high perf... Read more
Equipment
The Classic Astatic D-104 Microphone
Let’s take a quick look at the classic Astatic D-104 microphone! Read more
QCX-mini is coming soon!
QCX-mini is a response to quite a few comments on the new QCX+ kit, from people who want to take it out portable for SOTA operations and other po... Read more
Hambuilder HBR4HF 4 Band HF Transceiver
HBR4HF specification Heterodyne 10MHz Xtal filter exciter based on Hambuilder BritX exciter 300-25000Hz audio band pass active filter using NE5532 4 B... Read more
![Reviewing the Icom ID-52E 5W D-STAR Transceiver [ ICOM UK ]](https://qrznow.com/wp-content/uploads/2022/01/maxresdefault-1-90x60.jpg)
![Reviewing the Icom ID-52E 5W D-STAR Transceiver [ ICOM UK ]](https://qrznow.com/wp-content/uploads/2022/01/maxresdefault-1-180x120.jpg)
