Anonymous ID: 1afa65 Dec. 25, 2021, 4:33 p.m. No.15254924   🗄️.is đź”—kun   >>5016

>>15254787

What type of comms covers an entire region on just a few watts? The source appears to come from directly overhead.

 

HF particularly between 2 - 10 Mhz, but especially 80 meters (~3.5 Mhz at night) and 40 meters (~7 Mhz daytime).

 

NVIS Near Vertical Incident Skywave. A horizontal wire a few feet off the ground (vs high in the air). The ionosphere reflects these frequencies. It's why lights are on the ceiling…

 

Why does the military use NVIS? Many advantages.

 

HF is long range…low angle skip is intercontinental…vertical skip is local/regional without foliage, terrain, buildings in the way…very low power…a few watts usually. Very hard to locate…signals are strongest overhead.

 

Don't believe me. It's why disaster relief programs immediately set up NVIS wires and humanitarian ops in remote areas do the same. Nothing new to ex-mil types or hams (who set up those emcomms) but maybe a new way to think about beyond-line-of-sight comms if the nets go down.

 

HF NVIS something to remember.

Anonymous ID: 1afa65 Dec. 25, 2021, 4:54 p.m. No.15255016   🗄️.is đź”—kun   >>5234

>>15254924

Time stamp on this 17:17. Surely a coincidence. Shows folks how easy…and effective an NVIS rig can be.

 

This is not just for military type scenarios. Anywhere reliable infrastructure is unavailable (to you) then you are well served to know your options.

 

HF NVIS something to remember.