Wednesday, November 7, 2018

Ham Radio NVIS for Regional Communications

Hello Operators.
My buddy Gil F4WBY the Radio Prepper, just published amazing video on Regional Communications using NVIS or near vertical incidence skywave. Like myself, Gil uses amateur radio as a utility for communications and preparedness, so it’s a pleasure to share this video of his, with you. In this video, Gil sets up a low slung antenna about 8 feet or a few meters, horizontally above the ground. The results are impressive.

If you read the Ham Radio Off Grid with OH8STN, we discussed the three types of communications in terms of bands and range. Amongst them were Regional Communications. Gil is providing us a perfect example of Regional communications using NVIS, and a very modest antenna configuration. Let’s just go over those three types of communications, as mentioned in my blog post.
  • Tactical communications – in this example we’re talking about VHF/UHF Communications within a neighborhood, Communications on the Block, Communications on the farm, Communications at your cabin or retreat. We’re never talking about more than couple of miles or few kilometers. This is normally done between handheld radios, handheld to a mobile, handheld or mobile to a repeater, … In this example the handheld radio is king.
  • Regional communications – in this example we’re talking about City, County, or State wide coverage. Mr. Tacticool tells us repeaters are the regional comms primary domain, and he would be right if it weren’t for the grid down scenario. For regional Communications, we typically use principles for over the horizon Communications. Of course that could be a couple of VHF stations (6m-2m) with big towers and big yagi antennas pointed at one another. It can also be the upper end of HF (10m), but if we want reliable Regional Communications, we’re probably going to use HF on 40, 60 & 80m with an NVIS capable antenna configuration.
  • National & International communications – in this example we’re talking about coverage of an entire country or from one country to another. The only reliable means of national or International Communications using Ham Radio is HF Radio. HF radio is what you primarily see in my videos. Theoretically there is no limit on range of communications with HF radio, but there is the need for understanding bands, time of day they are useful, and antenna configuration for it to be reliable.
In terms of a grid down scenario in large population centers, near vertical incidence skywave becomes critical, where Communications infrastructure has failed. We’re going to use near vertical incidence skywave for communications beyond the the range of handheld radios, usually somewhere local, out to a few hundred miles/kilometers.
If it’s at all possible, please reach out to Gil to let him where you found his video.
73
Julian oh8stn

No comments:

Post a Comment