80 Meter NVIS Antenna Project
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- Опубликовано: 2 июн 2024
- In an effort to create a more stable comms setup with my local club I've begun experimenting with Near-Vertical Incidence Skywave (NVIS) antenna systems. This is my first deep dive into NVIS antennas and I wanted a very short antenna that nearly any club member would be able to deploy. This electrically shortened antenna is only 44 feet long!
Special thanks to Martin E Meserve K7MEM and his fantastic website at www.k7mem.com. It’s worth a look!
The coil inductor calculator I used is at www.daycounter.com/Calculators/Air-Core-Inductor-Calculator.html, but there are several good ones online.
This project cost me about $35 and an hour or so of work. It worked well in initial testing during the daytime with a friend about 15 miles south west of my QTH. Our club will be doing more NVIS testing soon.
You make a valid point. I’ll try and include both in future videos. I appreciate the suggestion.
? I see the Calculator for inductance, how do you know how much inductance you are looking for , or targeting to build .
The K7MEM site will calculate needed inductance based on the length of antenna you're aiming to build. If you then take that inductance number, you can use the inductance calculator to get your turn count based on the diameter of your coil form.
I hope im explaing this in a way that makes sense.
I read somewhere that the high q is a result of using small gauge wire, and thicker wire has higher a. Would this work for close comms less than 10 miles away?
This should work well out to about 300 miles or so. You may be right about the thin wire and high Q.
Please use the Metric System. There are 206 countries around the world. Liberia uses the Imperial system. The United States has been changing to the metric system for years.
The rest has already evolved.