How close will nvis work?

[338_MtRushmore]

I have a buddy that is wanting to get into radio, but us communicating is a major reason for him. We are only 16 miles apart with a mountain between us. I feel like this is a stupid question, but it will take a lot of work to set us up to try.

 

[543_Dallas]

I have a buddy that is wanting to get into radio, but us communicating is a major reason for him. We are only 16 miles apart with a mountain between us. I feel like this is a stupid question, but it will take a lot of work to set us up to try.

There's a guy about 8 miles from me that I hear very well on 75 and 40. A friend used to live 4 miles away and we talked on 75m frequently. All of us have dipoles in the 30 to 40 ft range. It will work but there will always be times that it doesn't work.

 

[Mudfoot]

I talk almost daily to my friend on 40 meters. He lives around 10 crow miles. In the evening, when band goes long, it is a challenge. We switch back and forth on 80, too. Later in evening, we have to use 10 meters.

 

[338_MtRushmore]

I talk almost daily to my friend on 40 meters. He lives around 10 crow miles. In the evening, when band goes long, it is a challenge. We switch back and forth on 80, too. Later in evening, we have to use 10 meters.

This is actually very helpful, thanks.

 

[338_MtRushmore]

There's a guy about 8 miles from me that I hear very well on 75 and 40. A friend used to live 4 miles away and we talked on 75m frequently. All of us have dipoles in the 30 to 40 ft range. It will work but there will always be times that it doesn't work.

How does differentiate between ground wave and nvis?

 

[Dr T]

I am using NVIS with a 40,20,10 meter dipole on my privacy fence. The antenna is about 5 feet off the ground at the apex. I work people from 10 - 1000 miles away quite easily. I have also been able to work Alaska, Hawaii & Japan when the conditions are favorable. Experiment. The antennas don't cost much money and give great satisfaction when you get them right.

 

[Road Squawker]

there is no NVIS @ 10 and 20 meters, and very little @ 40.

 

[N0NB]

there is no NVIS @ 10 and 20 meters, and very little @ 40.

At higher solar flux values NVIS works on 40 quite well. It all depends on the value of the Critical Frequency.

To answer the OP's question, NVIS will probably be the most reliable between the two of you on 75/80m with antennas at about the 25-50 foot range at the apex and sloping down to anything above 15 feet at the ends. In all but the deepest days of winter depending on your latitude and the solar flux values, you'll have almost 100% reliable communications.

BTW, back in the day we just said we were using "cloud warmers" until the military NVIS term entered the vocabulary in the early '90s or thereabouts.