[Elecraft] “ELECRAFT NVIS field day”

David Herring david.n5dch at gmail.com
Fri Dec 17 19:20:07 EST 2021


It is absolutely true that antennas intended for NVIS use do not have to be hung low.  But they CAN be.  And there are instances where doing so can be desirable.

When I lived in Hawaii, we used NVIS for reliable statewide HF communications to very good effect.  When I hung my dipole up about 30 feet or so, I would frequently get calls from hams in Japan, Oceana, mainland US, Canada and elsewhere. Ordinarily that would be nice, but when one is specifically focused on local comms, that can get to be a problem. When I hung my NVIS dipole down around 10 feet, I still got excellent statewide communications but no longer got calls from afar.

So I kept my dipole low for local, and erected a vertical for DX.  Both worked perfectly for their intended use.

In Hawaii, 40 meters worked great for NVIS probably 11 out of 12 months a year. Someone else who knows can comment, but I got the impression that 40 meters almost never works for NVIS in the mainland US.  If this is true, an Elecraft NVIS field day might be limited to those who either have room for an 80 meter dipole, or who can devise some other kind of 80 meter antenna that can radiate up.

73,
Dave - N5DCH




> On Dec 17, 2021, at 11:05 AM, Julia Tuttle <julia at juliatuttle.net> wrote:
> 
> Wait, why would people think verticals are good for NVIS? Isn't a
> vertical's radiation pattern pretty much "sideways but not up", and NVIS'
> desired radiation pattern "up but not sideways"?
> 
> On Fri, Dec 17, 2021, 12:54 Jim Brown <jim at audiosystemsgroup.com <mailto:jim at audiosystemsgroup.com>> wrote:
> 
>> On 12/17/2021 6:12 AM, Greg Herman wrote:
>>> What if there was the annual event called the The Elecraft
>>> NVIS field day?
>> 
>> There is a major myth regarding NVIS that antennas must be low. This is
>> totally false. The facts are that vertical antennas are terrible for
>> NVIS, and that horizontal antennas work better up to nearly one-half
>> wavelength above ground. This study ran in National Contest Journal
>> several years ago.
>> 
>> http://k9yc.com/AntennaPlanning.pdf
>> 
>> 73, Jim K9YC
>> 
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