Ontario NVIS Event October 16th, 2016

Ontario NVIS Event October 16th

We invite all hams for a  southern Ontario regional NVIS communications event on October 16th from 1-4 PM EDT.

The goal of the event is to make contacts and talk to other operators using NVIS techniques. No restrictions on operation, just get on the air and operate with your best NVIS antenna.
Bands of interest are 40, 60, and 80, depending on conditions. Suggested frequencies for

SSB are 3.700-750, 5.375, and 7.060-070.

CW, 3.550, 5.3465, and 7.030.
We suggest this identifier when calling to make it easier to identify the participants: CQ NVIS Ontario “call sign”.
Ham operators across the province in many different clubs have expressed interest and hope you will join us on the air.

Participating clubs are :

Hamilton
Peel
Niagara
Kitchener
Kingston
York Region

In order to provide reliable communications with the 200 mile band the NVIS antenna is best to radiate between 70 to 80 degrees. A vertical has a low angle of radiation causing a bounce off the ionosphere that allows dx operation and is not appropriate for NVIS operation. We want to hit the F layer at the sweet spot of 70 degrees. This can be achieved by the use of dipoles at a low height. The common antenna height is 16 feet.

nvis-radiation-angle

The most reliable frequencies for NVIS communications are between 1.8 MHz and 8 MHz. Common bands used in amateur radio at are 3.5 MHz at night and 7 MHz during daylight, with experimental use of 5 MHz (60-meter) frequencies. Military NVIS communications mostly take place on 2-4 MHz at night and on 5-7 MHz during daylight.

Here are some simple antennas that can be easily made and deployed

http://arrl-ohio.org/SEC/nvis/NVIS%20-%20DX%20Engineering.pdf

I built this one

http://www.marc.on.ca/marc/ares/documents/NVIS_2040-80_20antenna.pdf

This is the AS-2559 DIY clone that I built but the leg lengths are not for 80m and 40m but with an antenna tuner it covers 80m-60m-40m easily. I use a 16 foot painter pole as the center support.

nvis_antenna

Another trick to increase the antenna take off angle towards 70 degrees is to use a mobile antenna and angle it accordingly

nvismobile

The last SET exercise proved the NVIS antenna to be useful with contacts made with the NCS (however they had the wrong antenna in place to be really effective). I did make contacts into Indianapolis, buffalo, Windsor with this antenna using 50 watts with 5-7 to 5-9 signal reports.

This has been a proven antenna design for many years with different variants and the simplest format can also be the inverted V dipole which could be a great antenna to use for the ONTARS or POWWOW nets.

NVIS is about radiation angle not so much as the antenna type.

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