On Saturday August 26 the Nanaimo Amateur Radio Association (NARA) will be conducting NVIS radio propagation tests.
Your club/group is invited to take part. If time permits please could you ask your members to participate.
Taking part in the NVIS tests does not require a huge commitment of time. The NARA club station VE7NA will monitor 3.745 MHz LSB during a four hour period. All you need to do is call in with a signal report and location.
So, what is NARA planning to do?
Date: August 26, (Saturday)
Times: 11 am to 3 pm (11:00 – 15:00) Pacific
Frequency: 3.745 MHz
Recommended power: 100 watts
Monitoring: VE7NA will monitor 3.745 MHz all through the above time period for callers. VE7NA will also monitor the Island Trunk System for coordination Calling: VE7NA will put out specific calls on the hour and the half hour looking for contacts
NVIS Propagation
NVIS or Near Vertical Incident Skywave is a mode of propagation which during daylight will give ranges on the lower frequency bands of around 300 km.
For NVIS propagation the idea is to radiate a signal vertically upwards towards the ionosphere as indicated in the diagram below.
The retuning signal typically gives coverage out to a few hundred km. Working DX is of course different because for working DX we want to radiate our signal towards the horizon.
In addition, because NVIS signals are essentially going straight up and straight down this mode of propagation can work well in mountainous areas. It is also worth noting that NVIS propagation can be especially important in an emergency situation during daylight.
NVIS Antennas
There is a lot of material available on NVIS propagation.
Almost any 80m antenna will work, but antennas designed specifically for NVIS will be horizontally polarized, relatively near to the ground and as long as possible. As an example, a half wave inverted V dipole with its middle at say 10m high will work for NVIS. A low quarter wavelength end fed antenna will also work. Vertical antennas push RF towards the horizon so are not ideal for NVIS working, but at longer ranges vertical antennas have been shown to work for NVIS.
Below is an excellent NVIS antenna, essentially a beam firing your RF straight upwards.
Please join us on August 26
No matter what antenna you have for 80m please get on the air and give VE7NA a signal report on August 26. VE7NA will be located just to the South of Nanaimo near Nanaimo airport.
The operator team at VE7NA will log all contacts and likely test a few antennas. Please bear in mind that for stations near Nanaimo, signals may be exchanged by ground wave propagation rather than NVIS but the local terrain could change this of course.
If these NVIS 80m daylight NVIS tests are successful NARA intends to write up a short report for the Radio Amateurs of Canada magazine, The Canadian Amateur.
We hope that you will be able to join in these tests.
Please contact the NARA Secretary, Devan VE7LSE (This email address is being protected from spambots. You need JavaScript enabled to view it.) if any further details are required.