New NVIS Ideas

[VA3KOT John]

Hi Patrick, congratulations on getting yourself a NVIS antenna. After this weekend I will be out of town for the rest of June but if you are still interested in July send me an email (va3kot@gmail.com). In the meantime, try using WSPR (Weak Signal Propagation Reporter) to measure how far your signal goes. I recommend using QRP signal levels to make sure that only the high angle signals are reported. The lower angle signals from a NVIS antenna propagation pattern will be attenuated enough that they probably won't be picked up by any WSPR station. For example, a 5 watt signal will be attenuated down to 1.25 watts at the -6dB points on the propagation pattern and will not travel very far due to D-layer absorption. If you used 100 watts, your -6dB points will still be at 25 watts and could travel substantial distances masking the NVIS effect. The beauty of NVIS is it's ability to get strong signals into your local region irrespective of the terrain.

John, VA3KOT
Owen Sound.