Introduction to NVIS - Field Radio Podcast

Discussion in 'Videos and Podcasts' started by W7DBO, Apr 22, 2018.

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  1. W7DBO

    W7DBO Ham Member QRZ Page


    On this episode I discuss the NVIS or Near Vertical Incident Skywave propagation used to make contacts within a typical skip zone of long path HF. The training item discusses best practices for creating a family emergency communication plan.

    The Field Radio Podcast is dedicated to exploring the amateur radio hobby through the lens of getting you and your gear outdoors. Your host, John W7DBO, will explore what gear works best, how to deploy in the field, and most importantly how to have fun! The podcast will also explore what you can do with your gear once deployed. Including emergency communications, contesting, event support, and of course Field Day. Hope you join us on this adventure as we take Ham Radio outdoors! 73
  2. KK5JY

    KK5JY Ham Member QRZ Page

    I suspect that this is the future for "emcomm" in the US. It will be used for families or other communities to establish communication with each other in a cell-phone-down situation.

    Some of the content presented here is misleading. E.g., he asserts that only 40m through 80m are usable for NVIS, and that 160m is always attenuated by the D-layer. During our current low-SSN conditions, this isn't true. 160m can be very usable for NVIS at the low points of the sunspot cycles. Further, 160m can also be used for ground-wave and E-layer skip, unlike higher frequencies, making 160m capable of three different propagation modes within the skip zone, with a combination of verticals and low dipoles.

    Similarly, 40m is nearly unusable in low-SSN conditions, because the FoF2 doesn't climb nearly high enough to support high-angle 40m refraction in the F-layer. That is the situation we have nearly every day now. So people who try to use 40m for NVIS in 2018 are going to be very disappointed. They should be using 80m for daytime NVIS, as well as in the evening hours.

    It's good that people discuss high-angle contacts, because it is a very useful propagation mode, throughout the sunspot cycle. However, the content needs to be updated to reflect the differences in operation between the sunspot maxima and minima.
  3. KB4QAA

    KB4QAA XML Subscriber QRZ Page

    Long Path would be better replaced with Low Angle. Long Path relates to signal direction the opposite (around the world) from the shortest direction to a signal.

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