On Tue, Aug 7, 2018 at 8:42 AM, Dennis - WU6X <wu6x@...> wrote:
These are great except for NVIS, which should fall under #antennas. We need to keep Hashtags as general to a "topic" as possible, otherwise the list will grow exponentially making it more difficult to find an existing Hashtag to assign. Also, a search should list all related content, not just a single Message topic. It's easier to search through a list of search results rather than to do multiple searches for different Hashtags that one thinks may contain the desired content.
NVIS is a general topic that is about considerably more than antennas.
- Special Interest Groups
There is group activity dedicated to operating and testing NVIS regional communications, such as the Red Cross group operating up and down the coast every Saturday morning on 75/60/40 meters and then publishing a table of signal reports from various locations.
- Propagation studies, tools, awareness
There are special propagation tools to show current and historical ionospheric conditions relevant to NVIS. Choice of frequency for ionosphere conditions and more generally, time of day is quite specific to NVIS and different from DX operation.
- Distinct digital modes
Choice of digital HF mode is quite different for NVIS rather than those optimized for DX, due to the distinct fading modes of NVIS.
- Military and emergency programs
The FEMA SHARES program and the military interoperable exercises are about NVIS operation in a way that is much more than antennas.
- And yes, also, NVIS-specific antenna theory, construction, and deployment (which overlaps with #antennas)
Horizontally-polarized mobile antennas; height above ground - higher is not better beyond 1/4
λ, HF diversity and circular polarization
That said, I agree with your point that hashtags should be as general as possible---but not more so.
- Jef N5JEF