Discussion in 'Mobile Radio Systems' started by N0IOP, Oct 9, 2019.
http://www.sws.bom.gov.au/Images/HF Systems/Global HF/Ionospheric Map/WorldIMap0.gif
[QUOTE="N0IOP, post: 5222288, member: 899467] ...http://kv5r.com/ham-radio/nvis-army-fm-24-18/
The army seems to think it is practical enough to be useful, or at least thought that at one time. Or perhaps they were just experiencing groundwave propagation and, as you suggest, mischaracterized it as NVIS. But if you can get reliable ~300 mile comms, maybe it doesn't matter much.[/QUOTE]
Unless I am misreading your link it actually appears to match what K0BG et al are saying. Interpreting the chart a typical mobile setup would be up to 43 db lower compared to a NVIS dipole. In other words fuggitaboutit for practical use.
Don't get discouraged Steve. My real time testing between a vertical screwdriver and one mounted at 45deg showed an improvement of up to 20db with the 45deg tilt.on 80meters with stations at 50,100,200,300 miles.
So irregardless if it was Groundwave, Directwave,Spacewave,Skywave or Tidalwave it worked for me. I have called State wide traffic nets with this setup.
I was frequently asked what amp I was running.
And accused of lying when replying barefoot.
The changing characteristics are what we observe every year during our local Virginia QSO Party confirming NVIS for the longer instate radio circuits. When the band drops, it drops for all participants be they mobile, fixed or portable.
Because of the stored QSO data, VAQP is a great opportunity for analysis to see how well mobiles do on 80 and 40m... 80m being the hot one of late for obvious reasons. This Zed Thread inspired me to finally finish an article about one particular VAQP mobile operator that produces results... quite clearly via NVIS propagation.
Does anyone here REALLY know what NVIS is?
How about a 2 turn Small Transmitting loop in the bed of a pickup?
Of course... both in the amateur realm and professionally.
Alas, apparently not.
We tied the top of those military whips to a rope and pulled it down forming a semi-circle, for a valid reason