TopBand: More on vertical vs dipole

[W2pm@aol.com]

In a message dated 97-10-20 02:01:31 EDT, gsmith.rdi@reutech.co.za writes:

<< I've been wondering whether it's possible that at certain times it's just
 necessary to have high angle radiation,  irrespective of the ground losses
 in or just outside the near field.  Is it possible that there is a vestige
 of E layer remaining all through the night, which, if the takeoff angle is
 too low, just reflects all the RF back to ground prematurely?  If that were
 the case, higher angle radiation would be refracted instead of reflected at
 this layer, with it ending up going in  the right direction for low angle
 reflection off the higher F layer. >>

I dont think the theories regarding takeoff angle are any different for the
TOP band - what I do think, tho, is Signal to Noise is THE MAJOR factor in
top band performance and there are many factors which go into any one
station's S/N ratio.   This, in my opinion, also explains the phenomena of
"unbalanced propogation" sometimes explained with elaborate theories of
trans-polar shifts in polarization, etc.

A beverage does'nt guarantee the best S/N ratio at all times - and the many
vagaries of the particular installation and feed system, as we have seen
recited here in recent threads can drastically affect a travelling wave
antenna's performance.  And, I suspect that a directional horizontal antenna
even of modest gain would outperform most practical beverages in its favored
direction. 

At amateur radio power levels of 1500 watts or so this is not nearly enough
power to to predict and establish  80 - 90% communications reliabilty over a
long distance path unless the station has exceptionally high performance
antenna systems installed under careful, scientific conditions which can be
accurately measured and assessed. 

Hell - thats what makes ham radio so much fun ...

73 Pete, W2PM

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