Topband: NVIS Antenna

[sawyered at earthlink.net]

I was reminded of my interest in re-installing a low 160M antenna to
supplement by 2 el vertical phased array.  And since there was no where to
go this weekend and no College Hoops to watch, I thought, hey, I could get
something up and play around with it in the Spring Stew.  And that what I
did.

 

I put up a 160M full size inverted vee.  Top at about 55ft and ends at
around 15 feet.  Just high enough to decouple some of the ground losses but
other than that, straight up radiation for the most part.

 

I compared that to my 2 element T top vertical phased array that is half
wave spaced and fed in phase or 180 out of phase for an E/W or N/S pattern.


 

At about 2 hours before sunset I started tuning around and listening to
stations.  Understand from my location in Vermont there is literally no one
on within 100 miles of me almost all the time.  Unless W1SJ or K2LE are on
(SJ is 40 miles and LE is 80 miles).  I was interested to hear that until
about 30 mins before sunset - NONE of the signals we better on the NVIS inv
vee - in fact virtually all were down by 5 - 15db.  Then around that time I
started to notice that the 200 mile out stations  and as well the closer
stations started being equal on the NVIS and a few louder by maybe 5dB.
Then from Sunset for a good hour or more, MOST of the up to 200 mile out
stations were 5 - 15dB louder on the NVIS inverted vee.

 

Propagation is fascinating.  It's a keeper to have in the arsenal for the
selected need of 200 - 250 miles out from an hour before to maybe 1 - 2
hours after sunset on 160M.

 

Comments welcome.

 

73

 

Ed  N1UR