Topband: Loud and local antenna

[Telegrapher9 at aol.com]

Ollie and the gang, 

And the winner is....

The vertical antennas were modeled with 15 ohms of extra ground loss to 
account for NEC-2 not fully modeling ground losses. One 90-deg radial is run along 
the ground directly under the horizontal wire. The dipole is an inverted-vee 
at 65 feet, and 140 feet long. It is loaded with two 35 uH, Q = 300 coils. 


15 deg TOA:
DIPOLE           -8 dBi
90-deg Inv-L     -5 dBi 
135-deg Inv-L   -8 dBi

30 deg TOA:
DIPOLE           -3 dBi
90-deg Inv-L     -5 dBi 
135-deg Inv-L   -2 dBi

50 deg TOA:
DIPOLE           -0 dBi
90-deg Inv-L     -3 dBi 
135-deg Inv-L   -2 dBi

70 deg TOA:
DIPOLE           -2 dBi
90-deg Inv-L     -11 dBi 
135-deg Inv-L   -2 dBi

For your use it looks like a toss-up between the 135-deg Inv-L and the short 
dipole. For you use. For all around goodness I think the 135-deg Inv-L is the 
winner.

If you decide on an antenna I can send you accurate data on loading, 
matching, VSWR, etc. I'll also look into the inverted-U today. I have not done much 
modeling with these. If you look at the inverted-L's they are sideways U's. Like 
a vertical dipole with the ends bent to the horizontal. Due to being close 
the ground the bottom dipole wire suffers high ground loss. 

BTW, I'm finally springing for NEC-4 so that I can more accurately model 
radials in the ground. With NEC-2 I have to add some base loss and hope for the 
best.


    Dave WX7G