Topband: 33', 50', 60' inverted "L" comparison assistance request

[Telegrapher9 at aol.com]

The Inverted-L and the T are pretty close in performance, if one considers 
less than a decibel to be close. In the case of the 50' x 83' Inverted-L, the T 
is better by about 0.7 dB at a TOA of 10 degrees. The T in this simulalation 
is 50' with a top wire of 120'. The radiation resistance of the T is lower by 
about 1 ohm. If the effective ground loss resistance is 10 ohms the Inverted-L 
and the T are equal in performance. That is, the lower radiation efficiency of 
the T nullifies the advantage it has in low angle radiation. 

The ground current distribution is a bit different too and this will affect 
things unless the ground is quite good. With the Inverted-L there is more 
ground current in the direction of the horizontal wire. With the T the ground 
current is symmetrical. For the antennas in this example the T will require more 
ground wire.

Given an equal length horizontal wire the ground losses will (I think) affect 
each antenna equally. If the T is shorted so that the top wire is 83' it 
should require the same amount of ground wire as the Inverted-L. Placing the 
loading coil at the top or at the base looks almost like a toss-up as far as signal 
strength goes. 

   Dave WX7G