Topband: Modeling verticals (fat, skinny, etc) on EZNEC

[Guy Olinger, K2AV]

> It would be nice if EZNEC had a type of source called "power", then 
> you
> could set it at 1 watt and not have to do the division.  But EZNEC
> doesn't.

EZNEC 4.0:

Options Menu: Power Level. Uncheck "Absolute V,I sources"

Initially set "Power level (watts)" to 1

Use a 1 meter long vertical RX antenna, with a meter's distance 
separating ground and the bottom of the RX antenna. Use a 1 ohm center 
load. Making the conductor diameter 1 cm will minimize any RX 
conductor related change in RX signal when conductor loss is changed

Run the rest of the model you describe with no R in the transmitting 
antenna perfect ground, and wire loss to "zero".

Click on "Load Data", note the power specified on the RX antenna 1 ohm 
load.

Divide 1 by that power. In Options menu, power level, change power 
level from 1 to the result of the division.

Rerun. The power on the RX antenna load should now be 1 watt.

Convert the model to real conductor loss, real ground, etc, and rerun.

Read power in RX antenna load, which will be an efficiency figure.

The exercise will need to be redone if dimensions, wire diameters, etc 
of the transmitting antenna are changed.


73, Guy.








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