How the EZNEC model was developed to mimic the base loading, impedance matching and lossy characteristics of the CVAT autotransformer and a guide with table for use with the model.

Revised simulation of Miracle Whip mounted directly on transmitter case. Now includes an emulation of the autotransformer to provide impedance matching, base loading and a reasonable estimate of internal loss. Requires use of a lookup table for certain parameters.

Antenna Notes for MiracleWhip on Transmitter.ez. Copy to same folder so EZNEC can find it.

EZNEC vertical patterns of model “MiracleWhip on transmitter.ez” with lossy transformer that exhibits wide VSWR bandwidth. Only counterpoise is the transmitter body. Runs at 3.5, 7. 14, 28 MHz. Do these bear any resemblance to experience?

Revised to incorporate impedance match, base load and loss of autotransformer for more realistic simulation. Miracle Whip remote from transmitter with 1/4 wave for 20m vertical monopole added to create a shortened vertical dipole. To simulate a MW mounted on a pole with a resonant coax feedline using a common-mode choke at 16′6″ from the dipole feedpoint.

Antenna Notes for MiracleWhip+20m_monopole-vertical dipole.ez - copy to same folder.

MiracleWhip+20m_monopole-vertical dipole_elev.png
EZNEC vertical pattern for model “MiracleWhip+20m_monopole-vertical dipole.ez” as a shortened vertical dipole, compared to MW on transmitter alone. Indicates a 13dB (2 S units) improvement.

MiracleWhip+3-counterpoises_on_2nd_flr.ez
Miracle Whip remote from transmitter standing in the corner of a 2nd flr room with three 1/4 wave counterpoises (40, 20, 15m). The 20m c-p is a resonant coax feedline using a common-mode choke at 16′6″ from the Miracle Whip. The other two c-p are separate wires. EZNEC 5 Demo. Revised to include impedance matching, base loading and inherent loss of the CVAT autotransformer for a more realistic simulation.

Antenna Notes for MiracleWhip+3-counterpoises_on_2nd_flr.ez - Copy to same folder so EZNEC can find it.

EZNEC vertical pattern for model “MiracleWhip+3-counterpoises_on_2nd_flr.ez”. Shows a 13dB (2 S unit) gain over the bare MW on 40m.