NEC-LIST: Fw: Lambda/4 monopoles lamdba/4 apart

Hi

Some time ago I tried to model some of the old CCIR condifurations for MF Broadcast
arrays, and found I could not get the right radiation pattersn for Lamda/4 monopoles
 
I have now modelled a simple pair of Lambda/4 monopoles spaced lambda/4, and fed 90
 degrees apart in HFSS using perfect ground, and get a good cardiod pattern with a small
rear null.
 
I have modelled an almost identical confifration in NEC, and no matter how I tweak the
 detail (frequency, number of segments, number of wires in each monopole, wire
 diameter, EK command etc) I get a much worse pattern than using HFSS..
 
Can anyone tell me where I might be going wrong using NEC ?

CM Lambda/4 monopoles lambda/4 apart
CE
GS 0 0 1
GW 1 3 53.390 -0.000 0.000 53.390 -0.000 2.000 0.7500
GW 2 19 53.390 -0.000 2.000 53.390 -0.000 100.000 0.7500
GW 3 3 -53.390 -0.000 0.000 -53.390 -0.000 2.000 0.7500
GW 4 10 -53.390 -0.000 2.000 -53.390 -0.000 100.000 0.7500
GE 1
EK 0
GN 1
FR 0 1 0 0 0.77 1
EX 0 1 2 01 1.00 0.00
EX 0 3 2 01 0.00 1.00
RP 0 46 181 1001 0.000000 -180.000000 2.000000 2.000000
RP 1 25 73 1000 0.0 -180 1.0 5 1000
PT -1
EN

Phil Ede
Brighton, UK

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