I've been comparing the results for an antenna I modded [1] with the demo
version of EZNEC and 4NEC2. Although EZNEC warned that the segments were
a little long measurement with an MFJ analiser shows a good match with
the predicted results. Being naturally tight I thought I'd try one of the
other modeling programs 4NEC2 which allows more segments. However I noticed
a discrepancy of about 1dbi in the predictions and a different predicted
SWR. These differences remain even when the 4NEC2 model is constructed with
the same number of segments as the EZNEC version and both models using
no ground (free space).

As both models are offering results to 2 decimal places I would expect
to be able to trust them to 1dp. Am I just kidding myself that modeling is
this accurate (Ignoring all the real world variations)?



[1] 3 element UK VHF FM broadcast radio to 3 element 2M
--
Rod
M0DTG
"I could be wrong, I could be right"