"John Smith" wrote
Interesting. What URL did you get this data from, exactly?

The data for all but the DLM I generated myself in NEC. As I wrote in the
study, the DLM data came from the U.R.I. test report, of which I have a
printed copy.

And, I take it you are comparing a 1/4 wave DLM against a 1/4 reference?

The physical height of the 3.5 MHz DLM was not 1/4 of a free-space
wavelength. The test report states that it was only 33% as tall as that.
This is the reason that the other two short radiators in the study were set
to that height.

Why not compare a 1/2 DLM against a 1/4 wave reference, there physical
lengths are MUCH MORE similar?

Because the claim has been made that the standard DLM is the equivalent of
an unloaded, 1/4-wave monopole when both are used with the same r-f ground.
Investigating that was the purpose of the exercise.

RF