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Dated 5Oct2008, mclapp posted a 4nec2 file for the (old) Antennas Direct DB-4:
http://www.frontiernet.net/~mclapp/Antennas/Computer Models

On 9Feb2009, d510d180 posted a parameterized 4nec2 file for the (old) DB-4 in the
"How to build a UHF Antenna" thread on that forum that shall remain nameless:
http://www.*************/avs-vb/showthread.php?p=15782728

Awhile back I was curious re Hi-VHF (only) performance and analyzed mclapp's DB4_300ohm.nec file,
which required adding and adjusting Rsrc for AGT=1.0. I just finished adding UHF analysis & uploaded:
http://imageevent.com/holl_ands/multibay/4bayrefl/db4refl

A-D DB4 has serious frequency roll-off on the lower UHF freqs as well as a high SWR on low-mid freqs.
Hi-VHF SWR is Excessive, with more Gain towards the REAR. These are all due to it being TOO SMALL:

Whisker Length=6.17-in, Tine Separation=1.2-in, Feedline Separation=1.8-in, Hop=1.0-in.
BowInner-Inner=7.85-in, BowInner-Outer=7.9-in, Two Reflectors: 12.7"x18.9", Sep=4-in.
 
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