Brian-
Hard to say. You would be creating an "open sleeve" type antenna - which
would be detuning the dipole. How much is hard to say. My guess is that
you would have to adjust the length of the 40 dipole to compensate. Still,
I think the pattern would be unaffected; only the resonant frequency.
You would definitely have more problems with placing the 40 dipole
parallel to the quad elements. What Force12 has discovered and utilized
in their multiband beams is that to minimize interaction, you have to place
the lower frequency elements behind at least the driven element; and preferably
behind the reflector, of a parasitic array.
There are models of the 40-2CD including the loading coils and
capacity hats. Here's one:
CE
GW 1 4 131.5 0 840 131.5 72 840 .625
GW 2 4 131.5 72 840 131.5 116 840 .5625
GW 3 4 131.5 116 840 131.5 160 840 .5
GW 4 4 131.5 160 840 131.5 169 840 .375
GW 5 1 131.5 169 840 131.5 178 840 .375
GW 6 4 131.5 178 840 131.5 246 840 .25
GW 7 4 131.5 178 857.25 131.5 178 840 .094
GW 8 4 131.5 178 840 131.5 178 822.75 .094
GW 9 4 114.5 178 840 131.5 178 840 .094
GW 10 4 131.5 178 840 148.75 178 840 .094
GW 11 4 131.5 -.000007047 840 131.5 -72 840 .625
GW 12 4 131.5 -72 840 131.5 -116 840 .5625
GW 13 4 131.5 -116 840 131.5 -160 840 .5
GW 14 4 131.5 -160 840 131.5 -169 840 .375
GW 15 1 131.5 -169 840 131.5 -178 840 .375
GW 16 4 131.5 -178 840 131.5 -246 840 .25
GW 17 4 131.5 -178 857.25 131.5 -178 840 .094
GW 18 4 131.5 -178 840 131.5 -178 822.75 .094
GW 19 4 148.5 -178 840 131.5 -178 840 .094
GW 20 4 131.5 -178 840 114.25 -178 840 .094
GW 21 4 -131.5 0 840 -131.5 18 840 .6875
GW 22 4 -131.5 18 840 -131.5 72 840 .625
GW 23 4 -131.5 72 840 -131.5 116 840 .5625
GW 24 4 -131.5 116 840 -131.5 160 840 .5
GW 25 4 -131.5 160 840 -131.5 169 840 .375
GW 26 1 -131.5 169 840 -131.5 178 840 .375
GW 27 4 -131.5 178 840 -131.5 252 840 .25
GW 28 4 -131.5 178 857.25 -131.5 178 840 .094
GW 29 4 -131.5 178 840 -131.5 178 822.75 .094
GW 30 4 -114.25 178 840 -131.5 178 840 .094
GW 31 4 -131.5 178 840 -148.75 178 840 .094
GW 32 4 -131.5 .000007047 840 -131.5 -18 840 .6875
GW 33 4 -131.5 -18 840 -131.5 -72 840 .625
GW 34 4 -131.5 -72 840 -131.5 -116 840 .5625
GW 35 4 -131.5 -116 840 -131.5 -160 840 .5
GW 36 4 -131.5 -160 840 -131.5 -169 840 .375
GW 37 1 -131.5 -169 840 -131.5 -178 840 .375
GW 38 4 -131.5 -178 840 -131.5 -252 840 .25
GW 39 4 -131.5 -178 857.25 -131.5 -178 840 .094
GW 40 4 -131.5 -178 840 -131.5 -178 822.75 .094
GW 41 4 -148.75 -178 840 -131.5 -178 840 .094
GW 42 4 -131.5 -178 840 -114.25 -178 840 .094
GS 0 0 .02540
GE 1
GN 0 0 0 0 13 .005
EX 0 1 1 0 1 0
LD 0 5 1 1 3.53 .00001293 0
LD 0 15 1 1 3.53 .00001293 0
LD 0 26 1 1 3.53 .00001293 0
LD 0 37 1 1 3.53 .00001293 0
LD 5 1 1 4 2.4938E7
LD 5 2 1 4 2.4938E7
LD 5 3 1 4 2.4938E7
LD 5 4 1 4 2.4938E7
LD 5 5 1 1 2.4938E7
LD 5 6 1 4 2.4938E7
LD 5 7 1 4 2.4938E7
LD 5 8 1 4 2.4938E7
LD 5 9 1 4 2.4938E7
LD 5 10 1 4 2.4938E7
LD 5 11 1 4 2.4938E7
LD 5 12 1 4 2.4938E7
LD 5 13 1 4 2.4938E7
LD 5 14 1 4 2.4938E7
LD 5 15 1 1 2.4938E7
LD 5 16 1 4 2.4938E7
LD 5 17 1 4 2.4938E7
LD 5 18 1 4 2.4938E7
LD 5 19 1 4 2.4938E7
LD 5 20 1 4 2.4938E7
LD 5 21 1 4 2.4938E7
LD 5 22 1 4 2.4938E7
LD 5 23 1 4 2.4938E7
LD 5 24 1 4 2.4938E7
LD 5 25 1 4 2.4938E7
LD 5 26 1 1 2.4938E7
LD 5 27 1 4 2.4938E7
LD 5 28 1 4 2.4938E7
LD 5 29 1 4 2.4938E7
LD 5 30 1 4 2.4938E7
LD 5 31 1 4 2.4938E7
LD 5 32 1 4 2.4938E7
LD 5 33 1 4 2.4938E7
LD 5 34 1 4 2.4938E7
LD 5 35 1 4 2.4938E7
LD 5 36 1 4 2.4938E7
LD 5 37 1 1 2.4938E7
LD 5 38 1 4 2.4938E7
LD 5 39 1 4 2.4938E7
LD 5 40 1 4 2.4938E7
LD 5 41 1 4 2.4938E7
LD 5 42 1 4 2.4938E7
FR 0 1 0 0 7.1 1
RP 0 1 360 1000 65 0 1 1
RP 0 181 1 1000 -90 0 1 1
EN
*********** NEC-Win Basic ************
FR 0 1 0 0 7.1 .05
SOMNEC
As far as the files I sent you, here's a shot at a key:
CE - comment - ignore
GW - describes a wire/conductor as follows:
GW N S X1 Y1 Z1 X2 Y2 Z2 R
where N is wire number
S is number of segments
X,Y, and Z are endpoints
R is radius
all units in my files are inches (I think).
GS 0 0 .0254 specifies the units used in meters. .0254 meters = 1 inch.
(If you accept that everything is in inches, you can ignore this one).
GE 1 I think this means us a real earth plane under antenna
GN 0 0 0 0 13 .005 ground conductivity, permittivity parms
EX Ne Nw S1 S2 M P - excitation; Ne is number of excitation (0 unless more
than 1 excitation)
Nw wire number to drive
S1 S2 segment ends to drive
M P magnitude and phase
LD T W S1 S2 R X ? - loading; T is type; ignore
W is wire to load
S1 S2 is segment to load
R is resistance
X is reactance
examples: LD 5 1 1 4 2.4938E7 is specifying the resistance of an
element to be the same as 6061 aluminum.
LD 0 5 1 1 3.53 .00001293 0 is a 12.93 uH 3.52 series resistance
inductive load in wire 5, segment(s) 1 to 1 for loading the
40-2CD.
FR -frequency of run
RP - plot commands
EN - end of deck
I hope this info is enough to let you do some runs. If you have trouble,
tell me which file you want and I'll manually convert it to plain-text
for you...
-Tony, K1KP, fisher@hp-and2.an.hp.com
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