From: little@nuts2u.enet.dec.com (nuts2u::little)
Subject: Re: spacing dimensions for quad antennas
Organization: Digital Equipment Corporation
Date: Mon, 23 Nov 1992 07:44:39 GMT
X-Posted-Via: NEWS-NOTES gateway (a hack!)

Here are 3 more designs that have better impedance results.  Again I
erred a little on F/B instead of gain, but the impedances are what you
wanted.  If I have time, I probably run 3 more with a longer boom (5
meters) and more emphasis on gain and pattern.  Also a quick note about the
format of the deck if you're not used to running NEC-2.  Only half of each
element is entered because quads are symetric and I simply reflect the
antenna to get the whole antenna analyzed.  I could probably reflect a
quarter of the antenna, but never bothered to make that optimization (rainy
day project this winter, :-) )  Each GW card defines a wire in a 3
dimensional space in the format:

GW Tag NS SX SY SZ EX EY EZ R

Where:
	Tag	- is a tag number used to identify wires in later cards.
	NS	- number of segments to divide the wire into.
	SX	- starting X coordinate in meters
	SY	- starting Y coordinate in meters
	SZ	- starting Z coordinate in meters
	EX	- ending X coordinate in meters
	EY	- ending Y coordinate in meters
	EZ	- ending Z coordinate in meters
	R	- wire radius in meters

So for each element there will be 3 GW cards.  The quad runs along the X
axis, so the X axis value gives you your element spacing.  The absolute
value of the starting Z coordinate of the first wire of each element gives
you 1/8 of the elements length.  

So for the first deck below, the elements are:

R	6.43 meters long
DE	6.05 meters long, 1.48 meters in front of the reflector
D1	5.77 meters long, 2.52 meters in front of the reflector
D2	5.68 meters long, 4.00 meters in front of the reflector

73 and good luck building these things.  From the quads I've built, I find
   I have to play a little with the DE element length to get the match
   right.
Todd
N9MWB

4 elements F/B ratio = 45 dB  Gain = 10 dBi  Impedance = 47 Ohms
===============================Begin Here=======================================
CM  4 element QUAD on a 4.000000m boom for 52.000000 Mhz 
CM  Generated on Sun Nov 22 22:09:41 1992
CE
GW 1 3 0.000000 0.000000 -0.803549 0.000000 0.803549 -0.803549 0.001885
GW 1 6 0.000000 0.803549 -0.803549 0.000000 0.803549 0.803549 0.001885
GW 1 3 0.000000 0.803549 0.803549 0.000000 0.000000 0.803549 0.001885
GW 2 3 1.477468 0.000000 -0.756706 1.477468 0.756706 -0.756706 0.001885
GW 2 6 1.477468 0.756706 -0.756706 1.477468 0.756706 0.756706 0.001885
GW 2 3 1.477468 0.756706 0.756706 1.477468 0.000000 0.756706 0.001885
GW 3 3 2.522532 0.000000 -0.720672 2.522532 0.720672 -0.720672 0.001885
GW 3 6 2.522532 0.720672 -0.720672 2.522532 0.720672 0.720672 0.001885
GW 3 3 2.522532 0.720672 0.720672 2.522532 0.000000 0.720672 0.001885
GW 4 3 4.000000 0.000000 -0.709862 4.000000 0.709862 -0.709862 0.001885
GW 4 6 4.000000 0.709862 -0.709862 4.000000 0.709862 0.709862 0.001885
GW 4 3 4.000000 0.709862 0.709862 4.000000 0.000000 0.709862 0.001885
GX  100  010
GE
FR  0    0    0    0    52.000000
EX  0    2    1    0    5.   0.
EX  0  102    1    0   -5.   0.
PT -1
PL  3   2    0    3
RP  0   1  181 1100   90.     0.      0.     1.0
EN
=================================End Here=======================================

5 elements F/B ratio = 70 dB  Gain = 10 dBi  Impedance = 50 Ohms
===============================Begin Here=======================================
CM  5 element QUAD on a 4.000000m boom for 52.000000 Mhz 
CM  Generated on Sun Nov 22 22:16:30 1992
CE
GW 1 3 0.000000 0.000000 -0.803549 0.000000 0.803549 -0.803549 0.001885
GW 1 6 0.000000 0.803549 -0.803549 0.000000 0.803549 0.803549 0.001885
GW 1 3 0.000000 0.803549 0.803549 0.000000 0.000000 0.803549 0.001885
GW 2 3 1.086481 0.000000 -0.756706 1.086481 0.756706 -0.756706 0.001885
GW 2 6 1.086481 0.756706 -0.756706 1.086481 0.756706 0.756706 0.001885
GW 2 3 1.086481 0.756706 0.756706 1.086481 0.000000 0.756706 0.001885
GW 3 3 2.000000 0.000000 -0.720672 2.000000 0.720672 -0.720672 0.001885
GW 3 6 2.000000 0.720672 -0.720672 2.000000 0.720672 0.720672 0.001885
GW 3 3 2.000000 0.720672 0.720672 2.000000 0.000000 0.720672 0.001885
GW 4 3 3.288269 0.000000 -0.721873 3.288269 0.721873 -0.721873 0.001885
GW 4 6 3.288269 0.721873 -0.721873 3.288269 0.721873 0.721873 0.001885
GW 4 3 3.288269 0.721873 0.721873 3.288269 0.000000 0.721873 0.001885
GW 5 3 3.754971 0.000000 -0.672627 3.754971 0.672627 -0.672627 0.001885
GW 5 6 3.754971 0.672627 -0.672627 3.754971 0.672627 0.672627 0.001885
GW 5 3 3.754971 0.672627 0.672627 3.754971 0.000000 0.672627 0.001885
GX  100  010
GE
FR  0    0    0    0    52.000000
EX  0    2    1    0    5.   0.
EX  0  102    1    0   -5.   0.
PT -1
PL  3   2    0    3
RP  0   1  181 1100   90.     0.      0.     1.0
EN
=================================End Here=======================================

6 elements F/B ratio = 50 dB  Gain = 10.2 dBi  Impedance = 48 Ohms
===============================Begin Here=======================================
CM  6 element QUAD on a 4.000000m boom for 52.000000 Mhz 
CM  Generated on Sun Nov 22 22:26:19 1992
CE
GW 1 3 0.000000 0.000000 -0.795982 0.000000 0.795982 -0.795982 0.001885
GW 1 6 0.000000 0.795982 -0.795982 0.000000 0.795982 0.795982 0.001885
GW 1 3 0.000000 0.795982 0.795982 0.000000 0.000000 0.795982 0.001885
GW 2 3 0.886481 0.000000 -0.756706 0.886481 0.756706 -0.756706 0.001885
GW 2 6 0.886481 0.756706 -0.756706 0.886481 0.756706 0.756706 0.001885
GW 2 3 0.886481 0.756706 0.756706 0.886481 0.000000 0.756706 0.001885
GW 3 3 1.600000 0.000000 -0.720672 1.600000 0.720672 -0.720672 0.001885
GW 3 6 1.600000 0.720672 -0.720672 1.600000 0.720672 0.720672 0.001885
GW 3 3 1.600000 0.720672 0.720672 1.600000 0.000000 0.720672 0.001885
GW 4 3 2.976538 0.000000 -0.727879 2.976538 0.727879 -0.727879 0.001885
GW 4 6 2.976538 0.727879 -0.727879 2.976538 0.727879 0.727879 0.001885
GW 4 3 2.976538 0.727879 0.727879 2.976538 0.000000 0.727879 0.001885
GW 5 3 3.055866 0.000000 -0.709862 3.055866 0.709862 -0.709862 0.001885
GW 5 6 3.055866 0.709862 -0.709862 3.055866 0.709862 0.709862 0.001885
GW 5 3 3.055866 0.709862 0.709862 3.055866 0.000000 0.709862 0.001885
GW 6 3 3.870279 0.000000 -0.633831 3.870279 0.633831 -0.633831 0.001885
GW 6 6 3.870279 0.633831 -0.633831 3.870279 0.633831 0.633831 0.001885
GW 6 3 3.870279 0.633831 0.633831 3.870279 0.000000 0.633831 0.001885
GX  100  010
GE
FR  0    0    0    0    52.000000
EX  0    2    1    0    5.   0.
EX  0  102    1    0   -5.   0.
PT -1
PL  3   2    0    3
RP  0   1  181 1100   90.     0.      0.     1.0
EN
=================================End Here=======================================
Newsgroups: rec.radio.amateur.misc