Hi,

I am using 4nec2 and ICEPAC to design a 4-square inverted L. I think
the far field pattern, SWR, and area coverage are pretty good. I
believe most receivers can hear signals down to -120db fairly well. I
am modelling not only radials but also a ground system to reduce the
SWR and help with the lightning protection. I hacked this out of a
standard 4-square for 80 meters.

Any of the 4-square people out there who can offer additional pointers,
construction details, and other things I have not considered? I'm
finding trouble reducing the SWR from 2:1 down to 1:1

NOTE: Distance T is an arbitrary distance between the ground and a
planned wooden deck roof to help disguise the system. Distance D is an
arbitrarily small distance between the ground system and the dirt.

Thanks much!

The Eternal Squire


CM K6NA - 4-Element W1CF Phased-Vertical Array
CE converted with 4nec2 from AO to 4nec2 format on 22-apr-02
SY T = 9 ft
SY S = 17.3875 ft
SY K = T
SY M = 8.69375 ft
SY D = 0.1 ft
SY W = 8.69375 ft
GW 1 5 -S 0 T -S 0 T+W 1in
GW 2 5 0 -S T 0 -S T+W 1in
GW 3 5 0 S T 0 S T+W 1in
GW 4 5 S 0 T S 0 T+W 1in
GW 11 5 -S 0 T+W -S+W 0 T+W 1in
GW 22 5 0 -S T+W 0 -S+W T+W 1in
GW 33 5 0 S T+W 0 S-W T+W 1in
GW 44 5 S 0 T+W S-W 0 T+W 1in
GW 111 5 -S 0 K -S-M 0 K 0.25in
GW 112 5 -S 0 K -S+M 0 K 0.25in
GW 113 5 -S 0 K -S M K 0.25in
GW 114 5 -S 0 K -S -M K 0.25in
GW 211 5 S 0 K S-M 0 K 0.25in
GW 212 5 S 0 K S+M 0 K 0.25in
GW 213 5 S 0 K S M K 0.25in
GW 214 5 S 0 K S -M K 0.25in
GW 311 5 0 S K 0 S-M K 0.25in
GW 312 5 0 S K 0 S+M K 0.25in
GW 313 5 0 S K M S K 0.25in
GW 314 5 0 S K -M S K 0.25in
GW 411 5 0 -S K 0 -S-M K 0.25in
GW 412 5 0 -S K 0 -S+M K 0.25in
GW 413 5 0 -S K M -S K 0.25in
GW 414 5 0 -S K -M -S K 0.25in
GW 51 5 -S 0 0 -S 0 T 2in
GW 52 5 0 -S 0 0 -S T 2in
GW 53 5 0 S 0 0 S T 2in
GW 54 5 S 0 0 S 0 T 2in
GW 66 5 -S 0 D 0 0 D 0.25in
GW 67 5 0 0 D S 0 D 0.25in
GW 68 5 0 -S D 0 0 D 0.25in
GW 69 5 0 0 D 0 S D 0.25in
GW 70 5 -2S 0 D -S 0 D 0.25in
GW 71 5 S 0 D 2S 0 D 0.25in
GW 72 5 0 -2S D 0 S D 0.25in
GW 73 5 0 S D 0 2S D 0.25in
GW 80 5 -1S 0 D -1S -1S D 0.25in
GW 81 5 -1S 0 D -1S 1S D 0.25in
GW 82 5 1S 0 D 1S -1S D 0.25in
GW 83 5 1S 0 D 1S 1S D 0.25in
GE 1
SY I1 = 1
SY I23 = 1
SY I4 = 1
SY P1 = 0
SY P23 = -90
SY P4 = -180
EX 6 1 1 00 1.0 0.0
EX 6 2 1 00 .0 -1.0
EX 6 3 1 00 .0 -1.0
EX 6 4 1 00 -1.0 -.0
GN 0 0 0 0 13 0.002
'
FR 0 1 0 0 14.01
EN

'From the arrl antenna anthology, vol. 1.

don't worry about the swr, you need to build a phasing system that generates
the required feed currents and that can easily contain a network to bring
the output impedance to whatever you want to feed it with.

wrote in message
oups.com...
Hi,

I am using 4nec2 and ICEPAC to design a 4-square inverted L. I think
the far field pattern, SWR, and area coverage are pretty good. I
believe most receivers can hear signals down to -120db fairly well. I
am modelling not only radials but also a ground system to reduce the
SWR and help with the lightning protection. I hacked this out of a
standard 4-square for 80 meters.

Any of the 4-square people out there who can offer additional pointers,
construction details, and other things I have not considered? I'm
finding trouble reducing the SWR from 2:1 down to 1:1

NOTE: Distance T is an arbitrary distance between the ground and a
planned wooden deck roof to help disguise the system. Distance D is an
arbitrarily small distance between the ground system and the dirt.

Thanks much!

The Eternal Squire


CM K6NA - 4-Element W1CF Phased-Vertical Array
CE converted with 4nec2 from AO to 4nec2 format on 22-apr-02
SY T = 9 ft
SY S = 17.3875 ft
SY K = T
SY M = 8.69375 ft
SY D = 0.1 ft
SY W = 8.69375 ft
GW 1 5 -S 0 T -S 0 T+W 1in
GW 2 5 0 -S T 0 -S T+W 1in
GW 3 5 0 S T 0 S T+W 1in
GW 4 5 S 0 T S 0 T+W 1in
GW 11 5 -S 0 T+W -S+W 0 T+W 1in
GW 22 5 0 -S T+W 0 -S+W T+W 1in
GW 33 5 0 S T+W 0 S-W T+W 1in
GW 44 5 S 0 T+W S-W 0 T+W 1in
GW 111 5 -S 0 K -S-M 0 K 0.25in
GW 112 5 -S 0 K -S+M 0 K 0.25in
GW 113 5 -S 0 K -S M K 0.25in
GW 114 5 -S 0 K -S -M K 0.25in
GW 211 5 S 0 K S-M 0 K 0.25in
GW 212 5 S 0 K S+M 0 K 0.25in
GW 213 5 S 0 K S M K 0.25in
GW 214 5 S 0 K S -M K 0.25in
GW 311 5 0 S K 0 S-M K 0.25in
GW 312 5 0 S K 0 S+M K 0.25in
GW 313 5 0 S K M S K 0.25in
GW 314 5 0 S K -M S K 0.25in
GW 411 5 0 -S K 0 -S-M K 0.25in
GW 412 5 0 -S K 0 -S+M K 0.25in
GW 413 5 0 -S K M -S K 0.25in
GW 414 5 0 -S K -M -S K 0.25in
GW 51 5 -S 0 0 -S 0 T 2in
GW 52 5 0 -S 0 0 -S T 2in
GW 53 5 0 S 0 0 S T 2in
GW 54 5 S 0 0 S 0 T 2in
GW 66 5 -S 0 D 0 0 D 0.25in
GW 67 5 0 0 D S 0 D 0.25in
GW 68 5 0 -S D 0 0 D 0.25in
GW 69 5 0 0 D 0 S D 0.25in
GW 70 5 -2S 0 D -S 0 D 0.25in
GW 71 5 S 0 D 2S 0 D 0.25in
GW 72 5 0 -2S D 0 S D 0.25in
GW 73 5 0 S D 0 2S D 0.25in
GW 80 5 -1S 0 D -1S -1S D 0.25in
GW 81 5 -1S 0 D -1S 1S D 0.25in
GW 82 5 1S 0 D 1S -1S D 0.25in
GW 83 5 1S 0 D 1S 1S D 0.25in
GE 1
SY I1 = 1
SY I23 = 1
SY I4 = 1
SY P1 = 0
SY P23 = -90
SY P4 = -180
EX 6 1 1 00 1.0 0.0
EX 6 2 1 00 .0 -1.0
EX 6 3 1 00 .0 -1.0
EX 6 4 1 00 -1.0 -.0
GN 0 0 0 0 13 0.002
'
FR 0 1 0 0 14.01
EN

'From the arrl antenna anthology, vol. 1.

also, why bother with inverted L's? a full 1/4 wave vertical for 20m is
only about 15' tall, easily built from tubing or pipe and easily supported
even free standing.

wrote in message
oups.com...
Hi,

I am using 4nec2 and ICEPAC to design a 4-square inverted L. I think
the far field pattern, SWR, and area coverage are pretty good. I
believe most receivers can hear signals down to -120db fairly well. I
am modelling not only radials but also a ground system to reduce the
SWR and help with the lightning protection. I hacked this out of a
standard 4-square for 80 meters.

Any of the 4-square people out there who can offer additional pointers,
construction details, and other things I have not considered? I'm
finding trouble reducing the SWR from 2:1 down to 1:1

NOTE: Distance T is an arbitrary distance between the ground and a
planned wooden deck roof to help disguise the system. Distance D is an
arbitrarily small distance between the ground system and the dirt.

Thanks much!

The Eternal Squire


CM K6NA - 4-Element W1CF Phased-Vertical Array
CE converted with 4nec2 from AO to 4nec2 format on 22-apr-02
SY T = 9 ft
SY S = 17.3875 ft
SY K = T
SY M = 8.69375 ft
SY D = 0.1 ft
SY W = 8.69375 ft
GW 1 5 -S 0 T -S 0 T+W 1in
GW 2 5 0 -S T 0 -S T+W 1in
GW 3 5 0 S T 0 S T+W 1in
GW 4 5 S 0 T S 0 T+W 1in
GW 11 5 -S 0 T+W -S+W 0 T+W 1in
GW 22 5 0 -S T+W 0 -S+W T+W 1in
GW 33 5 0 S T+W 0 S-W T+W 1in
GW 44 5 S 0 T+W S-W 0 T+W 1in
GW 111 5 -S 0 K -S-M 0 K 0.25in
GW 112 5 -S 0 K -S+M 0 K 0.25in
GW 113 5 -S 0 K -S M K 0.25in
GW 114 5 -S 0 K -S -M K 0.25in
GW 211 5 S 0 K S-M 0 K 0.25in
GW 212 5 S 0 K S+M 0 K 0.25in
GW 213 5 S 0 K S M K 0.25in
GW 214 5 S 0 K S -M K 0.25in
GW 311 5 0 S K 0 S-M K 0.25in
GW 312 5 0 S K 0 S+M K 0.25in
GW 313 5 0 S K M S K 0.25in
GW 314 5 0 S K -M S K 0.25in
GW 411 5 0 -S K 0 -S-M K 0.25in
GW 412 5 0 -S K 0 -S+M K 0.25in
GW 413 5 0 -S K M -S K 0.25in
GW 414 5 0 -S K -M -S K 0.25in
GW 51 5 -S 0 0 -S 0 T 2in
GW 52 5 0 -S 0 0 -S T 2in
GW 53 5 0 S 0 0 S T 2in
GW 54 5 S 0 0 S 0 T 2in
GW 66 5 -S 0 D 0 0 D 0.25in
GW 67 5 0 0 D S 0 D 0.25in
GW 68 5 0 -S D 0 0 D 0.25in
GW 69 5 0 0 D 0 S D 0.25in
GW 70 5 -2S 0 D -S 0 D 0.25in
GW 71 5 S 0 D 2S 0 D 0.25in
GW 72 5 0 -2S D 0 S D 0.25in
GW 73 5 0 S D 0 2S D 0.25in
GW 80 5 -1S 0 D -1S -1S D 0.25in
GW 81 5 -1S 0 D -1S 1S D 0.25in
GW 82 5 1S 0 D 1S -1S D 0.25in
GW 83 5 1S 0 D 1S 1S D 0.25in
GE 1
SY I1 = 1
SY I23 = 1
SY I4 = 1
SY P1 = 0
SY P23 = -90
SY P4 = -180
EX 6 1 1 00 1.0 0.0
EX 6 2 1 00 .0 -1.0
EX 6 3 1 00 .0 -1.0
EX 6 4 1 00 -1.0 -.0
GN 0 0 0 0 13 0.002
'
FR 0 1 0 0 14.01
EN

'From the arrl antenna anthology, vol. 1.

Take a look at the far-field pattern and you'll see why I want it.
Also, it seems that inverted L's rather than verticals lower the
SWR from the thousands to something more sensible.

The Eternal Squire.

The feedpoint SWR will depend heavily on the type of feed system used.
The 4SqTL.EZ example model included with EZNEC, which uses one of the
all-transmission line feed systems described by "The Simplest Phased
Array Feed System - That Works", shows a 50-ohm SWR of 3.7 at the
feedpoint. Other feed systems are possible using this method, each of
which produces a different feedpoint impedance. The combination
transmission line - L network method described in Chapter 8 of the ARRL
Antenna book produces yet other feedpoint impedances, depending on the
transmission line Z0s which are chosen. There's no need to settle for a
feedpoint SWR in the thousands, and there's no need to alter your array
elements as a means of improving it.

If you use inverted-L elements for a four square array, it seems to me
you'd get a different elevation pattern in the various directions, and
that the azimuth pattern would be distorted by the directionality of the
elements. Have you modeled the full four element array, with the
currents phased as they would be for each of the four readily switchable
directions?

Roy Lewallen, W7EL

wrote:
Take a look at the far-field pattern and you'll see why I want it.
Also, it seems that inverted L's rather than verticals lower the
SWR from the thousands to something more sensible.

The Eternal Squire.

Roy,

Actually, I have modelled for a single direction, see my original post.
I am using 4nec2 for modelling the far field pattern. Would you be
interested in checking my work to see if anything better can be done?

The Eternal Squire

P.S: Do you have experience with 4-square arrays?

On 17 Sep 2005 20:14:27 -0700, wrote:
P.S: Do you have experience with 4-square arrays?
P.P.S. You must be kidding....

written in response to an almost identical query:
On Thu, 15 Sep 2005 16:06:10 -0700, Roy Lewallen
wrote:

wrote:
Roy,

I decided to go with a 20-meter 4 square. I wonder if any people have
experience with 4-squares that they can share with me. I have
considered some construction details give available materials, and I
have some questions.

I've built and used a few, for 40 meters.

P.P.P.S. You might want to visit the archives

wrote:
Roy,

Actually, I have modelled for a single direction, see my original post.
I am using 4nec2 for modelling the far field pattern. Would you be
interested in checking my work to see if anything better can be done?

The Eternal Squire

Sorry, I don't have the time just now.

P.S: Do you have experience with 4-square arrays?


Yes.