On 7/13/19 12:13 AM, PY1NB - Felipe Ceglia wrote:
Hi folks,
I am using 4nec2. It has a NEC card input format, and I can set variables,
which makes it great try changes on the antenna files.
I ended up finding a quick way to do it:
After setting the vertical wire:
Create a horizontal wire with the specified lenght, at ground level, it's
tip that will be connected to top wire must be coincident to the vertical
wire's bottom end.
Use a GM card to rotate it as desired and move it in z axis to vertical
wire's top end.
You can also just build the horizontal wire at the right Z height, and
do the rotation with a GM.
For what it's worth, I tend to use multiple GM cards to do moves, in
theory you can do the translations and rotations all in one shot, but in
practice, I wind up needing to change something.
I can later paste the NEC cards here if anyone would like to (I am typing
on the phone right now).
Thank you for your replies.
73,
Felipe CT7ANO, PY1NB
On Tue, 9 Jul 2019, 19:12 jimlux, <jimlux@earthlink.net> wrote:
On 7/9/19 9:58 AM, David Gilbert wrote:
Yes, but what he apparently wants to do is set the wire length while
horizontal and then rotate the wire to the desired angle, which avoids a
manual calculation of the new end point.
EZNEC+ has that capability built in to its NEC interface, but apparently
Felipe is using a different NEC application.
In 4nec2, you can do a
SY L = 10 ' length
SY ANG = 0 ' direction
GW {stuff} L*COS(ANG), L*SIN(ANG),H,Radius
But if you're running bare NEC then GM cards are how you'd do it.
I either use 4nec2, or python that builds a NEC deck. More of the latter
recently.
If you want to know about dielectric losses, effective height, and
feedpoint Z for short dipoles on the lunar surface, let me know.
Or the pattern when a thin wire antenna is bent by the spacecraft
rotatational acceleration - use the python to calculate the shape of the
wire, generate a stack of GW cards, run the model. Who cares if the NEC
deck is several hundred lines long.
(I think that in some cases, one might be able to use the catenary card
from NEC4 for this)
73,
Dave AB7E
On 7/9/2019 9:23 AM, Wes Attaway (N5WA) wrote:
It seems like you could just give the far end a new coordinate in the
desired direction and leave the other end connected to the vertical wire
end.
-------------------
Wes Attaway (N5WA)
(318) 393-3289 - Shreveport, LA
Computer/Cellphone Forensics
AttawayForensics.com
-------------------
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of
PY1NB
- Felipe Ceglia
Sent: Tuesday, July 09, 2019 10:29 AM
To: Tower and HF antenna construction topics.
Subject: [TowerTalk] NEC rotate wire
Hello,
When modeling an inverted L (tag 1 is the vertical part, tag 2 is the
horizontal), is there a quick way or trick to rotate the horizontal wire
(tag 2) and keep it connected to the vertical wire (tag 1)?
When I try to rotate it using the move/copy (GM) it gets away from the
vertical wire.
Thanks,
Felipe CT7ANO, PY1NB
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