[SBE] NEC/4 Modeling

[Cris Alexander]

Okay, Paul. I understand.
 
I've done a ton of modeling over the years and in my experience, the far
field E-field differences between a modeled radial system and a perfect
ground plane are hardly worth all the trouble to model it all. We're talking
fractions of a dB at 1 km, and the base Z predictions are certainly in the
ballpark if not the infield. That being said, impedance prediction is
probably the weakest function of NEC/MN.
 
I can heartily endorse J.L.'s book and in fact the equations therein were
the basis for my own MN program (ACSModel).
 
______________________________
W.C. Alexander, CPBE, AMD, DRB
Crawford Broadcasting Company
Denver, CO
(303) 433-0104 Tel.
(303) 433-0905 Fax.
 
From: sbe-bounces at sbe.org [mailto:sbe-bounces at sbe.org] On Behalf Of Paul
Christensen
Sent: Thursday, May 17, 2012 2:30 PM
To: sbe member discussion mail list
Subject: Re: [SBE] NEC/4 Modeling
 
Hi Cris,
 
I'm trying to get accurate base Z results as well as surface wave field
strength predictions.  Within 4Nec2 is a fast radial wizard, but it does not
allow for changing ground placement, albeit the effect may be small.   In
any case, creating a buried system is easy enough through the geometry
builder utility.  The examples would be used to ensure that I've done the
job correctly.  
 
I've had this discussion with Arie Voors, 4Nec2's developer, as well as
Jerry Burke at LLNL.  The consensus is to create a modeled radial system for
best results.   Ben Dawson suggested J.L. Smith's examples, so I can start
there.
 
Regards,

Paul


===================================
Paul Christensen, Esq.
LAW OFFICE of PAUL B. CHRISTENSEN, P.A.
3749 Southern Hills
Jacksonville, Florida 32225
Office: (904) 379-7802
Facsimile: (904) 212-0050
Skype ID:  pc-immigration-lawyer
 <mailto:attorney at immigration-lawyer-us.com>
attorney at immigration-lawyer-us.com
 <http://www.immigration-lawyer-us.com/>
http://www.immigration-lawyer-us.com
Admitted to the Florida Bar #507334

This message and any attachments to it is intended solely for the
addressee(s) and may contain CONFIDENTIAL material. In no event will this
correspondence create an attorney-client agreement without an express,
written agreement between parties.  If you received this message in error,
please delete this message from your system and notify us immediately by
replying to  <mailto:attorney at immigration-lawyer-us.com>
attorney at immigration-lawyer-us.com or by calling us at
904-379-7802.  Any interception, review, retransmission, dissemination, or
other use thereof, or taking of action upon this information by persons or
entities other than the intended recipient(s) is strictly prohibited.
----- Original Message ----- 
From: Cris Alexander <mailto:crisa at crawfordbroadcasting.com>  
To: 'sbe member discussion mail list' <mailto:sbe at sbe.org>  
Sent: Thursday, May 17, 2012 4:12 PM
Subject: Re: [SBE] NEC/4 Modeling
 
Is this for AM broadcast? If so, set the environment for ground plane and
forget about trying to model a buried ground medium.
 
______________________________
W.C. Alexander, CPBE, AMD, DRB
Crawford Broadcasting Company
Denver, CO
(303) 433-0104 Tel.
(303) 433-0905 Fax.
 
From: sbe-bounces at sbe.org [mailto:sbe-bounces at sbe.org] On Behalf Of Paul
Christensen
Sent: Thursday, May 17, 2012 1:39 PM
To: sbe member discussion mail list
Subject: [SBE] NEC/4 Modeling
 
Looking to validate the buried radial parameters of a .NEC input file for a
non-phased, single monopole radiator.  I've been using the geometry builder
utility within 4Nec2 software, but I want to confirm radial depth results as
well as source/load parameters.  If anyone has an input file to share, it
would be very much appreciated.  I have J.L. Smith's book on order and will
use his examples as well.  Thanks!
 
Regards,
 
Paul
 
 
====================================
Paul Christensen, CPBE  CBNT  8-VSB  AMD
LAW OFFICE of P. B. CHRISTENSEN, P.A.
3749 Southern Hills,  Jacksonville, Florida 32225
Office: (904) 379-7802    Facsimile: (904) 212-0050
 <mailto:pchristensen at ieee.org> pchristensen at ieee.org
 

  _____  

_______________________________________________
The SBE Roundtable, SBE at sbe.org
To unsubscribe, go to http://seven.pairlist.net/mailman/options/sbe

http://seven.pairlist.net/mailman/listinfo/sbe
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://seven.pairlist.net/pipermail/sbe/attachments/20120517/d10fa1a2/attachment.html>