Re: NEC-LIST: What am I doing wrong and/or don't understand ?

Hello Doug (and others)...
 
> The range for
> "theta" is 0 to 180 deg., but you have it starting at -90.
> Also, since you are running a real ground, the range should
> be restricted to 0 (straight up) to 90 deg. (straight out
> horizontal).

The files I attached used the RP card for a default 3D far-field
pattern. The RP card's I used for Average Gain test was the
following:

RP 0 19 73 1001 -90.0 0.0 5.0 5.0

So I ran theta (because of ground) from -90 to 0 and Phi for
the full 360 degree circle. I do not think there is no difference
between running theta from -90 to 0 or from 0 to 90.

Furthermore I used 'perfect ground' for the average-gain test
whereas you used a somnec ground (14, .006). For as far as I
know to perform an AGT one should use free space of perfect
ground...

> I modified your RP statements, including
> changing XNDA to 1004 to get the average gain report, and
> ran them.

XNDA = 1004 ?, I consulted the Nec2 user manual but for the
'A' field I get the following:

A - (column 20) requests calculation of average power gain over
the region covered by field points.
  A = 0 no averaging.
  A = 1 average gain computed.
  A = 2 average gain computed; printing of gain at the field
  points used for averaging is suppressed. If NTH or NPH is
  equal to one, average gain will not be computed for any value
  of A since the area of the region covered by field points
  vanishes.

I am not aware of any usage for A=4. Maybe an undocumented
feature.. ?

When using 'your' RP card, I get two completely different AGT
results: 0.880918 for arie1 and 1.71072 for arie2

When I use the 'my' RP card I get two comparable results:
2.23278 for arie 1 and 2.24155 for arie2, saying both models
could be a bit doubtful, but saying nothing about (radiation)
efficiency.

The AGT including SomNec ground reports significant differences
because of the GN 2 usage. As does a 'normal' 3D plot !

Once you know the answer all seems so simple.......

Thanks for the feedback,
Arie.

-- 
(Please ignore the advertisements below)
+++ GMX - die erste Adresse für Mail, Message, More +++
Bis 31.1.: TopMail + Digicam für nur 29 EUR http://www.gmx.net/topmail
-- 
The NEC-List mailing list <nec-list_at_gweep.ca>
http://www.gweep.ca/mailman/listinfo.cgi/nec-list