Calculating radiation pattern changes.

Sirs,
In order to calculate radiation pattern changes of high gain omnidirectional
vertically polarised cellular antennas (9dBd at 902MHz) by nearby metal
structures or out-of-band antennas, I have the following questions:

1) I have been using AO6.0 and NW from Brian Beezley, K6STI for some time now.
Since such a vertically polarised antenna is not provided in the
K6STI-library, I scaled a 4 dipole array, which I am using on 2 meters to the
above mentioned frequency. Then I modelled the structure and ran it through
NW.
The 2m model provided an antenna lobe which wasn't awaited but which was
consistent with stations and reports received!

Can I trust the 902 MHz-results or am I running into the limits of AO-NW?
Did you model such a high gain vertical (colinear) antenna before?
Can you provide installation guidelines or do we need to trust the
manufacterer figures, recommendations?
Please state your experience.

2) Which commercial software packages do you recommend to perform this
calculus, what hardware is required?
The accuracy should be within 2 dB.
The AO-soft has a very easy and intuitive input format, do these packages also
provide such allowance and at what cost?

Thanks in advance for sending me your info.

Michel Spelier, ON7EH
Michel.Spelier_at_is.belgacom.be
Received on Wed Feb 28 1996 - 08:14:00 EST