Hi,

I do not know nobody who has included the building in the formula. It should
be interesting to get a report about it and I should be curious to get the
opinion of a telecom engineer or to see any radiation pattern with/without
building included.

Possible configurations are of course infinite. You can always replace any
object, car, house, etc, by a special configuration of selfs and caps.
Harder is to find the correct values... The only solution is to experiment
in the field with a meter as two house are never built the same way.

All depend first of the working frequency and then of the height of the
antenna above the object.
Over 1/6 lambda or so over/away from the house I am not sure that the object
will much influence your radiation pattern. Theoretically it does, in
practice this is another affair : could you hear this difference ?...
Then there is the problem of radiations transmitted by your home devices
too, from TV to boilder, TL and other old remote controller that could
surely more bothering that your "house" seen as a whole as they can transmit
RFI at some frequencies in ham bands.

Even with a dipole placed in inverted V the high point on top of the
chimney, the wire tilted at 45 deg like this,

!chimney
/ !
wire/ ! house wall

I know many OM that get excellent results, even in pile-ups (with patience)
as the antenna is somewhat directive and help a bit. They do not care about
the pattern, they practice, and they see that their "small antenna" perform
well. All the more when we know that this is the first third of the antenna
(close to the center feed point and thus from the chimney) that radiates and
much less the ends.

On the other side I know some OM that have erected their beam over
apple/cherry trees, they have never complained about any loss of power or
difficulties to work any entity.

If the problem exists well, its influence must be relativised.

Thierry, ON4SKY
http://www.astrosurf.com/lombry/menu-qsl.htm


"Jon Kåre Hellan" wrote in message
...
I've read a lot about modeling antennas and ground. But what about the
house? Dipole configurations might look like this.

----------------------------------+
| |
| |
\ W
\ / \
\ / \
--------| |
| |
---------------------------------------

Or this


-------------------------------------
|
|
W
/ \
/ \
| |
| |
--------------------------------------

Or even this

__ ^__
___/ | \___
___/ | \___
__/ W \__
__/ / \ \__
/ \
| |
| |
-----------------------------------

(ASCII art looks better in a monospace font)

The house probably makes a lot of difference to gain and pattern, and
also for other antenna types.

Modeling the house as part of ground might make sense, but there will
be lots of differences. Metal roof and sidings would turn the house
into a faraday cage. A wood frame house with no wiring and plumbing
may be almost like air.

Has anybody included buildings in their models, and have they checked
if this made the model more realistic. Any rule of thumb parameters?

Jon Kåre - LA4RT