Ken:
With a short attention span, I'm not sure I understand the tree option you
mention, but if you can run one leg away from the wall, at near a right
angle, then put 2,3, 4 or more wires on the wall and call that your
counterpoise. Feed the wire against that. Picture a ground plane turned on
its side with the driven element running horizontal. That will get most of
the field away from the bricks.
--
Crazy George
Remove NO and SPAM from return address
"Ken Bessler" wrote in message
news

"Roy Lewallen" wrote in message
...
Hm, woops. My guess that they wouldn't be lossy was based on the
assumption that they don't contain much water. In light of what George
has said, I retract my guess. Putting your antenna close to anything
containing water is bad news from a loss standpoint, as George says.
Roy Lewallen, W7EL
Crazy George wrote:
Ken:
I've not run HF measurements on bricks, but I can tell you that a
brick
wall
is extremely lossy at 1 GHz and above, by measurement. Their water
(dielectric constant = 80) content is relatively high unless recently
baked
and sealed, and depending on the particular clay they were fired from,
they
are somewhat conductive. So, placing your antenna close is like
putting
it
next to a high dielectric RF absorber. Not a good choice.
--
Crazy George
Well, that expains the wide bandwidth between the 2:1 swr points
(1490 khz)......
Still, I am VERY limited as to my options - I rent here - so this
antenna is it or else I go with a Superantennas MP1 stuck out
the window. While the MP1 is a superb performer for it's size,
I don't think it could do any better than what I've got. Then there
is the fact that I'd have to have the window open to make room
for the MP1 - not a good idea in january in colorado.
Now I haven't had a chance yet to see how good the antenna
works on 160 aside from SWR/bandwith weasuring but tonight
on 80 the antenna seemed to hear pretty well - I'm hearing a lot
of 1, 2, 3 & 6 calls all over the band. If the bricks are absorbing
signals they're not doing too much damage. I'm hearing WWVH
on 5 mhz ok, also and I'm hearing a lot of DX AM broadcast
band stations - It's amazing how crowded that band is at 4 am!
Now I do have the option of taking 1 leg and running it away
from the bricks to a nearby tree but the other has to stay where
it is - that leg runs most of it's length about 5' away from the
wall due to the shape of the building. Problem is that the tree
is on the neighbor's property so that's probably out.
Anyways, the performance seems nominal and I don't have
many choices so I guess I'll have to be satisfied with what
I've got.
72's de Ken KG0WX