I'm considering a weekend cabin on the Ohio River.
My question is two fold (and possibly twice dumb)

There is an unused cistern on the property and the property is on the
shore of the Ohio River.

Question 1:

If the cistern is filled with salt water, would the near field of a
vertical be significantly enhanced? Would it lower the TOA?

Question 2:

Does significant flow in a body of water (in this case, the Ohio River)
represent a different dielectric than ground or non-flowing lake water?
How would it effect propagation from a vertical or other antenna system?

Thanks!

John
AB8O

On Sun, 10 Sep 2006 23:10:52 -0400, jawod wrote:

If the cistern is filled with salt water, would the near field of a
vertical be significantly enhanced?

Hi John,

No.

Would it lower the TOA?

No.

Does significant flow in a body of water (in this case, the Ohio River)
represent a different dielectric than ground or non-flowing lake water?

No.

How would it effect propagation from a vertical or other antenna system?

A vertical would propagate better, at lower angles, along the length
of the water ("along" being in the straight line from the radiator, to
the water, and across, or along the water on the same extended line).

The water, if you will, acts as a "reflector" because it has a huge Z
mismatch to the air above it (more than 10:1, if I recall) and not
because it has some miraculous conductivity (it doesn't). Salt water
also creates illusions of conductivity. Actually, yes it is better
than an insulator, and adds loss galore in comparison. The inherent
beneficial property is that it has an even higher mismatch to the air
above it which aids reflection at lower angles of vertical
polarization.

Now, the distinction is that in the near field, water and sal****er
are ****-poor (pun intended) conductors. You would be better off in a
desert of dry sand, a very poor conductor. On the flip side, at a
distance (where radiation lobes are developed) water and sal****er are
huge sources of low angle propagation for vertically polarized
radiation.

Moral: transmit from on high a sand dune, out over the ocean (or
lake).

73's
Richard Clark, KB7QHC

If the cistern is filled with salt water, would the near field of a
vertical be significantly enhanced?


No

But your vegetable garden is toast.

BTW
There are no new questions, only new fools.

73
H.
NQ5H

Richard Clark wrote:
In his usual succinct manner,


No.
No.
No.


Now, the distinction is that in the near field, water and sal****er
are ****-poor (pun intended) conductors.
How did you intuit that I intended to urinate into the cistern?

On Sun, 10 Sep 2006 23:10:52 -0400, jawod wrote:

I'm considering a weekend cabin on the Ohio River.

John, I'm glad you cleared up the question you just raised with the above
sentence. You see, property on the shore of the Ohio River is considerably
different than 'on the Ohio River'.

snip
Question 2:

Does significant flow in a body of water (in this case, the Ohio River)
represent a different dielectric than ground or non-flowing lake water?
How would it effect propagation from a vertical or other antenna system?

John
AB8O

Well John, the flow in a body of water would not change the dielectric constant,
but the signal arriving in the direction of the water flow would arrive earlier
than that arriving in the opposite direction. I'm sure measurements using the
inverse doppler principle would show a significant difference in the arrival
times, especially if the flow rate at the bottom equals that at the surface.

Walt, W2DU.

On Mon, 11 Sep 2006 10:48:20 -0400, Walter Maxwell wrote:

On Sun, 10 Sep 2006 23:10:52 -0400, jawod wrote:

I'm considering a weekend cabin on the Ohio River.

John, I'm glad you cleared up the question you just raised with the above
sentence. You see, property on the shore of the Ohio River is considerably
different than 'on the Ohio River'.

snip
Question 2:

Does significant flow in a body of water (in this case, the Ohio River)
represent a different dielectric than ground or non-flowing lake water?
How would it effect propagation from a vertical or other antenna system?

John
AB8O

Well John, the flow in a body of water would not change the dielectric constant,
but the signal arriving in the direction of the water flow would arrive earlier
than that arriving in the opposite direction. I'm sure measurements using the
inverse doppler principle would show a significant difference in the arrival
times, especially if the flow rate at the bottom equals that at the surface.

Walt, W2DU.

A caveat to the post above: An important issue concerning the above issue
escaped me during that writing. The inverse doppler principle is thwarted in
Pittsburgh at the point of confluence of the Allegheny and Monongahela Rivers
that spawn the Ohio River, because those two rivers flow in different
directions, causing the measurement device to become confused in the Pittsburgh
area.

Walt, W2DU