The water tank is a convex surface (at least on the side you can get to) not
a concave surface. However offhand I don't think that you will be able to
get far enough away from the surface of the tank to illuminate it properly
and the curvature will most likely not be anywhere near optimum for the
I'd suggest you consider the water tank as a reflector of the type called
Gregorian after James Gregory of England who devised it about 1660, and the
operation of which is described in the book Antennas for all applications by
John Kraus 3rd edition on pp. 680-684.
Illumination of the
_
From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of Dave VanHorn
Sent: Monday, January 29, 2007 4:26 PM
To: Repeater-Builder@yahoogroups.com
Subject: [Repeater-Builder] Re: Antenna on the side of a water tower
--- In Repeater-Builder@
skipp025 wrote:
Which reminds me that I should have mentioned the available scan
of club using a series of yagi antennas around a wide tower to
obtain a quasi omni pattern. You can probably find the info
on the repeater builder antenna page along with the mounting offset
paper I
Ok, the sector thing is interesting, but we've drifted FAR away from
the question I was trying to answer.
Can anyone direct me to information, or modeling software (preferrably
free) that can predict the pattern of an omni antenna, at various
distances from a large cylindrical water tower?
Dave VanHorn wrote:
I would suggest 1/2 wave away from the surrounding metal as a
minimum, but try and get as far away as you can.
Yes, but what's bugging me is that I'm sure there are BAD distances,
especially up close within 1-2 wavelengths
Normally for side-mounting on a normal
Normally for side-mounting on a normal tower, one wavelength will
get
you close to an omni pattern,
I'm not trying to get to an omni pattern, I know that's impossible.
What I want to do is approximate the pattern that I will get, and look
at that (using RM) against the terrain, and see
Laryn Lohman wrote:
Now that I think about it, with all the wireless stuff (cell
antennas) that I have seen mounted around a water tower single legs
(the modern towers), on buildings at each face, etc. , I bet there is
info out there that you can tailor for your needs using the phased
--- In Repeater-Builder@yahoogroups.com, gervais fillion
[EMAIL PROTECTED] wrote:
Dave
gave us the model of your antenna,is it the 4 loops on a 20 feets
mast
antenna?
The VHF is a Telewave ANT150D9, and UHF is a DB-404 (unless I find
something better before then)
--- In Repeater-Builder@yahoogroups.com, Steve Peg [EMAIL PROTECTED]
wrote:
It is what you get when the county takes a free site, when better
ones existed. Cheap, free is always better to people who know nothing
and dollars count.
Well, in my case, we've been looking for two years, and
--- In Repeater-Builder@yahoogroups.com, Iszak, Mike [EMAIL PROTECTED]
wrote:
Dave;
Are you able to choose where on the side of the tank (IE, facing a
particular direction) or are you stuck with a specific spot?
I haven't seen the details yet, but as far as I know we can pick the
spot.
hummm
goggle dont find this antenna,,,
Original Message Follows
From: Dave VanHorn [EMAIL PROTECTED]
Reply-To: Repeater-Builder@yahoogroups.com
To: Repeater-Builder@yahoogroups.com
Subject: [Repeater-Builder] Re: Antenna on the side of a water tower.
Date: Mon, 29 Jan 2007 20:30:27 -
In fact, it's normal these days that when you see banks of cell antennas on
each side of a structure, each bank feeds a different bank of tx/rx; in
other words, each bank is a different cell site.
They are called sectors. Out here in LA, sites consist of 2, 3 or 4
sectors. On PCS 1950, each
They are combined. Nextel does this and calls it a Quasi-Omni site. There
are some drawbacks to it, but it actually works quite well. Most panel
antennas used are 90 or 65 degree antennas. The biggest drawback is the 6dB
hit that you take on receive and some strange nulls between the
Which reminds me that I should have mentioned the available scan
of club using a series of yagi antennas around a wide tower to
obtain a quasi omni pattern. You can probably find the info
on the repeater builder antenna page along with the mounting offset
paper I mentioned earlier.
skipp
--- In Repeater-Builder@yahoogroups.com, skipp025 [EMAIL PROTECTED]
wrote:
Which reminds me that I should have mentioned the available scan
of club using a series of yagi antennas around a wide tower to
obtain a quasi omni pattern. You can probably find the info
on the repeater builder
However, if that is all you can get, then go for it. I have seen guys
mount a Rohn 25 type tower on the platform where the railing is, mount
the antenna on top of the tower section(s) and then the top of the
antenna will see over the top of the water tower.
Problem is, there's a fire repeater
Dave VanHorn [EMAIL PROTECTED] wrote:
Can anyone point me to something that will show me the antenna pattern
for a VHF and UHF antenna mounted on the side of a water tank at
different distances from the tank?
I've been offered a site, but I can't have top mount, I
More information would be helpful , when you say side is that same
level as
the tank or looking above it with side diplacement ?
The first case, besittin' beside of it as Andy Griffith would say.
More information would be helpful , when you say side is that same
level as
the tank or looking above it with side diplacement ?
The first case, besittin' beside of it as Andy Griffith would say.
Skipp,
I sure would appreciate your sending to me the PDF file scan of the Sinclair
paper.
Thanks,
73, Allan Crites wa9zzu
skipp025 [EMAIL PROTECTED] wrote:
Depends a lot on the size of the water tank, then the type of
antenna and its mounted distance from the tank. Not an easy
I don't think you are going to be able to model it to your satisfaction with
any software you or I could afford. Perhaps you need to adopt an empirical
approach, put up an antenna and see what you get. Drive test it, take field
strength readings, plot and graph the real world data as much as
This idea was in a ham magazine years ago, to solve a similar problem. It was
on a very large tower, with a large face. This particular application used
three sets of phased beams (two at each leg, fired tangentially to the tower).
You have to start out with a bunch of gain at each leg, not
--- In Repeater-Builder@yahoogroups.com, Roger White
[EMAIL PROTECTED] wrote:
I am thinking it was not in QST but maybe one of the ham technical
mags that is still no longer around.
Seems like it was Ham Radio Magazine. Don't know which issue; early
80s, maybe? I may have it around here
Somehow I recollect that describing the 'extremely healty' Clarkston
machine (near Detroit) ~ 3 TX yagis a single RX stik atop...
Roger White wrote:
This idea was in a ham magazine years ago, to solve a similar problem.
It was on a very large tower, with a large face. This particular
I remember that article and I was going to do something similar on a wide
faced tower that I was trying to get space on. It was a CATV head-end
tower that was full of log periodic antennas, the only available height was
from 125 feet to the bottom. I almost got the project started when the
Joe,
I don't think those three panel antennas are combined at all. Most cellular
and PCS providers are using 120-degree panel antennas to cover three
120-degree sectors, each with its own base station, effectively tripling
their capacity. The older omnidirectional antenna cell sites- usually a
At 1/27/2007 10:45, you wrote:
I don't think you are going to be able to model it to your satisfaction with
any software you or I could afford. Perhaps you need to adopt an empirical
approach, put up an antenna and see what you get. Drive test it, take field
strength readings, plot and graph the
Depends a lot on the size of the water tank, then the type of
antenna and its mounted distance from the tank. Not an easy guess
unless you have a lot of math background with some serious extra
time.
Most people wing it' trying horizontal mount spacings from
1/4 to 1/2 wave (or multiples
It's also at the repeater-builder web site on the antenna systems page, or
directly at
http://www.repeater-builder.com/antenna/antenna-mounting-guidelines.pdf
Mike WA6ILQ
At 03:11 PM 01/26/07, you wrote:
Depends a lot on the size of the water tank, then the type of
antenna and its mounted
It's hard to put into text.
What I'd like to do, is get back to the more omni pattern if at all
possible. The way everything is situated, if I put the antenna on the
side of the tower facing through most of our coverage area, I think it
will end up with too much gain in that direction,
--- In Repeater-Builder@yahoogroups.com, skipp025 [EMAIL PROTECTED]
wrote:
Depends a lot on the size of the water tank, then the type of
antenna and its mounted distance from the tank. Not an easy guess
unless you have a lot of math background with some serious extra
time.
I can deal
--- In Repeater-Builder@yahoogroups.com, Mike Morris [EMAIL PROTECTED] wrote:
It's also at the repeater-builder web site on the antenna systems
page, or
directly at
http://www.repeater-builder.com/antenna/antenna-mounting-
guidelines.pdf
Ok, no that dosen't really get me where I need to
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