In a message dated 96-03-21 23:49:27 EST, you write:
>Does anyone have any experience with this? Specifically
>can I make this suggestion in good faith? I am looking
>for information on tower paints (other than ORANGE and WHITE)
>that would hold up on a galvanized steel surface and wouldn't
>hamper my safety and ability to climb the tower.
>
Hiya, J.P. --
My experience has been that even real live tower paint will flake off of a
poorly prepared galvanized tower so the prep is the key to success. Here in
PC Washington State, we have cellular towers that are painted sky blue (or
gray to match the real sky color) and water towers that have trees painted on
the sides of them. The point is that any color is more acceptable than
galvanized steel. A light blue seems to work best here.
You'll have to wipe it the tower down with a solvent or metal cleaner in
order to take off any contaminants and excess zinc from the galvanizing
process. The paint won't adhere if you skip this step. Whether you put on a
primer coat is up to you. Talk to your local specialty paint store and see
what they recommend. In fact, talk to a couple of them. There are paints
that they call "self-priming" that might be helpful. The coating, BTW, will
help to preserve the galvanizing and practically eliminate any oxidation.
There are a bunch of coatings that may be suitable including enamel, epoxy,
etc. Find something suitable and economically viable.
The paint can be applied with a brush, paint mitt or sprayed. If you can
get the building department to buy into this solution, it's a small price to
pay IMHO.
73 and good luck, Steve K7LXC
>From john.devoldere@innet.be (John Devoldere) Fri Mar 22 18:11:15 1996
From: john.devoldere@innet.be (John Devoldere) (John Devoldere)
Subject: Beverages and horizontal orientation
Message-ID: <199603221812.TAA12527@mail.be.innet.net>
>Hi John,
>In a message dated 96-03-21 21:52:34 EST, you write:
>
>>Here is my experience. I have been using beverages for more than 25 years. I
>>have a 4 square for 80 since 3 years, and a single 1/4 wave vertical for
>160.
>
>I have also been using them for a similar time period, since the early 70's.
>
>>On 160 I always use the Beverages. They are so vastly superior to the
>>vertical, that I NEVER use the vertical. I have 12 Beverages, one per 30
>>degs, and each is 600 to 1100 ft long (approx), and 6 ft high.
>
>That's interesting. My experience is that in a quiet rural location, the
>Beverage is very little improvement over a simple vertical. Perhaps 3 or 4 dB
>at maximum when there is no QRN from storms. But in a suburban location the
>difference was always larger. Four end fire loops (an array two hundred feet
>long) ALWAYS beats the 500 ft or longer Beverages.
>
I always thought this was a quiete area, it's in the country, about 10 km
from city and major industry, HV power lines at 5 km from here... My S/N
improvement is at last 10 to 15 dB over the vertical on 160.
>>On 80, the Beverages outperform the 4-square 98 % of the time. I must admit
>>though that my 4-square is NOT optimized for maximum low angle. Using
>>(intentionaly!) only one radial on each vertical. I have some high-angle
>>radiation from the array, which of course deteriorates its receiving
>>performance. It was done intentionally as to give our signal a little more
>>"presence" in Europe during contests. If I had not Beverages, I would
>>probably not have done this. The 4-square will only beat the Beverages hours
>>after sunrise of hours before sunset, when the signals are so weak that I
>>need the additional gain of the 4-square.
>
>I understand your goal, it's a great idea during transmitting.
>
>But how do you prevent the four square from picking up feedline noise with
>such a poor grounding?
what is feedline noise??? When you used an elevated radials system (whether
one or more), you should never connect the radials to the "real" ground
because otherwise your return currents will not only flow in the elevated
radials but also (partially) in the real ground. So you must decouple the
feedline outer braid by using so-called current baluns in each of the 4
feedlines at the feedpoint. Of course the aouter braid is grounded in the
center of the 4-square, where I have the Collins hybrid coupler. there it is
gr9ounded to the radial system of the 160 meter vertical, which consists of
250 radials, ranging from 60 to 300 ft in length (all buried just an inch or
so).
And certainly the intentional high angle response
>destroys some of the directivitity responsible for low noise and QRM on
>receiving!
Sure, but like I explained that was intentionally. It now also hear the
local stuff better. I am not only an avid DX-er, this is also a major M/S
(and single OP) contest station (one of the best in Europe, I think). So
contesting was one of the primary design parameters.
On 20 meters I feed a vertical mounted above my beam with 6 dB of
>power division to keep locals away. But I think these systems make very poor
>receiving antennas! On 20 I disconnect the vertical when receiving, but you
>can not disconnect your single radiating radials!!
I could if I wanted. Just have two radials in line, and disconnect one on
transmit. But, again, the array was designed with only transmit in mind. The
day I won't be able to put up may Beverages, I will probably reason
differently.
>
>>BTW, the 1100 ft long Bevberags ALWAYS outperform the short ones. In my case
>>1100 ft is definatley not too long, not even for 80 meters.
>
>When I measure the current here on a 500 ft Beverage, the power loss is 6dB
>per 500 ft. In high conductivity soil the loss was only a little less. I
>suspect the reason my reception has never improved with a longer antenna is
>the large loss. Comparing a 500 foot Beverage to a longer Beverage made no
>difference at all in A/B tests here, except for normal diversity fading that
>only lasts a few minutes.
>
It IS very different here!
>As a question John, I wonder if perhaps sometimes Beverages are not
>terminated as well as they could be? In that situation, longer lengths would
>improve termination and reception from the lowering of standing waves by the
>added losses.
>
I use an HF network analyser and look at the return loss on the feed system.
With proper termination it is very good over a broad range.
>Many people find 4 squares better or even two element vertical arrays better,
>that seems to be the rule rather than exception. I know that a dipole at 300
>feet always beat any Beverage I had, and four small loop antennas in an end
>fire array also do that.
>
Maybe, I have not done that test. There must be guys in Europe having
"Ggood" 4-squares, and high dipoles and the like, but I always seem to come
to the conclusion that my hearing is one of the best. Using Beverages, hi...
>But since good ways to model or measure receiving antennas are difficult to
>find, it's a lot of peoples gut feelings, hi. I also wonder how much
>information comes from antennas that are not installed correctly, with proper
>feedline decoupling and so on. I never hear of people decoupling feedlines on
>Beverages, and that is very important unless the feedpoint grounds are *very*
>good.
True!
>
>73 Tom
>
>
73
John
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Call us in all major 1996 contests: ON4UN (OT6T in WPX)
John Devoldere (ON4UN-AA4OI)
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