[Towertalk] 20M Yagi
WD4K
WD4K_1@Bellsouth.net
Tue, 16 Jul 2002 11:40:04 -0600
First, thanks for all of the really good info. I should have explained my
purpose for this yagi a little better. I already have a 110' Rohn 55 going
up now with a three stack of C31XR's 35',75',115', Mag340N @110' and 180B
@124'. SO, that tower is full. The building of the 20M 5 or 6 el for tower 2
is to augment what I have and free up the stack for other duties as needed.
C31's are only 3 el on 20M, so I wanted a little more umph on 20 when
conditions are favorable. I also have several 4 and 5 El 10 and 15M yagis
and may add them to the second or third tower but that is another topic
altogether. What I really need is a design suggestion for building the 20M.
I have a 4 EL KLM 40M that I am not using and may sell it or may try to use
the 42 boom and aluminum boneyard to build the 20M. Thanks for the excellent
info on the site and the modeling/height considerations. The collective
knowledge of this group is amazing. 73, Tommy WD4K
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Today's Topics:
1. Re: Source for SS bolts, nuts, lockwashers (GALE STEWARD)
2. =?iso-8859-1?Q?Re:_[Towertalk]_20M_Yagi_=3F?=
(=?iso-8859-1?Q?i4jmy@iol.it?=)
3. Re: 20M Yagi ? (Pete Smith)
4. K1IR gets an A plus (Jim White, K4OJ)
--__--__--
Message: 1
Date: Tue, 16 Jul 2002 08:14:15 -0700 (PDT)
From: GALE STEWARD <k3nd@yahoo.com>
Subject: Re: [Towertalk] Source for SS bolts, nuts, lockwashers
To: towertalk reflector <towertalk@contesting.com>
Also try SMALL PARTS INC.at
http://www.smallparts.com
They have hex head machine bolts & screws (with
associated nuts, washers, etc.) from sizes #0-80 thru
1/2-13. They have lots of other material that can be
used for antenna "stuff".
73, Stew K3ND
> Looking for a source of reasonably priced stainless
> steel items per the
> above, in low quantities - 50 each, size 8-32 up to
> 1/4 - 20.
>
> Mark W9UZ
> _______________________________________________
> Self Supporting Towers, Wireless Weather Stations,
> see web site: http://www.mscomputer.com
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> saw this ad and take an additional 5 percent off
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Message: 2
Date: Tue, 16 Jul 2002 17:33:00 +0200
From: "=?iso-8859-1?Q?i4jmy@iol.it?=" <i4jmy@iol.it>
To: btippett@alum.mit.edu
Cc: WD4K_1@Bellsouth.net
Cc: towertalk@contesting.com
Subject: [Towertalk] =?iso-8859-1?Q?Re:_[Towertalk]_20M_Yagi_=3F?=
In case of a 200/300' real drop, and 800' hill top location, it's quite
possible that the first reflection is so far that the equivalent height
of the antenna/s from ground is 800'.
In such case stacking will affect gain but is almost useless for null's
coverage and to obtain a smooth and wide lobe or higher angles
radiation, ground is anyway too far down.
I didn't try or study it, but I think a vertical polarization could be
a (compromise) solution for high angles and smooth wider lobe at a
sacrifice of some gain, in such peculiar cases.
On the other end an height of 800' is already in excess of 10 WL, lobes
and nulls will be at so close intervals (few degs) making the situation
less critical than one might think in the other cases.
73,
Mauri I4JMY
> WD4K wrote:
> >The qth here is on an 800' hilltop with 200-300' drop and horizon
> in the three main directions. Any suggestions before I start planning
> this next project?
>
> This is a very complex question best answered with:
>
> 1. N6BV's Terrain Analysis (YT) available with recent ARRL Antenna
> Handbooks (but it does not handle out of phase antennas).
>
> 2. NEC modeling of two stacked yagi's with BIP/BOP (both in phase
> and both out of phase) as well as the individual patterns.
>
> 3. Actually, K6STI's Terrain Analysis (TA) would be the very best
> since it combines 1 and 2 above, but I'm not sure Brian is still
> selling it. His e-mail is k6sti@n2.net
>
> My personal guess is that you would be better off with two
> medium Yagi's (like 204BA's) at 40' and 90' with the ability to do
> either and BIP/BOP than you would with a single monster Yagi. Given
> your effective height, you have to be careful to not get only low
> angles. From here in NC, there are two predominant angles to Europe
> on 20 meters (1-3 degrees and 7-8 degrees) and a single antenna will
> probably not cover both well.
>
> 73, Bill W4ZV
--__--__--
Message: 3
Date: Tue, 16 Jul 2002 11:32:28 -0400
To: towertalk@contesting.com
From: Pete Smith <n4zr@contesting.com>
Subject: Re: [Towertalk] 20M Yagi ?
At 02:36 PM 7/16/02 +0100, Bill Tippett wrote:
>WD4K wrote:
> >The qth here is on an 800' hilltop with 200-300' drop and horizon
>in the three main directions. Any suggestions before I start planning
>this next project?
>...
> My personal guess is that you would be better off with two
>medium Yagi's (like 204BA's) at 40' and 90' with the ability to do
>either and BIP/BOP than you would with a single monster Yagi. Given
>your effective height, you have to be careful to not get only low
>angles. From here in NC, there are two predominant angles to Europe
>on 20 meters (1-3 degrees and 7-8 degrees) and a single antenna will
>probably not cover both well.
In his book Dave Leeson discusses the downward-sloping foreground in some
detail (chapter 10). For example, he shows a table of takeoff angle vs
signal for a single 14-mhz yagi 100 feet over a 12 degree downward sloping
foreground. The level remains within 2 dB from 2 to 18 degrees, while the
same antenna, at the same height over flat ground, is down 6 dB at the two
extremes. In other words, the sloping foreground has much the same effect
as a stack, in terms of broadening the forward lobe. He also cautions that
in this situation it is quite easy to get your antenna too high.
Worth reading!
73, Pete N4ZR
--__--__--
Message: 4
From: "Jim White, K4OJ" <k4oj@tampabay.rr.com>
To: "Jim Idelson" <k1ir@designet.com>,
"TowerTalk Post" <towertalk@contesting.com>
Cc: <fcg@mailman.qth.net>
Date: Tue, 16 Jul 2002 11:45:25 -0400
Subject: [Towertalk] K1IR gets an A plus
This is perhaps one of the best posts I have seen from a news group, ever
(other than those about the Florida QSO Party).
K1IR has done very well in summarizing how to do it right...this is similar
to the procedure used by W1CW and W1YL after hurricane Andrew devistated
their Homestead QTH a decade ago...like K1IR, W1YL provided documantation to
back up their claim - and they settled out very well.
If you have not read this post - re-read below, and maybe set up a pentaflex
folder - might behove some of us to start collecting this info ahead of time
to make the work load a little easier come claim time, God forbid!
Again, nice job Jim...
73,
Jim, K4OJ
Proud Member of the Florida Contest Group -congratulations to the top two US
finishers to WRTC 2002 - our own K1TO (+N5TJ) and N2NL (+N6MJ)...
----- Original Message -----
From: "Jim Idelson" <k1ir@designet.com>
To: "TowerTalk Post" <towertalk@contesting.com>
Sent: Tuesday, July 16, 2002 9:56 AM
Subject: Re: [Towertalk] ARRL Insurance
> Nothing like learning from experience . . .
>
> I have had several major lightning events over the past five years. My
> home-owners policy has a deductible around $500, but it covers everything.
You
> don't have to list equipment on the policy in advance. Lightning doesn't
> discriminate between ham equipment and other electronics and appliances
found
> in your home. This policy provides for replacement cost reimbursements,
and the
> adjustor has never had a problem with replacements that might reasonably
be
> more costly and up-to-date than the original equipment.
>
> When the dollar amounts start to rise, the insurance company will become
> interested in the potential scrap value of your completely destroyed radio
> equipment. They may ask you to give them the old equipment. But, when you
tell
> them of the extremely small market for your radio and the difficulty they
will
> have selling it, they might let you keep it for parts.
>
> I've never had outdoor antenna damage - it's always been the electronics
and
> computer equipment inside. But, I worry that a claim relating to the tower
or
> antennas might surprise the adjustor. So, I have informed the insurance
company
> of the existence of the tower, and I've shown them the completed building
> permit. This will help to show that the tower and antennas are insured
> property.
>
> How do you get maximum reimbursement for your losses? By far, the most
> important thing is to MAKE THE ADJUSTOR'S JOB EASY! An insurance adjustor
> spends the morning in the office doing paperwork and his/her entire
afternoon
> driving around looking at damaged things - things they don't care about at
all.
> Every insurance adjustor I've met really looks forward to quitting time.
They
> allocate a certain amount of time to every visit. If you can get him out
of
> your house early, he can get home early. Keep this in mind all the time.
>
> The adjustor will be looking for a few things during the visit:
> 1. Evidence of damages and the probable causes,
> 2. Evidence of your ownership of the damaged property and possibly
evidence of
> what you paid for it and when, and
> 3. Evidence of what it will cost to replace or repair the damaged item.
>
> Demonstrating that a device is damaged is important. If there is obvious
> physical damage, make sure it is apparent when the adjustor comes to
visit. The
> adjustor will usually be carrying a digital camera to take photos of the
> damage. Make that job easy. I have offered my own digital photos, and they
are
> often accepted by the adjustor. If the damage can't be seen, then do a
> demonstration. My FT-1000MP had charcoal on the back near the antenna
> connector, and when plugged in, it wouldn't come on at all.
>
> If an item is completely destroyed, you may be able to just say so, or you
can
> provide the written statement of a qualified repair shop. The insurance
> coverage will reimburse you for the cost of getting the equipment looked
at by
> the shop. You need to show that the equipment cannot be repaired for less
than
> the cost of replacement. The best news for you is sometimes that
replacement
> parts are no longer available, etc.
>
> Was there a big lightning storm or a major wind that caused the damage? It
was
> probably mentioned in the newspaper, or it was noted on the Weather
Channel
> website. Make a copy of an account of the circumstances that probably
caused
> the damage and give it to the adjustor.
>
> Evidence of ownership simply informs the adjustor that the damaged
equipment is
> truly yours. You can show receipts, credit card statements, etc, to show
that
> the stuff is yours. It's good to keep all documents when you buy a new or
used
> piece of equipment. If you don't need to show what you paid, you might
want to
> produce shipping documents that don't include price information.
>
> If the reasonable approach is to get the equipment repaired, show a repair
> estimate. If you want to replace the item, show evidence of the
replacement
> cost. The insurance company expects you to buy a new unit, not a used one.
If
> the damaged unit is no longer a current model, you should replace it with
the
> most comparable current version. This choice is essentially up to you. If
you
> provide specs in written form that can be used as evidence, the adjustor
will
> be happy. His goal, remember, is to fill the file with evidence. He
doesn't
> have to understand it.
>
> You and the adjustor also know that there is a wide range in repair and
> replacement pricing. You can choose to demonstrate low, medium or high
prices.
> For replacements, I have usually shown evidence obtained from the web of
prices
> ranging from discounted distributor prices to full list price. My "honesty
is
> the best policy" approach has usually resulted in maximum reimbursements.
The
> adjustor will look at the evidence, realize that he can get home early
[instead
> of doing price research back at the office], and he will thank you by
putting
> the list price evidence in his folder and telling you to put away the
> discounted pricing info because you might not be able to get the equipment
at
> that price.
>
> One more word of caution: Don't finalize your insurance claim too quickly.
The
> insidious and widespread results of a lightning event can go undetected
for a
> long time. I have found many damaged devices weeks after the claim was
closed
> out. You cannot then amend your claim or create a second claim for the
same
> event without a second application of deductible, so anything you find
later is
> your problem.
>
> I have found that the approach of doing all the homework for the adjustor
will
> get you the best possible results. It's a lot of work, but this is the
approach
> I recommend.
>
> The end result of your claim is a check made out to you from the insurance
> company. One thing you should know is that you are not required to spend
that
> money in the same manner that was used to calculate your damages. You can
spend
> it any way you want. If you decide to get out of 2M moonbounce, and
instead
> invest that money in your new 136KHz LF station, its not an issue for the
> insurance company.
>
> Although I have always felt good about the way things turned out with the
> insurance company, I would never choose to have a lightning strike. I've
lost
> extremely valuable and irreplaceable computer data, and spent huge amounts
of
> time documenting losses and preparing for adjustor visits. Right now, my
> station is not in use, and ALL my antennas are disconnected. All AC power
is
> supplied through a large UPS. When there's a thundserstorm approaching, I
shut
> down everything and disconnect every connection to the outside world. I
unplug
> all phone, ISDN and DSL lines coming into the shack. I unplug the UPS from
the
> wall. I am also looking carefully at investing in Polyphaser-type upgrades
to
> my grounding and lightning arrest system.
>
> I hope you don't ever have to go through this process, but if you do, I
hope
> these suggestions are helpful.
>
> 73,
>
> Jim K1IR
>
> ********** Forwarded Message **********
>
> [Towertalk] ARRL Insurance
> kk9a@arrl.net kk9a@arrl.net
> Mon, 15 Jul 2002 16:43:24 -0500
> Previous message: [Towertalk] Jim, good catch!
> Next message: [Towertalk] Cubex 2 element 5 band quad wire dimensions
> Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]
>
> Someone recently inquired about the ARRL insurance plan. I have a Yaesu
> FT1000MP Mark-V and a Kenwood TM-331 that were severely damaged my a
> lightning strike to one of my towers. The insurance has agreed to pay for
> the purchase of new radios. I also had some rotor and switchbox damage,
but
> since I don't list these items they were not covered. They were all
easily
> fixable my me anyway, except for the WX0B Stackmaster Control box which is
> toast. I'm happy with the policy.
>
>
>
> Previous message: [Towertalk] Jim, good catch!
> Next message: [Towertalk] Cubex 2 element 5 band quad wire dimensions
> Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]
>
>
>
> Jim Idelson K1IR
> email k1ir@designet.com
> web http://www.designet.com/k1ir
>
> _______________________________________________
> Self Supporting Towers, Wireless Weather Stations, see web site:
http://www.mscomputer.com
> Call 888-333-9041 to place your order, mention you saw this ad and take an
additional 5 percent off
> any weather station price.
> _______________________________________________
> Towertalk mailing list
> Towertalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
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