[TowerTalk] Klm 40m-1

[Larry]

I had a Force12 80M rotatable dipole which is a bit bigger (65 feet as I 
recall). It used loading wires that also served as a support truss. The mast 
ends of the truss were attached to the ends of a 3 foot piece of tubing 
centered on the mast and was nominally about 3 feet above the boom. That 
gives both vertical and some horizontal support. It survived the little ice 
we get here once in a great while. I have seen drawings of that kind of 
truss in ON4UN's book I think or perhaps it was the Physical Design book.

73, Larry  W6NWS

-----Original Message----- 
From: Stan Stockton
Sent: Thursday, January 28, 2016 10:18 AM
To: Rod Greene
Cc: towertalk at contesting.com ; Arnie Pfingst
Subject: Re: [TowerTalk] Klm 40m-1

A vertical truss does very little regarding survivability in wind.

It is absolutely necessary for survivability with significant ice load.

It can do more harm than good with ice if the vertical attachment point is 
not high enough, due to compression.  I've had booms and elements buckle up 
between the top of the tower and the attachment point as a result of not 
going high enough.

Stan, K5GO

Sent from Stan's IPhone



> On Jan 28, 2016, at 8:11 AM, Rod Greene via TowerTalk 
> <towertalk at contesting.com> wrote:
>
> Arnie,
> I have one of the old KLM 40m-1 antennas and have used it for years. So 
> far it has served me well. They do not normally need a truss support. I 
> don't know what the wind specs are for your area of the country, but for 
> the northwest where I am located, no truss is needed, nor called for in 
> the documentation.
>
> I don't think the antenna is anything to "write home about" but it is a 
> very good antenna for a shortened 40. And it handles and turns easily on a 
> tower. I have no idea how it would compare to a CushCraft.
> 73, Rod/w7zrc
>
>
>
>      From: Arnie Pfingst <arnie123 at hotmail.com>
> To: towertalk at contesting.com
> Sent: Wednesday, January 27, 2016 9:37 AM
> Subject: [TowerTalk] Klm 40m-1
>
>
>
> I have a chance to buy a klm 40m1 rotatable dipole. The fella said its on 
> the ground. He said he "refurbished it" he has some paperwork for it and a 
> 5kw balun with it. My questions are, does this antenna need a truss 
> support and how do I put one on, was this antenna really anything to write 
> home about. How does it compare to say... the cushcraft d40?Arnie
> Sent via the Samsung Galaxy S®6 active, an AT&T 4G LTE smartphone
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