One advantage (for me at least) of using this material is that the physical
properties are better defined than a typical steel mast.
At least where I live Aluminum seems to be easier to obtain than steel with a
defined yield strength. The lighter weight can be a plus as well.
You just need to be sure of the Aluminum alloy you are getting.
----- Original Message ----
From: W3YY <w3yy@cox.net>
To: w8zn@comcast.net; TowerTalk@contesting.com
Sent: Thursday, February 26, 2009 2:03:18 PM
Subject: Re: [TowerTalk] Mast material
I too have used this mast material for over thirty years. For moderate
sized installations it is wonderful. Lightweight, doesn't rust, easy to
drill, relatively low cost, and seems to handle the wind pretty well. The
most I ever put on in was a shorty-forty up ten feet, but still no bending.
BTW, W3LPL doesn't use this material as a mast. It's part of the ELEMENTS
on his 40-meter beams! Now that's an antenna!
73, Bob - W3YY
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of w8zn@comcast.net
Sent: Thursday, February 26, 2009 1:17 PM
To: TowerTalk@contesting.com
Subject: Re: [TowerTalk] Mast material
Don't overlook 6061T6 aluminum - 2" OD with .25 or .375 wall thickness.
Lightweight (relatively), no, you can't put a monoband 40m beam 10 feet
above a thrust bearing but within the specs, it works very well. No rust,
clamps well to prevent slipping, exactly 2" OD so it fits well. Great for
VHF and smaller HF antennas. I had a pair of 36 foot long 6m antennas on one
for many years in Ohio, one was 22 feet out the top of the tower, it
survived 60+ mph winds, it bent in the wind but sprung back. Last I know
these were less than $200 for a 24 foot long section. No comparason to the
chrome molly masts for strength but probably 1/4 to 1/3 the weight.
Terry
----- Original Message -----
From: "jimlux" <jimlux@earthlink.net>
To: "k2vi" <k2vi@cox.net>
Cc: TowerTalk@contesting.com
Sent: Wednesday, February 25, 2009 11:53:18 PM GMT -05:00 US/Canada Eastern
Subject: Re: [TowerTalk] Mast material
k2vi wrote:
> Hey guys, can someone please advise me on the mast to use, I was
> looking at 2" EMT pipe I saw in the electrical dept at home depot.
> Keep in mind this pipe will be supporting a hy-gain 203BA which has a
> 16' boom and weighs 32# also it will be pushed up from the thrust
> bearing about 6'. Im sure it will be fine here in va beach. Right now
> im using a galvinized 2" shedule 40 pipe that weighs a ton.
>
EMT is pretty thin wall, and structurally not all that hot. After all, it's
really only designed to protect wires from abrasion. For instance, you can't
use it to support an electrical box holding a duplex receptacle sticking out
of the ground.
I've built structures from EMT (like a big geodesic ball), and it tends to
split along the weld, for instance.
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