Stan Stockton wrote:
> Just my opinion.... 1.5 inch schedule 40 may be fine if you have some
> big tribander or 35 foot monobnder and it is mounted right above the
> top bearing. If you are stacking antennas on the mast, forget it.
http://www.rogerhalstead.com/ham_files/Tower29.htm shows a tribander at
100', 7L 6-meter Yagi at 115 and a 14' cross boom at 130' holding a pair
of 11L on 440 and pair of 12L 144. That all on 2" schedule 40 but it's
structural steel. It's a bit flexible with the top looking like a blue
gill rod that just tied into a big Bass, but it's withstood over 70 mph
winds and many occasions.
I'm going to a heavier wall DOM so it doesn't beat the antennas to
death, but strength wise it seems to have been more than sufficient.
OTOH it's not ordinary schedule 40 pipe which is relatively soft and
easily bent.
>
>
73
Roger (K8RI)
> For years I had a 1.5 with a 1.25 telescoped inside and welded on both
> ends. All was fine with a very large monobander just above the top of
> the tower until a big ice storm broke one side of a boom truss. Then
> the imbalance bent the mast. Had the truss support remained intact,
> I think all would be fine. Certainly I believe using an expensive
> mast on a tribander of any size mounted right at the top of the tower
> is a waste of money.
>
> Stan, K5GO
>
> Sent from Stan's IPhone
>
> On Mar 18, 2010, at 4:21 PM, "Robert West"
> <robert.west@eatmoresoap.com> wrote:
>
>
>> Again, this stuff hasn't seemed thin at all. Now if I was using the
>> 2" EMT,
>> THAT is definitely thin. So far it's been solid for me.
>>
>>
>>
>> -----Original Message-----
>> From: towertalk-bounces@contesting.com
>> [mailto:towertalk-bounces@contesting.com] On Behalf Of Julio Peralta
>> Sent: Thursday, March 18, 2010 7:36 AM
>> To: 'Tower and HF antenna construction topics.'
>> Subject: Re: [TowerTalk] 2" O.D. Pipe???
>>
>> I once had a major problem using fence post material for a mast. It
>> bent
>> just above the top of the tower and became a real problem to take
>> down. The
>> material is very thin and not very strong.
>>
>> Julio, W4HY
>>
>> -----Original Message-----
>> From: towertalk-bounces@contesting.com
>> [mailto:towertalk-bounces@contesting.com] On Behalf Of Robert West
>> Sent: Wednesday, March 17, 2010 10:32 PM
>> To: 'Tower and HF antenna construction topics.'
>> Subject: Re: [TowerTalk] 2" O.D. Pipe???
>>
>> I use Chain Link Fence posts from Home Depot. It's 2" outside
>> diameter and
>> looks to be DOM.
>>
>> Bob-
>>
>>
>> -----Original Message-----
>> From: towertalk-bounces@contesting.com
>> [mailto:towertalk-bounces@contesting.com] On Behalf Of EZ Rhino
>> Sent: Wednesday, March 17, 2010 6:41 PM
>> To: Tower and HF antenna construction topics.
>> Subject: Re: [TowerTalk] 2" O.D. Pipe???
>>
>> You need tubing not pipe. Pipe is measured by ID, tubing by OD.
>> You want
>> DOM (drawn over mandrel) tubing, which is only available at steel
>> suppliers,
>> not Home Despot.
>>
>> Chris
>> KF7P
>>
>>
>>
>>
>>
>>
>>
>> On Mar 17, 2010, at 16:36 , k2qmf@juno.com wrote:
>>
>> Hello All,
>>
>> I went in search of 2 Inch O.D. pipe
>> on the internet!!
>>
>> Guess what? I can't find any!!!!
>>
>> The outside diameter of pipe is
>> either 1.9" O.D. for 1.5 inch pipe or
>> 2.375" O.D. for 2 inch pipe!!!
>> Nothing in between....
>>
>> What am I missing??
>>
>>
>> Thanks for any help for the uninformed...
>>
>> 73,
>> Ted K2QMF
>> ____________________________________________________________
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