K1TTT wrote:
> In my rohn catalog the self supporting height for 25g in 70mph area with no
> ice is only 40'... still a bit short for 80m.
>
My old one says that, but my newer one says "Not self supporting at any
height" for both 25 and 45G. OTOH they let you go IIRC a bit less than
30' above a house bracket unguyed for 45G.
As an opinion, not a recommendation:
If I could afford to lose the tower, it wouldn't fall on any one or
anything if it went down (and I could guarantee no one could get within
range), then I'd put up 60' of 25G as a grounded tower with a hefty
concrete base if I could stand it in one piece. It's not something that
should be climbed. No one would insure it if they understand towers and
there is a big liability issue
73
Roger (K8RI)
>
> David Robbins K1TTT
> e-mail: mailto:k1ttt@arrl.net
> web: http://www.k1ttt.net
> AR-Cluster node: 145.69MHz or telnet://dxc.k1ttt.net
>
>
>
>> -----Original Message-----
>> From: Allen R. Brier [mailto:n5xz@earthlink.net]
>> Sent: Monday, April 13, 2009 20:39
>> To: towertalk@contesting.com
>> Cc: 'Rick Hiller'
>> Subject: [TowerTalk] Rohn 20/25G leg insulator material
>>
>> I wish to build an 80 meter vertical using some Rohn 20G sections I have
>> in
>> storage. In the past there was some mention of insulating material that
>> could be used at the base. If possible, I would like to get that
>> information
>> again from the group. I would like to make the vertical self supporting
>> i.e.
>> no guys (bosses request). Will the material be strong enough for that?
>>
>> In addition, what would be a good recommendation for the vertical
>> configuration, i.e. how many 20G sections and how much of a stinger on
>> top?
>> Obviously maximum bandwidth and efficiency is the goal and I operate
>> mostly
>> CW.
>>
>> Next, I would also like to consider using the same antenna on 160 meters,
>> by
>> switching in a loading coil at the bottom. I know this isn't optimal, but
>> I
>> would like some recommendation for how much inductance in would need, or
>> the
>> coil configuration (full legal limit, of course). Other recommendations
>> would also be appreciated.
>>
>> Finally, I also have a 70 foot crank-up tower with a 4-el SteppIR on top
>> that could be shunt fed. If I did shunt feed the tower, what would be the
>> optimal distance between them for phasing purposes?
>>
>> A lot and questions in one email but I would appreciate any and all
>> advice.
>>
>> 73,
>>
>> Allen Brier N5XZ / KL5DX
>> 1515 Windloch Lane
>> Richmond, TX 77406-2533
>> 281-342-1882
>> 713-705-4801 (Cell)
>> n5xz@arrl.net
>>
>> _______________________________________________
>>
>>
>>
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>
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