On 11/29/2011 1:52 PM, Rick Karlquist wrote:
> Dan Hearn wrote:
>> I have several UST crankup towers. As they extend, all sections extend
>> proportionally. Do some other brands of towers extend each section
>> completely before the next section extends? That would sure make it easier
>> to access the rotor for replacement.
>>
>> --
>> Dan Hearn
>> N5AR
> That sure would be nice. I think it is a safe bet to say
> that if it were practical to do that, we would already see
> towers being made that way. I have seen some military tubular
> masts that work that way, but the cabling is very complicated
> and not conducive to holding a lot of weight.
The cabling would be simple. The lift would be proportional the the
weight and resistance to moving of each section.
The natural tendency would be for the lighter sections to go up first
and heavier to come down first. Simple tubular masts work this way. OTOH
if the top section
has an antenna that makes it weigh more that the lower sections it will
be the last to raise.
For towers that do not work that way, just block the lower sections even
if you have to raise them a few feet. Once they are secured the top section
will extend. Talk this over with the tower manufacturer first though.
73
Roger (K8RI)
>
> UST told me it was OK to extend my 106 foot tower to the necessary
> 50 feet or so to access the rotor. Of course you want to have
> the bottom section resting on timbers, rather than being supported
> by the tilt over winch. At first it seemed dicey to have all
> that tower cantilevered out, but I've done it a few times without
> incident.
>
> Rick N6RK
>
> Rick N6RK
>
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