The tram concept seems pretty cool... I suppose a
reasonably heavy duty three horizontal leg thing on the
ground with your pipe sticking straight up would do the
trick... then pre size your guy lines, and fix them to the
base of the rotator/antenna support tram and their anchor
points. Upon the tram reaching full height, the guy lines
will all become tensioned simultaneously, if sized right.
At any rate, the tipover hazard is minimized even as the
height of the tram increases, as the guy lines are getting
progressively tighter. Once at full height, the guy line
length may be trimmed as necessary to get your mast plumb.
Depending on the weight of your antenna farm and rotator,
the ground end of your guy lines may be adequately
tensioned with heavy duty cargo straps, or "come-along"
hoists. I think you are on to something here...
I have been working on the hardware required to safely
stand a light 55 foot crankup in a
portable environment, provided adequate anchor points are
available, and doing this all unassisted, without the tower
being fastened to a vehicle or a so-called "driveover"
mount. Quite the challenge I assure you. Trick is to fab
up some sort of "bipod" gin pole for lifting the top end of
the tower high enough for the line pulling the tower
vertical to get adequate mechanical advantage to do the
lift, and, not try to pull the tower to one side or
another. Other trick is to have the two back guys already
fastened to their anchor points so as to keep the tower
from doing anything silly when the tower becomes nearly
vertical, like fall over to one side or towards the winch
line. I am sure it can be done with the right stuff...
Eric
KB7DQH
On Thu, 25 May 2006 08:34:05 -0700 (PDT)
steve d <kc8qvo@yahoo.com> wrote:
> Hello, I am once again headed to my family's place on
> Lake of the Woods in Ontario Canada - EN39. I will be
> going some time towards the end of June or in July. At
> this point I dont know any more details - what dates
> exacty. I should be running 50, 144, and 432.
>
> Douring last years trip I encountered problems raising
> my antennas and was only able to operate on 50 with a
> screwdriver. I was trying to raise the whole
> mast/rotor/antenna array from a horizontal position to
> vertical with the use of a pully system. However, keeping
> the base of the mast stationary and pulling up all that
> weight (even with the mechanical advantage of the pulleys
> - 3 wheels on each one) prooved to be MUCH more difficult
> standing on granite rock 5 feet above the water!!
>
> I am still working on this year's setup. My plan is to
> erect the lower support mast and the upper rotor
> assembly/mast/antennas at the same time on the ground.
> The rotor and antennas will be mounted to a PVC tram that
> will slide up and down the support mast with the use of
> the same pullys as last year. This way, the load is
> strait up and down rather than trying to tilt up the
> whole assembly. The PVC tram will lock into rotational
> position using pins in the top section of the mast. This
> way, the position of the antennas wont change with the
> wind. I plan on just tying down the pully line to
> something (like a cleat on a flagpole) to keep the
> antennas from comming down. Once the tram with the
> antennas and rotor is up then the whole thing can be
> guyed down. In fact, I might just attach the guy lines to
> the tram. For a portable setup it should work OK. As it
> is I am making this pretty complicated!
>
> As of right now I am not quite sure how to erect the
> main support mast. I cant guy it, otherwise the antennas
> will not be able to pass up and down the mast. Right now
> I am planning on making a tripod type thing for the base
> of the mast. The other option would be to strap downt he
> mast to the deck. This might be the best way to go
> because of the top heavy rotor and antennas might knock
> over a tripod (even just in the time it takes to raise
> the antennas). Ill work on the setup in the next couple
> weeks and see what I come up with.
>
> Steve, KC8QVO
>
>
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