At 16:54 7/10/2008, you wrote:
>Most towers that were designed not to have positive pull down cannot
>be EASILY modified to have the pull down feature. It all comes down
>to the fact that the pull up cable has to wind in at the same rate
>that the pull down cable is letting out and vica-versa.
Bob,
Not completely true. The "however" is you have a manual positive pull
down system.
I agree that you cannot retrofit the same system as on the larger
towers that are designed with a positive system.
Here's what I did. I attached an 7x32 aircraft cable to the bottom of
the top section. I chained a pulley to the bottom of the tower and
ran the cable thru the pulley. I used a cable compression clamp to
grab the aircraft cable and attached that to a come-a-long. Normally
I'd use my tractor as an anchor point but I also used my truck.
I'd first tension the top section with the come-a-long. I would then
lower and tension, lower and tension. I watched to see if the top
tower wire would go slack and if it did, I'd raise the tower,
re-tension and then lower again. Normally, after lowering the tower
1-2' gravity would take over and there was no more need to use the
"positive" system.
The reality is that my W-67 would not come down without the system I
designed. I had a friend at the local fire dept come over and I did
all this work while hooked in to a fire ladder. I would never climb a
crank-up even if it was blocked with 4x4's. Not never ever.
73, Craig Clark, K1QX
RADIOWARE AND RADIO BOOKSTORE
PO BOX 209
RINDGE NH 03461
603 899 6957
WWW.RADIO-WARE.COM
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