I like the idea of a rotating tower.
Question, with the rotating rings installed does that impede climbing
the tower much?
I'm about to start digging the holes for my 45g tower. A rotating tower
would be nice for stacking.
Rich - N5ZC
On 8/19/2011 8:47 AM, Art K6XT wrote:
> Pete
> Someone else replied about K4JA's loss saying it was a hurricane. Our
> winds don't get up there or haven't yet.
>
> An elephant gun to Asia would be good. I'm trying to avoid a mast and
> associated hardware in the tower. Another piece of R45 above the top
> guys, at 75 lb, seems as light as anything else I could put up there.
>
> The small 20 above the 40 gives me the opportunity for 3 phased 20's.
> Someone suggested a 204BA, I have some of those elements but would
> probably make it a 3L.
>
> My 3L40 is an old DXE. From the factory it came with (what I consider)
> huge tips. Starts out at 2 inch, ends in telescoping tubing at 0.875in.
> To me that is gross overkill at the tips. I replaced the outer 16 feet
> with 204BA elements to cut the weight but more important the wind load.
> My neighbor K0YW has a duplicate of this ant. His element sag is
> something like 3X mine. This ant is up on a hilltop 70 ft crankup
> cranked down to about 50 ft for the past year with no probs so far.
>
> Gotta wonder if K4JA's pair of 40's started twisting in opposite
> directions. AB105 is stout stuff, I had some up 30 yrs ago in San Diego
> area.
>
> 73 Art K6XT
> Allison, Colorado
> "One of the harshest lessons learned from recent disasters, especially
> Katrina, is that you are your own first responder."
> ...LtGen Russel Honore USA
> GMCC CWOps 728
> NAQCC 1342 SDDXC
> ARRL TA
>
>
>
>
> On 2011-08-19 05:54, Pete Smith wrote:
>> You're right to be concerned about twisting loads. K4JA, who is a
>> pretty good back-yard engineer, lost a 200-foot AB-105 rotating tower
>> with 2 40m OWAs on it in a windstorm, and from the debris it was
>> obvious that it had twisted to failure. Afterward, he told me he sure
>> wished he had a shear pin or other provision for breaking the
>> connection between his rotator and the tower, because if it had been
>> free to move it might well have survived.
>>
>> By the way, if you plan to phase the two 3L 20m yagis, wouldn't you be
>> better off putting the top one at 100 feet? Or are you looking for an
>> elephant gun to Asia?
>>
>> 73, Pete N4ZR
>>
>> The World Contest Station Database, updated daily at
>> www.conteststations.com
>> The Reverse Beacon Network at http://reversebeacon.net, blog at
>> reversebeacon.blogspot.com,
>> spots at telnet.reversebeacon.net, port 7000
>>
>>
>>
>> On 8/18/2011 8:51 PM, Art K6XT wrote:
>>> I've started construction of a 150 ft Rohn 45 rotating tower using K0XG
>>> base and four rings, top ring at 140 ft. Just above the top ring will be
>>> a 3L40 and possibly a small 20 above that, like 3L.
>>>
>>> I'd be very interested in any experience or anecdotes on projects like
>>> this using R45. That tower was selected because I already own it. My
>>> area has the potential for icing. The ice I've seen is very light,
>>> nothing like back east or in EU. But I suppose its possible. Not too
>>> windy, the strongest seem to peak out around 70mph and that's rare.
>>>
>>> One issue I see is, there are no torque bars on the tower. All its
>>> torque is transmitted to the rotator on the ground. K0XG's rings do have
>>> torque bars but that doesn't help the tower.
>>>
>>> The general plot is to add antennas down the tower above the guy rings.
>>> Second 3L20, a shorty 40 Hygain, 10 and 15M.
>>>
>>> Replies to k6xt at arrl dot net are FB, or here.
>>>
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