Thank you very much for that great info Al.
Im leaning toward a new LM470. Im going to call Karl and ask him a few more
questions today, just as a note I never did get a call back from USTower.
Im not going to be using the tilt up base so that's a non issue.
One last thing Al, is your LM470 motorized and how often do you raise/lower
it and is the operation smooth?
Thank you for the good info, I looked up up on google maps and can see your
monstir, nice setup.
On Tue, Feb 22, 2011 at 7:45 PM, Al Williams <alwilliams@olywa.net> wrote:
> I have had the LM470E for 11 years with the last 5 holding a Steppir Monstr
> a foot or so above the tower and a 2 element Steppir at the top of the 2nd
> section (about 50' when fully extended). There haven't been any tower
> strength problems that I am aware of.
>
> I purchased the tower from a company called Paragon in California with the
> transactions done by another company called First Call. First Call put out
> more than a normal share of BS.
>
> One publication dated 8/27/00 states that since Jan 2000, The Triex series
> towers began using 60000 ksi yield strength steel making them stronger than
> other towers. This publication specified the LM470E as capable of 24 sq ft
> in 70 mph winds. My county required spec at 80 mph winds and Karl reduced
> the rating to 18 sq ft
>
> However when they modified the manual of the LM470 they renamed it to the
> SKY 470 and specified it as being a 68' tower and capable of 16sq ft in 60
> mph winds!
>
> Besides all this one has to be sure that the same ubc standard is used to
> compare the two towers.
>
> I bolted the tilt fixture to the rods buried in the cement and used a plumb
> bob to align it vertical so I doubt
> that getting the tower vertical is a problem.
>
> There are other differences that may effect your decision:
> MY LM470E tilt up apparatus is completely different with the HDX being much
> superior. The HDX472 has two pulley mounts welding to the tower and used two
> pulleys at the top of the tilting fixture with the cable threaded through
> them all giving considerable mechanical advantage over the LM470E which
> instead has
>
> a temporary bracket bolted to the tower which can hold only one pulley. The
> tilt fixture has only one pulley at the top. Once the tower has been tilted
> upright, the temporary bracket and pulley is removed and placed at the
> bottom of the tilt fixture. The tower is then swiveled over and down on
> ears on the top of the tilt fixture. This has an advantage of distributing
> the tower weight on both sides of swivel supposedly making it easier to
> crank over. However the distribution is really upset when the antenna is
> placed way out on the tip of the retracted tower with mast! Plus there is
> little mechanical advantage with the lesser number of pulleys.
>
> I modified my LM470E to have two pulleys on the tower and at the top of the
> tilt fixture so it is identical in practice to the HDX572. It takes a lot
> longer to crank all of that extra cable but is much easier.
>
> If I had to do it all over, I would go with the HDX572 (providing the spec
> is close to the LM470E).
> However I never did install the HDX572 as I have two LM470E and only
> purchased the HDX572 because it was offered for $1100 and was claimed to be
> the HDX589.
>
> k7puc
>
>
>
>
>
>
>
>
>
>
> t
> ----- Original Message ----- From: "damon stewart" <wsmc551@gmail.com>
> To: "Al Williams" <alwilliams@olywa.net>
> Cc: <towertalk@contesting.com>
> Sent: Tuesday, February 22, 2011 3:29 PM
> Subject: Re: [TowerTalk] Tower for a DB36
>
>
> Im not positive but I do belive the HDX572 is a stronger tower. Its hard
>> to
>> compare the two when they don't use the same wind speed and standards. All
>> of the tower sections for the HDX are slightly larger then the LM and the
>> overall weight is several hundred lbs more, that does go a long way.
>>
>> Karl wont discuss any other brand of tower if asked. I still waiting for
>> a
>> call back from USTower.
>>
>> Damon Stewart, KJ7E
>>
>>
>> On Tue, Feb 22, 2011 at 2:41 PM, Al Williams <alwilliams@olywa.net>
>> wrote:
>>
>> Are you sure that the HDX572 "is the next step up?".
>>> I have had both and while the HDX572 looked stronger, with large diameter
>>> tubing, the specs was rated less that the LM470 (according to my memory).
>>> The LM470 tubing was changed a number of years ago to have stronger
>>> strength. Check it out and be sure to compare ratings at identical wind
>>> speeds.
>>>
>>> k7puc
>>>
>>>
>>> ----- Original Message ----- From: "damon stewart" <wsmc551@gmail.com>
>>> To: <towertalk@contesting.com>
>>> Sent: Tuesday, February 22, 2011 1:48 PM
>>> Subject: [TowerTalk] Tower for a DB36
>>>
>>>
>>>
>>> Having a hard time deciding on a proper tower for a Steppir DB36. The
>>>
>>>> LM470
>>>> is with in the budget but I fear it may be just a bit light. Maybe,
>>>> maybe
>>>> not but I would prefer to error on the side of caution especially given
>>>> the
>>>> consequences.
>>>>
>>>> Next up would be the HDX-572 and then the DX70. I KNOW the DX70 would
>>>> have
>>>> no problems at all but its a bit out of my price range. The HDX-572 is
>>>> at
>>>> the upper limit but if the LM470 wont work what choice do I have.
>>>>
>>>>
>>>>
>>> _______________________________________________
>>
>>
>>
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk@contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
>>
>
>
--
Damon Stewart, KJ7E
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