[TowerTalk] MA-550 advice...

[Jim Jarvis]

Steve,

I had a 40 footer up for some time, in New Jersey.

It was the world's biggest wind chime, when in the
nested position.  Not only did the tubes clank together
in wind gusts, there was slight rotation when the wind
clocked.  The result was a banshee howl/grinding noise.

The tower in question was house bracketed, and the sound
coupled into the frame of the house...right outside my
bedroom, of course.

Free standing is probably better, from that perspective.

Jim/n2ea

-----Original Message-----
From: K7LXC at aol.com [mailto:K7LXC at aol.com]
Sent: Tuesday, August 19, 2003 02:37
To: David at giuliani.org; jimjarvis at comcast.net
Cc: towertalk at contesting.com
Subject: Re: [TowerTalk] MA-550 advice...


In a message dated 8/18/03 8:41:05 AM Pacific Daylight Time,
David at giuliani.org writes:

> I'm now on your page after strugging with alternatives.  For my QTH,
>  the MA-550 seems perfect -- neighbor and code friendly in terms of
>  appearance and ability to lower it below the roofline of the house, easy
to
>  install assuming I can work on its top side from the second story roof.

    Sounds great. And they're aesthetically pleasing - they just look like a
big flagpole.
>
>  Sure could use your experience now that I'm running on this track.  E.g.:
>  Hadn't even thought of sound deadening as an issue.
>
    Sound deadening? You mean the tower crank-up mechanism? The motor just
whirs and once in awhile a cable creaks. Barely discernible even when you're
very close to it.

>  Situatin: I'm assuming I'll use a MAB or MARB base.  Antenna will be a
Force
>  12 3CSS weighing 25#, and a 2 meter yagi and 2m/0.70m vertical above it,
and
>  some kind of nice rotor; a bottom mounted would certainly look nicer and
be
>  a lot less hassle to maintain.  I'm in my mid-50's and in excellent
shape,
>  but that may not always be the case in the future....  $ is an issue, of
>  course, but I want to make sure I'm not pennywise and # foolish.
>
>  Questions:
>
>  1.  Is is practical to use the MARB rotator base and still attach the
unit
>  to the roof?

    Well, if you use the rotating base then the whole tower rotates so
you'll
have to have some sort of floating bracket on the house.

    But you don't need it. The tower is designed to be self-supporting.
Don't
mess around with any "vest pocket engineering".

>  Is there an available bearing?

    No. See reply above.

>  2.  If I don't attach to roof, does the 3.5' x 3.5' x 5' concrete pier
still
>  provide sufficient stability?

    What do your factory plans say? What do your PE plans say? Don't
second-guess the manufacturer. In all cases follow the LXC Prime Directive
to "DO what
the manufacturer says." This also covers the house-mounted bracket. Do they
offer one? Do they specify using one?

>  3.  Raising lowering - do I need the MAF if I can use the roof structure
>  itself and a block and tackle?

    No, but don't underestimate the weight and force of the tower. It's
HEAVY.

>  4.  Motorizing the up and down...hand crank vs motor?

    The whole tower only weighs 435 pounds with a bunch of it in the bottom
non-moving section. You could hand crank it but you wouldn't want to do it
everyday.

>        buying the MD-75 or MD750 vs rigging a lower cost motor later?

    Installing the motor drive later is not a job for an amateur. You
probably don't have enough cable when you convert from a hand crank and
there are
other issues; i.e. it should be done while the tower is horizontal.

    I spent a couple of days at the factory learning how to cable their
crank-ups and what I found out was that it ain't easy!

>  5.  Noise management

    What noise?

Cheers,
Steve     K7LXC
TOWER TECH -
Authorized US Tower installer