The KLM log is rated at 12 sq ft and weighs 100 lbs (7.2-10-30version).
A friend here locally had a similar problem with his G1000 rotor on a
Sommer beam( quite large, has coverage from 7 to 30 mhz) and it failed
very soon in its' career. Well within the wind spec too, but possibly not
within the "flywheel" spec. Why bother to specify a wind area when it's
such a vague spec anyway? Anyway it was full of parts that rattled -
gear parts not ball bearings. He replaced it with a Emotator (not sure
of the number) and it has behaved fine since.
I never seem to hear much about the old Wilson 1000's.....I have one
turning a 3el 40m at 145' (40' boom, weighs over 300 lbs) and it handles
it effortlessly, even in high winds. I had it turning a 4-30 Sabre log
that weighs 1300lbs and it turned it fine but it was only a temporary
situation until I built my own unit (worm drive, etc). The problem there
was the log kept turning and would often go another 90 deg or more before
stopping and I hated to drop the brake on it at full steam like that. But
I did a few times w/no problems but that's too much like gambling. And
-40C weather has no slowing effect either. Wish I had a barn full of
them....
73 Don
VE6JY is Don Moman email: ve6jy@freenet.edmonton.ab.ca
Box 127 Lamont, Alberta
T0B 2R0 (403) 895-2925
On Wed, 7 Aug 1996, Pete Smith wrote:
> At 03:36 PM 8/6/96 -0500, Dave Raymond-CSUS04 wrote:
> > For whatever it's worth, N0AMI (Jim), located here in Des Moines
> > recently replaced his Tailtwister with a G1000SDX rotor. The
> > tailtwister had finally failed after six years of turning the large
> > KLM Log Periodic (with the 40 meter kit). This antenna is on a 42'
> > boom. Ths antenna, however, is well below the maximum wind load
> > specified by Yaesu.
> >
> > We installed the G1000 with high hopes...we all thought the control
> > box was rather nifty but we questioned the very light weight of the
> > rotor itself. Upon the 100th day of operation, the G1000 failed. Jim
> > has a weather station at his qth and had recorded no winds over 50
> > mph. We pulled out the new G1000 and replaced it with a spare
> > Tailtwister. After we got down on the ground, we discovered the
> > problem. When you shook the G1000, it sounded like there were scores
> > of loose pieces inside (probably bearings?). We didn't dare open it
> > up!
> >
> > Sooo, based on that experience, I would think twice about using a
> > G1000 to turn any heavy loads or antennas with long booms.
> >
> > 73,
> >
> > Dave
> > WA0FLS
> >
> > P.S. The spare Tailtwister is still in place and working.
> >
> >
>
> Hi Dave -- Are you sure about that wind area spec? My G-1000SDX book shows
> 2.2 square meters, or about 24 square feet -- I would've thought that KLM
> was bigger. Also, they say in the book - and this seems to me a more
> relevant spec - that the product of the rotating radius and the weight of
> the antenna should not exceed 2020 foot/pounds. On a 43-foot boom, that KLM
> probably weighs more than 100 pounds, no?
>
> When I inquired on the contest and DX reflectors, I found a number of people
> who had G-1000s with quite large loads - I think the biggest was a 40-2CD
> and a Tennadyne 10-element 20-10 meter LP - with no failures reported.
> Could it be you ran into a manufacturing error or a materials problem in
> that particular unit?
> 73, Pete Smith N4ZR
> n4zr@contesting.com
> LOUDER is gooder....
>
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