Thank you Chip ,
For responding to my plight regarding the
destruction of a G-800 rotor .
Your comments with reference to taking the "K" Factor into consideration
has now come very apparent to me after reading page 8 of the G-800
instruction manual which states ,I quote .
"In addition to antenna wind loading and regardless of the type of
installation , the overall size and weight of the antenna be considered .
As a general rule for the G-800SDX ,the product of the rotating radius
and the weight of the antenna should not exceed 180kg-m(1299 ft-lbs),and
for the G-1000/SDX ,230kg-m (2020 ft-lbs). Unquote .
My concern is that at the time of purchase of the rotor from a authorized
YAESU dealer it was clearly explained the make and size of the single mono
band antenna which a rotor was required . (HAM-PRO H240-4)
The only concern the dealers representative had was the, total wind serf
ace area of the antenna, which is 8.27 sq ft. He then advised that as the
G-800 had a maximum antenna surface area limit of 2m sq( 21 sq ft) and
would be more than adequate to safely handle the antenna in question .
At no time was any reference to the maximum "K" factor requirements which
had it been I would have selected the G-1000 series .
Referring to the YAESU Antenna rotor specification brochure it is noted
that NO reference is made what so ever to "K" factor considerations for
any of the published rotors offered .
As this is such a vital specification to be entertained when selecting a
rotor I feel that as such it should be published in the basic specs. not
as it is at the present ,part of the installation instructions provided in
the instruction manual provided with the rotor once purchased . (See page
8 Rotator Installation ,manual for the G-800 /G-1000 series ) In addition
all dealers selling antenna rotors should brief prospective purchasers of
the important criteria of the "K" factor.
Through the fact that I only found this factor out when it was all to
late (Total loss of a G-800 ) rotor which requires a replacement by the
next higher rated rotor ie G-1000 at a cost that I as a pensioner on a
limited income can ill afford .
In summery ,I would like to thank Chip Margelli K7JA for bringing the
facts to my notice ,but at the same time I would suggest that , one , the
advertisement specifications of all rotors include the "K" factor
requirements and two, that YAESU advise all dealers that they instruct
there staff to bring this important factor to customers notice.
Lastly , I would recommend that all present users of this series of
rotors calculate the "K" factor of the antenna(s) you are using and
make sure you are within the specified limits .Don't learn the hard way
like I did)
Mike Holley
<e mail <mholley@quik.com>
Charles Margelli wrote:
> Mr. Holley:
>
> Per the Instruction Manual for the G-800, the maximum K-Factor (in the
> section on "Installation") is the product of the turning radius times
> the weight.
>
> For your antenna, this is 24.4 X 69 = 1683.6 ft-lbs. Since the max
> specified for the G-800 is 1299 ft-lbs, it is not surprising that the
> rotator failed: it is overloaded by about 30-some percent.
>
> Kind regards,
>
> YAESU U.S.A.
> Chip Margelli, K7JA
> <yaesu@worldnet.att.net>
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