[C320-list] Math problem

[LOCALJG at aol.com]

Survey said:  "22 degrees!"
 
Thanks Stan, Irv and Bryan.  
 
Yes Stan, the manual addresses the blanking of the main mast or any part of 
 the superstructure in detail.  The blanking allows the radar to halt the  
sending of a signal while the radar is pointed at some part of the ship that 
the  radar can't penetrate.  As I figure it, the radar  signal being 
bounced right back into the radar unit from so close up  would or could cause some 
type of problem or interference?  But hey, what  do I know, I can't even 
figure out a simple math problem?  
 
Thanks again guys, I appreciate your assistance. 
 
John G. 
1996/ #329
 
 
In a message dated 1/20/2011 1:02:09 P.M. Pacific Standard Time,  
ola7442000 at gmail.com writes:

I  believe the blanked section would be 169 to 191 degrees based on  an
included angle of 21.865 (22) degrees.  I'm curious why you would  bother
with this.  Does the manual recommend it?  If so,  why?

Stan
"Our Little Amusement" #744

On Thu, Jan 20, 2011 at  9:14 AM, Bryan Campbell <bcampbell at valp.net> wrote:

> Based on  Irv's calculations (23 degrees) your blanking are would be 157 
to
> 203  degrees assuming that dead ahead/the bow is 0/360 degrees.
> Cheers,  Bryan
> #627
>
> -----Original Message-----
> From:  c320-list-bounces at lists.catalina320.com
>   [mailto:c320-list-bounces at lists.catalina320.com]On Behalf Of Irving
>  Grunes
> Sent: Wednesday, January 19, 2011 5:08 PM
> To:  C320-List at catalina320.com
> Subject: Re: [C320-list] Math  problem
>
>
> John.
> Its calculates to a little more  than 22 Degrees.
> I dropped a perpendicular from the angle between the  14.5 degree legs to
> the
> 5.5 leg making a right triangle of  Hypotenuse 14.5 and the 2.75 adjacent
> side. Using cosine that angle is  is a little less than 79 degrees
> subtracted
> from 90 degrees is  a little more than 11 degrees.
> Times two because we bisected the  angle, then the blanking area is a 
little
> more than 22  degrees.
> i was too lazy to do the interpolations, so use 23  degrees.
> Irv Grunes
> #851
>
> On Wed, Jan 19, 2011  at 3:16 PM, <LOCALJG at aol.com> wrote:
>
> > I am about to  hang a Furuno Radar dish on my mast.  There is a  way to
>  turn
> > off the radar where the radar signal sweeps past the   mast. This small
> part
> > of the radar's sweeping arch is  called the "blanking  area."    So in
> order
>  > to find the amount of blanking area, I need  to do a math  problem.
> > Regrettably I am mathematically challenged and   wish to gain assistance
> > from
> > someone more inclined  toward numerical  dexterity.
> >
> > Here is the  challenge:  Think of this as a simple triangular  equation.
>  > Two legs of the triangle are 14.5 inches long.  The  base of  the 
triangle
> > is
> > 5.5 inches long.  I need to  know the angle  in degrees of the apex of 
the
> >  triangle.
> >
> > The 14.5 inch legs are being measured from  the center of the  Radar 
dish
> to
> > the sides of the  main mast.  The distance of 5.5 inches  is the 
distance
> >  between the two 14.5 inch legs of the triangle at the  mast.   The
> blanking
> > area of the radar will be around 6 degrees.  I will set  this in the 
radar
> > when
> > I program it  following installation.
> >
> > Thanks for the help.
>  >
> > John G.
> > 1996 #329
>  >
>
>


-- 
Stan
"Our Little  Amusement"
C320  #744
N 36 01' 33"
W 114 46'  08"
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