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Subject:
From:
Mike Keithley <[log in to unmask]>
Reply To:
For blind ham radio operators <[log in to unmask]>
Date:
Tue, 24 Jan 2012 15:15:04 -0800
Content-Type:
text/plain
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text/plain (104 lines)
It helps a lot, thank you.

----- Original Message -----
From: Howard, W A 9 Y B W <[log in to unmask]>
To:  [log in to unmask]
Date: Saturday, Jan 21, 2012 05:01:00
Subject: Re: Math Help

>
>
> Mike,
> 
> You can enter the scientific notation in the Windows calculator as follows:
> 
> 1.  From the view menu select "Scientific"
> 2.  Press the "X" key, this allows you to enter a number in scientific 
> notation.
> 3.  To enter a negative power of 10, change the sign with the "F9" key prior 
> to entering the power.
> 
> So for example if you wanted to enter 50 micro henrys, you would enter the 
> following sequence:
> 
> "50" "X" "F9" "6"
> 
> The display on your calculator would show the following:
> 
> "50.E-6"
> 
> To take the square root of the L multiplied by C do the following:
> 
> 1.  Using the JAWS cursor, navigate to a button labeled "INV" near the top 
> of the calculator in the row above the 7 8 9 and do a left mouse click. 
> This button does an inverse function on the next key press and only remains 
> on for the key pressed immediately following the press of the "INV" button.
> 
> 2.  Navigate down the calculator keyboard with the JAWS cursor and locate a 
> button labeled "X^2" and left click on this button and you will have taken 
> the    square root of the number in the display.  The "X^2" is in the bottom 
> row of buttons.  The "X^2" button squares a number if not proceeded by the 
> press of the "INV" button first.
> 
> Try this square root function on several numbers that you know the square 
> root of such as 100, 81, 64, 16, or 4 so you know you are doing it 
> correctly.
> 
> I hope this helps.
> 
> 73's
> 
> Howard #3, W A 9 Y B W
> 
> ----- Original Message ----- 
> From: "Mike Keithley" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Friday, January 20, 2012 9:45 PM
> Subject: Re: Math Help
> 
> 
> > This sounds right, but  I know that trying to enter this into a speech 
> > calculator I have is impossible because it won't accept scientific 
> > notation. And I couldn't figure out how to do it in the windows calculator 
> > either.
> >
> > ----- Original Message -----
> > From: David thurmond <[log in to unmask]>
> > To:  [log in to unmask]
> > Date: Wednesday, Jan 18, 2012 05:29:31
> > Subject: Math Help
> >
> >>
> >>
> >> All,
> >>
> >> Sorry for my previous post, I previously stated that 1 picofarad = 1 x
> >> 10 ^ -9 Farad, which is why my calculation was wrong.  I also screwed
> >> up entering the units on the calculator, so I should have
> >> double-checked my work!  I believe this is correct, however:
> >>
> >> The formula is:
> >>
> >> Resonant Frequency (Hz) = 1 / (2pi * sqrt(L C)
> >>
> >> where L is in Henries and C is in Farads.  So, in your example:
> >>
> >> 1.  Convert 50 microHenries to Henries, 1 microHenry = 1 x 10^-6
> >> Henries, so 50 microHenries = 5.0 x 10^-5 Henries.
> >> 2.  Convert 200 picofarads to Farads.  1 picofarad = 1 x 10^-12 farads,
> >> so 200 picofarads = 2 x 10 ^ -10 Farads.
> >> 3.  Now, plug into the formula:
> >> F = 1 / (2pi * sqrt (5 x 10^-5 times 2 x 10 ^ -10)
> >> = 1 / 2pi * 1 x 10^-7
> >> =1591557 Hz
> >>
> >> Hopefully this is correct now, and hopefully I did more than just
> >> muddy up the waters beyond all hope!  My apologies!
> >>
> >> So you can see, the worst part of this problem is getting the units
> >> correct, at least for me.
> >>
> >> 73,
> >>
> >> David Thurmond, KK4ADV 

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