It is 1 over 2 pi which is the original formula.  1 over 6.28 is .159
73
Butch
WA0VJR
Node 3148
Wallace, ks.


On 
Tue, 17 Jan 2012, Scott Howell wrote:

> Mike,
>
> I see how this works, but one question is where does the 159 come from? =
> Just curious and hey if it works that is fine by me. Any other tips? =
> grin
> Like I said, math is my weakness and something I have always wanted to =
> understand. I used to be afraid of math which seems pretty silly, but I =
> really find the subject fascinating now and wish I had the same attitude =
> when I was younger. I'm not really sure where I went wrong in my study =
> of math and why I never learn to appreciate the value of subjects like =
> algebra. Probably just did not have the right teachers when I was young =
> and impressionable. grin
>
> 73
> Scott/N3BYY
> On Jan 17, 2012, at 12:20 AM, Mike Cozzolino wrote:
>
>> hello scott, i tried to follow your formula, but the way you wrote it=20=
>
>> i couldn't follow it.  anyway scott, why don't you use the formula >>=20=
>
>> f=3D159 over the square root of l times c <<.  first you multiply the =
> l=20
>> times c and then you get the square root of that answer.  then you=20
>> take the 159 and devide that by your answer.  the answer i got using=20=
>
>> the values you gave, 50 microhenries and 200 pico farads was 1.59.  i=20=
>
>> left the values at their original values picos and=20
>> microhenries.  thats the formula i always use for resonance of a=20
>> tuned circuit.  73 bl c u mike w6quv
>> =20
>> =20
>> =20
>> At 07:06 AM 1/16/2012, you wrote:
>>> All,
>>> =20
>>> Ok, I'm studying away here and trying to master the material for the =
> =3D
>>> Extra class exam. I have to admit that my math skills are not the =
> best, =3D
>>> but in my defense I have not done such fun stuff when in school and =3D=
>
>>> certainly never took much algebra. So, I'm admitting my mathematical  =
> =3D
>>> ignorance  here and asking for a little mercy. grin
>>> I want to understand how best to work out these problems because =3D
>>> remembering the answers is probably almost as much work. grin
>>> So, here is the question and this is dealing with resonance.
>>> The forumla f sub r =3D3D r squared times l squared.
>>> So, f is the resonant frequency and I got that and that is what I =
> need =3D
>>> to solve for.
>>> So, r is 50 micro henrys and l is 200 pico farads.
>>> I understand that I need to convert micro henrys to henrys and pico =3D=
>
>>> farads to farads. I gather multiplying 50 times 10 to minus 6 gets =
> the =3D
>>> job done and doing this on a calculator would be 50 times 10 (press =
> the =3D
>>> x y button) -6.
>>> You would do the same for converting pico farads to farads.
>>> However, at this point I'm not quite sure how to work out the rest =
> and =3D
>>> of course entering this into a scientific calculator is really =
> important =3D
>>> and would make the process a bit easier.
>>> I realize the end result will be an answer that is in megahertz. If =3D=
>
>>> anyone could help with this I would really appreciate it. The =
> electrical =3D
>>> theory portion of the exam is going to be the difficult part for me. =
> =3D
>>> RUles etc. no problem, but this stuff which I'm sure is going to be a =
> =3D
>>> big part of the exam is going to be the make or break for me.
>>> =20
>>> thanks,
>>> 73
>>> Scott/N3BYY=3D
>
>