Quick designing of AM transmitter, Understanding

[Eshal]

Here is what I have done so far.
@goldsmith


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I copies your diagram in order to create mine. I ain't any experienced person, I don't know what design should be, I don't know how many capacitors, inductors or resistors are used here.

 

[goldsmith]

Hi Eshal
Why C2 is in series with potentiometer ? i think with rules that i told you you can calculate value of feed back capacitor and then tank circuit . at least , isn't it ?

 

[Eshal]

You told me Capacitor=0.5C of tank. Right?

So tank=L1/C1. Right?

 

[goldsmith]

So tank=L1/C1. Right?

Yes Tank circuit consists L1 and C1

 

[Eshal]

Here is my value for L1/C1

It is very large.
It must be wrong.

 

[goldsmith]

A rule : you can select one of the L or C randomly and then formula will given you the vague element . for example for C you can start with 100 nf or less or higher ( for 100 KHZ you'd better to select it higher )

 

[Eshal]

No no no no....

I am not getting. I raise a white flag.
I am not getting :-(

 

[goldsmith]

You can't get what ?

No no no no....

I am not getting. I raise a white flag.
I am not getting

An advise : don't lose your hope ! you shouldn't be weak instead of each thing !

See below :

 

[Eshal]

Yes I know I shouldn't lose hope, but I don't know anything practically, I hate our university teachers but I love my field..


L=0.011mH

Is it correct?

 

[tony_lth]

Hi,

f=1/(2*Pi*SQRT(L*C)), your equation is wrong.

 

[goldsmith]

Yes I know I shouldn't lose hope, but I don't know anything practically, I hate our university teachers but I love my field..

I love my filed too , but my university didn't do anything for me too ! unless dissipating my time ! you should learn to learn yourself ! ( and with asking and searching ! )

L=0.011mH

Is it correct?

or as a matter of fact 11 uH ! that's correct ! congratulations . so now , what will be the value of feed back capacitor ?

 

[Eshal]

what will be the value of feed back capacitor ?

We chose 220nF. Should we calculate it again?

 

[goldsmith]

i didn't talk regarding value of tank capacitor ! i talked about fed capacitor ! forgot it ? that law ?

 

[Eshal]

Law? recall.... :-s

 

[goldsmith]

see post #3 you have told it again !

 

[Eshal]

Should it be 0.0121pF?

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C=0.5(11u*220n)
C=1.21pF

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C=1.21pF it is correct one.

 

[goldsmith]

what ????? how you have calculated that value ?

Should it be 0.0121pF?

??????!!!!!!!!!

 

[Eshal]

It should be 1.21pF

 

[goldsmith]

It should be 1.21pF

Eshal , open your mind ! ( a best friend of mine , using this sentence when i telling a thing false ! ) :wink:
Tank capacitor is 220 nf ! so it's half will be 110nf . is that hard ?

 

[Eshal]

Lol... Your friend is right.. Half of the tank capacitor.. aaaggggghhhhh......

In post#1. C3 is feedback capacitor?