You have no DC path for the emitter current.

I change now, is[ this circuit like in complete fm receiver(wich i dont understand), what is this , i just change C3 and L1 i get desired resonance? is here any mistake

 

Just because it is common collector doesn't necessarily mean that the collector is grounded.

Yeah, I know. Was just trying to keep it simple.

 

Your simulation missed out C23, 300pF between emitter and base.
The input coupling capacitor in the original is 5pF.
There should be no resistor across the tuned circuit.
Notice that it will take a while for the amplitude of oscillation to build up - 500us ish.

 

L1 and C3 resonate at 6.5MHz - a long way from VHF.

 

is this correct Albert? and where is that resistor to the tuning? also this from the fm receiver..

 

Try this one. simulate between 1.7ms and 1.701ms but be patient, it takes a while to plot. You can see that the two frequencies have mixed.

 

In the #14 post those curves are for a notch filter.
Top curve is magnitude freq response, bottom
graph phase response.

Regards, Dana.

 

Where did this design (schematic in post #1) come from?

 

Try this one. simulate between 1.7ms and 1.701ms but be patient, it takes a while to plot. You can see that the two frequencies have mixed.
View attachment 162739

Goodmorning Albert, yes i see man, perfect, so this is the correct circuit right?, but one question the tank circuit must be resonance at 110.7mghz, of 10.7mghz

 

Where did this design (schematic in post #1) come from?

Hello Ylli, i take from the book, i did not design, but only the things wich i dont understand i put it here
here the link
n0gsg.com/ecfp/first-edition.htm chapter 9 fm receiver.....

 

In the #14 post those curves are for a notch filter.
Top curve is magnitude freq response, bottom
graph phase response.

Regards, Dana.

Thank you Dana

 

Goodmorning Albert, yes i see man, perfect, so this is the correct circuit right?, but one question the tank circuit must be resonance at 110.7mghz, of 10.7mghz

A circuit which works is the correct circuit.
A super-heterodyne radio receiver works by having a local oscillator some fixed frequency away from (above or below, doesn't matter which) the intended receive frequency. When this oscillator signal is mixed with the incoming signal it produces (among other things) a fixed frequency intermediate frequency (IF). For VHF FM reception this IF is commonly at 10.7MHz so this must be the difference between the oscillator frequency and the received RF frequency.
Note that the original circuit has a fixed tuned transformer in the collector of the transistor. This is tuned to the IF frequency and passes on signals at the IF while rejecting the other signals at the output of the mixer.

 

A circuit which works is the correct circuit.
A super-heterodyne radio receiver works by having a local oscillator some fixed frequency away from (above or below, doesn't matter which) the intended receive frequency. When this oscillator signal is mixed with the incoming signal it produces (among other things) a fixed frequency intermediate frequency (IF). For VHF FM reception this IF is commonly at 10.7MHz so this must be the difference between the oscillator frequency and the received RF frequency.
Note that the original circuit has a fixed tuned transformer in the collector of the transistor. This is tuned to the IF frequency and passes on signals at the IF while rejecting the other signals at the output of the mixer.

So your circuits is working not mine, i download your circuits
Thank you very much man...……..

 

In the #14 post those curves are for a notch filter.
Top curve is magnitude freq response, bottom
graph phase response.

Regards, Dana.

Goodmorning Dana is this graph in orde i make for 88-108mghz
lookView attachment 162803

 

Hello,

Look for "notch filter".
A notch filter can be a parallel resonance circuit in series with the signal path or a series resonance circuit accross the signal path.

Bertus

Goodmorning Bertus, i find notch filter so i design, but For RF L2 and the combination C22 and C17A are making a parallel resonance circuit.
but i dont understand wich frequency so i can chose L2, of frequency from 88-108mghz? MIDDLE BAND 98MHZ

 

 

Hello,

Where did you get the schematic in the first place?
Is there no more information to find?
There are some values missing from the schematic.

Bertus

 

Hello,

Where did you get the schematic in the first place?
Is there no more information to find?
There are some values missing from the schematic.

Bertus

He got it here: http://n0gsg.com/ecfp/ch9_sample.pdf , last couple of pages. But it's only a preview and stops in the middle of the description of the receiver.

 

Hello,

Where did you get the schematic in the first place?
Is there no more information to find?
There are some values missing from the schematic.

Bertus

Hi, Bertus
i get from here
n0gsg.com/ecfp/first-edition.htm
chapter 9 fm receiver.....
but there are not so much information
Goodnight...

 

He got it here: http://n0gsg.com/ecfp/ch9_sample.pdf , last couple of pages. But it's only a preview and stops in the middle of the description of the receiver.

Yes i know, what do you think, they explain if i buy the book all in details,...…...i dont know to buy of not, they explain everythink of not,
i realy dont know, if they explain i gonna order it tomorow…..
OOOwwwww i thought is complete chapter
Goodnight….