hai, guys i am new to this forum , i am working on this project now, plz give any usefull links about local oscilator
thanks in advance

 

Hello,

A local oscillator is basicaly any kind of sinewave oscillator that has a frequency of the wanted frequency + or - the MF frequency.

On this page you will find a lot of oscillators:
http://www.qsl.net/va3iul/Homebrew_RF_Circuit_Design_Ideas/Homebrew_RF_Circuit_Design_Ideas.htm
(look inside the heading "oscillators").

Bertus

 

hello,

a local oscillator is basicaly any kind of sinewave oscillator that has a frequency of the wanted frequency + or - the mf frequency.

On this page you will find a lot of oscillators:
http://www.qsl.net/va3iul/homebrew_rf_circuit_design_ideas/homebrew_rf_circuit_design_ideas.htm
(look inside the heading "oscillators").

Bertus

thakyou sir

 

THIS IS THE CIRCUIT OF LOCAL OSCILATOR, i searched for the function of this, but i didn't find it.so, Plz explian the circuit

 

Hello,

The PDF is of a very bad quality.
I can not read any text.

Bertus

 

Hello,

The PDF is of a very bad quality.
I can not read any text.

Bertus

sir we are actually using crystal and three stages of transistors(( tank circuit at collector terminal) for obtaining the required 389mhz frequency and finally using filter for eliminating or derceasing the
sub harmonics and spurious

 

sir we are actually using crystal and three stages of transistors(( tank circuit at collector terminal) for obtaining the required 389mhz frequency and finally using filter for eliminating or derceasing the
sub harmonics and spurious

You have basically covered all the explanation which could be done looking at that schematic.

I can guess that the original crystal frequency is somewhat lower & is multiplied in the three stages,but whether they are doublers,or triplers or whatever is anyone's guess.

I think it is a drawing of a practical circuit,& it looks as if the capacitance for each resonant circuit is supplied by stray capacitance,as no physical capacitors are shown in the collector circuits.

 

You have basically covered all the explanation which could be done looking at that schematic.

I can guess that the original crystal frequency is somewhat lower & is multiplied in the three stages,but whether they are doublers,or triplers or whatever is anyone's guess.

I think it is a drawing of a practical circuit,& it looks as if the capacitance for each resonant circuit is supplied by stray capacitance,as no physical capacitors are shown in the collector circuits.

yes sir it's a practical circuit and we are designing it

 

Thank you good follow-up

 

A Quick Sine Wave Generator: http://www.ti.com/general/docs/lit/getliterature.tsp?literatureNumber=snoa839&fileType=pdf