HI!
I am new to electronics .planning to do fm bug for college project

can someone explain this circuit in detail

 

Hi its',
Welcome to AAC.
Check this AAC link.
E
https://forum.allaboutcircuits.com/...ransmitter-bug-in-ltspice.199271/post-1890180

 

HI!
I am new to electronics .planning to do fm bug for college project

can someone explain this circuit in detail

Hi I,
Welcome to the forum, if you haven't already seen it here's an explanation: https://talkingelectronics.com/projects/Voyager/Voyager-P1.html
Check your licence before transmitting.
C

 

These simple bugs fall into the category of "trickier than it seems"

The way the frequency is modulated is not straightforward, if fact, this produces a carrier that is both AM and FM modulated at the same time.
The audio signal voltages alter the junction capacitances in the transistor, changing both the amplitude and frequency.

 

These simple bugs fall into the category of "trickier than it seems"

The way the frequency is modulated is not straightforward, if fact, this produces a carrier that is both AM and FM modulated at the same time.
The audio signal voltages alter the junction capacitances in the transistor, changing both the amplitude and frequency.

My main doubt here is:
just a 9V power supply and a LC tank will be able to generate a carrier , but what role does the 10pF that connects b/w Emitter and Collector play in FM modulation and signal generation?
Is it still a colpit oscillator?

 

My main doubt here is:
just a 9V power supply and a LC tank will be able to generate a carrier , but what role does the 10pF that connects b/w Emitter and Collector play in FM modulation and signal generation?
Is it still a colpit oscillator?

Are you the same person who started this thread?

 

Are you the same person who started this thread?

Nope ! Bruh...

It seems like someone else is intrested in that same circuit.
It is perfectly fine even if you reply in my thread.

 

Nope ! Bruh...

It seems like someone else is intrested in that same circuit.
It is perfectly fine even if you reply in my thread.

If you had already started your on thread on this subject, why did you even bother to reply here?
It gave the impression that you and the TS were the same person.

 

If you had already started your on thread on this subject, why did you even bother to reply here?
It gave the impression that you and the TS were the same person.

I admit but Not exactly the same person!!
I asked my friend to do it, he is a team mate of mine for this project.Im not sure if its right as im new.
but I appologise, I really thought of closing the previous thread but Dont know how to do that....
coz its dumped with a lot of simulations

 

Hi 2k4,
Whom ever you ask, you will get the same answer.

With that simple circuit, you will always have some level of amplitude modulation in addition to the FM modulation.

It will give satisfactory short range operation.
E

 

I really thought of closing the previous thread but Dont know how to do that.

The original poster can use the Report button at the foot of the post to request a moderator to close the thread.

 

I admit but Not exactly the same person!!
I asked my friend to do it, he is a team mate of mine for this project.Im not sure if its right as im new.
but I appologise, I really thought of closing the previous thread but Dont know how to do that....
coz its dumped with a lot of simulations

There is no need to play games. If you need help with organizing the flow of a thread, just ask a moderator for assistance.
We prefer not to have random threads on the same subject. It makes it confusing for readers to follow. Remember, threads on AAC forums are not just for answering your own questions. Threads can be very useful for other readers who might be having similar problems.

 

Dont know how to do that....
coz its dumped with a lot of simulations

Hi, 2k4.
A small point, your opening post included a LTSpice file of the project.

 

I admit but Not exactly the same person!!
I asked my friend to do it, he is a team mate of mine for this project.Im not sure if its right as im new.
but I appologise, I really thought of closing the previous thread but Dont know how to do that....
coz its dumped with a lot of simulations

If you wish, we can close this thread and continue on the older thread.

 

Fine for me!
Close it.
Ill post that question #6 in the older thread

 

Hi, 2k4.
A small point, your opening post included a LTSpice file of the project.

There is nothing wrong bro I just thought of starting fresh
Sorry for the confusions...

 

This thread is now locked.
Continue the discussion here:
https://forum.allaboutcircuits.com/threads/simulating-a-rf-transmitter-bug-in-ltspice.199271/