Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

please help!

Status
Not open for further replies.

julius1723

New Member
I just finished making my 3v fm transmitter but seems there was a problem because the signal are not stable it operates but suddenly the signal receive by the receiver is lost. would you please help me?
 

Attachments

  • untitled_508.jpg
    untitled_508.jpg
    15.4 KB · Views: 598
I am not surprised.

As soon as you put your hand near to this thing, the stray capacitance will change and the frequency will change as a result.

The antenna is connected directly to the circuit which determines the frequency, move the antenna, change its shape or bring another object near to it and the frequency will change.

C4 is not "optional" it is ESSENTIAL.

The circuit is at best a toy, at worst a piece of junk. I am sorry if this sounds harsh, but that is the reality.

JimB
 
julius1723 said:
I just finished making my 3v fm transmitter but seems there was a problem because the signal are not stable it operates but suddenly the signal receive by the receiver is lost. would you please help me?

This is normal for your circuit, simply because the antenna (doesn't matter what kind it is) is literally hogging the frequencies and sucking the signal out of the transmitter.

I think your best bet is to somehow attach a "buffer amplifier" to where the antenna is supposed to go and that might add stability.

Basically, you can have either high stability, or high range, but not both.

see talkingelectronics.com interative website. They have a whole article on transmitters.
 
:)

hey! guys thanks all of youre suggestions ill look this a very big thing that you've contributed to me as a electronics newbie..
 
It doesn't have a voltage regulator so its frequency will change as the battery runs down too.
After all, that's how it makes FM. By the microphone changing the conduction of the transistor, which also changes the voltage across it, therefore changing its collector capacitance that is connected directly to the tuned circuit. :lol:
 
try this it on a site that if u look at the bottom of this page there is a link to it saying that "free electronics circuits" is our friend
https://www.free-electronic-circuits.com/circuits/fm-transmitter.html
try also encasing ur project im a metal box. i had the same problem with something not that different from this: a disaster and 5 minute wonder
 
that sensor is a little too much.

that [bleep] actually meant the word that rhymes with the F-word (swear word), but it starts with S. It's S---U----C-----K.
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top