How can i stabilize LC's frequency?

[holax12]

I notice that my fm transmitter's frequency usually shift with time, how can i make the frequency to be stable with time nd voltage drop.

 

[blueroomelectronics]

Crystal ball broken, what transmitter is that?

 

[marcbarker]

Crystal ball broken, what transmitter is that?

Mine is too.

Let's pick one at random and talk about this instead... Simple Transmitter

The simple transmitters drift because they just do.

 

[holax12]

I meant using inductor&capacitor oscillator as the rf generator.

 

[marcbarker]

I meant using inductor&capacitor oscillator as the rf generator.

PLease tell more Do you mean as an alternative to something?, or do you mean you would like to improve the way inductor / capactor is used?

 

[Nigel Goodwin]

If you're talking about a crude 'bug' there's little you can do, but assuming it's a proper RF signal generator use VERY high quality components, make the coil VERY thick and strong, and build it inside a temperature stabilised totally screened metal box.

 

[mvs sarma]

I notice that my fm transmitter's frequency usually shift with time, how can i make the frequency to be stable with time nd voltage drop.

perhaps, even if you are given ways to stablize, you may not have that level of Lab quality test instruments that could measure the stability aspect. In principle, we cant stabilize any oscillator just by normal means.
the best for you would be to go for a standard reference oscillators that are sold . they are periodically calibrated with rubidium standard clocks. Of course they cost a moon.

the normal means of stabilization would definitely distort one or the other parameters.

we can't just have calibrated quality, voltage, resistor, capacitor, inductor , nothing. it is a profession by itself and costs.

please try to realize what you are asking for.

 

[trennonix]

Mine is too.

Let's pick one at random and talk about this instead... Simple Transmitter

The simple transmitters drift because they just do.

that transmitter you posted, is it good? it looks real simple, almost too good to be true.
And if it is, can i switch the transistor with a bigger one and up the voltage so that i get more power?

 

[marcbarker]

that transmitter you posted, is it good? it looks real simple, almost too good to be true.

I believe holax12 has practical experience of it that he might want to share