# FM transmitter

#### sheraz_ss

Joined Oct 21, 2019
2
Many people have built simple FM transmitters that have problems that I solved when I fixed them:
1) The radio frequency changes when the battery voltage runs down as it is used. So I added a voltage regulator.
2) The radio frequency changes when something moves towards or away from the antenna. So I added an output buffer amplifier to isolate the oscillator from the antenna.
3) The sound is muffled with no high audio frequencies when heard on a normal FM radio. So I added pre-emphasis like all FM radio stations have and it matches the de-emphasis in all FM radios.

Here is the FM transmitter I designed and built and it works well and sounds great:
yes sir, i have this schematic and its works well. and second thing is that i need a receiver circuit for that transmitter for the wireless communication between between the transmitter & receiver. your help will much be appreciated.

#### Audioguru again

Joined Oct 21, 2019
2,875
Problems:
1) The circuit in the first post has high value LC parts so its radio frequency will be very low and a custom-made receiver will be needed to work at that very low RF frequency.
2) The circuit in the first post can be a very simple AM transmitter since it will be very difficult to modulate its radio frequency to produce FM.

Sheraz, are you the same person as Sparkboat who started this thread? Then you changed your e-mail address and needed to register again the same day (a few days ago this website got new software) as me.