Making an FM Transmitter

Hi Vincent,

You can use a BC547 or a 2N2222 or similar for the transistor.
For the inductor 6.8µH will be to high, the BOM state 0.1µH, you can easily made the inductor yourself with a piece of rigid electrical wire of around 1mm of diameter

Olivier

 

it will not be practical to use paralleled 6.8uH inductors. Really it's easy to made one with a piece of laying around rigid wire turned on a 5-6mm drill bit. If you want a ready made solution you can order a free inductor sample at coilcraft.com

http://coilcraft.com/forms/files/en...essionid=8430da0eb31cb4322fa7181a165667227214

Olivier

 

That's it single core wire, like this:

http://dgysdx.en.alibaba.com/produc...ower_Wire_PVC_Insulation_Electrical_Wire.html

Olivier

 

PS as the wire is unvarnished stretch the inductor a bit

 

It must look like this

http://www.w0qe.com/Technical_Topics/images/1uH_10yr_outside_wire-hi.jpg

Olivier

 

You're not going to be supporting a high rise with it. Trench soldiers worked with much less.

Chris

 

Yes you can use a 2N3904

 

Did you read the description in your link?

Chris

 

The odds are that you don't posses a frequency counter, grid or gate dip meter or a scope capable of measuring this. This leaves you with what you have, which is the FM receiver itself.

Chris

 

Well this is a very basic circuit, for best stability use a NPO type capacitor for C4 and build the circuit above a ground plane are probably the only possible improvement. For better stability you need a crystal or a PLL.

For longer range you can locate the transmitter in a higher position and/or use a good antenna.

Olivier