Inductor for FM Tx

[bluesky11]

Hi all,

I want to make the below circuit with SMD components so what value of SMD inductor will use in the place of coil.

Thanks in advance



Here is the link

http://freecircuitdiagram.com/2008/10/28/single-transistor-wireless-microphone-fm-transmitter/

[Hero999]

That circuit has, no RF buffer amplifier, so the frequency will drift if objects are placed near the antenna, no voltage regulator, so the frequency will change as the battery runs down and no pre-emphasis so it will sound like an AM radio.

I'd recommend using this circuit which has all of the above and the inductor values are clearly marked.


http://www.silicontronics.com/index.php?action=ezportal;sa=page;p=15

[audioguru]

The inductor values of my FM transmitter were just guesses. The construction of the coils was copied from a project that works and mine also works.

[Hero999]

With the values shown the calculated frequency range is 85MHz to 225MHz. In practise it'll be lower, more like 80MHz to 160MHz.

[bluesky11]

And I want to use very sensitive receiver with one of these above transmitters. My purpose is only voice transmission I dont want musical transmission at that time. I want simplicity at the transmitter side because bettery life is very important at that side but at receiver side I want a most sensitive FM receiver so that it pull in a small signal from far away distance. 

I searched on google and found some super regenerative FM receivers, will they do the job?

or some one know any FM receiver for this purpose.

Any Ideas will be appreciated

Thanks in advance

[bluesky11]

Here is the links of Super regen FM receivers

http://www.tricountyi.net/~randerse/superrgn.htm

In the above link the author says that: "the receiver that is so sensitive it can hear the local oscillator inside a small transistor radio 30 - 50 feet away".

or

http://www.electronics-lab.com/projects/rf/007/

[audioguru]

I think a super-regen FM "radio" is a piece of junk.
It has an AM detector so it must be tuned to one side of an FM station so it can "slope-detect" the FM.
It overloads very easily.

[bluesky11]

I think a super-regen FM "radio" is a piece of junk.
It has an AM detector so it must be tuned to one side of an FM station so it can "slope-detect" the FM.
It overloads very easily.

So which FM receiver is suitable for the above purpose

[Hero999]

A super-hetrodyne receiver.

You can buy one for a fraction of the cost of making one.