is it ok to use 2n2222 transisitor in a basic FM circuit tx?

[rkgwapo]

is it ok to use 2n2222 transisitor in a basic FM circuit transmitter that is found in google. example is this (theres many in the web that looks like this in the web) https://indianengineer.wordpress.com/2009/10/05/long-range-fm-transmitter-1..

i also have a follow up question. out of the hundred transistor ic out there, how do you determine which one is suited for an Fm application.

 

[IanP]

Re: is it ok to use 2n2222 transisitor in a basic FM circuit

While choosing a transistor for RF application look at: Ft, Noise and Hfe ..
Also read section on: "understanding RF transistor data sheets"
**broken link removed**
..page 114 ..

 

[rkgwapo]

Re: is it ok to use 2n2222 transisitor in a basic FM circuit

thank you for the reply. ill be reading that book now.

 

[nikhilele]

i wont recommend 2n2222

 

[gowthams001]

Re: is it ok to use 2n2222 transisitor in a basic FM circuit

is it ok to use 2n3904? which other model is suitable for transmitting in the range of 100Mhz

 

[Audioguru]

Do they still use a piezo mic in India? I haven't seen one for about 45 years. An inexpensive biased electret mic should be used instead.

My FM transmitter circuit uses a 2N3904 transistor as its oscillator and another as its RF amp that isolates the antenna from the oscillator so that the frequency doesn't change when something moves toward and away from the antenna because it changed the capacitance of the tuned circuit of the oscillator without the RF amp.
It uses a voltage regulator so that the oscillator frequency does not change as the battery voltage runs down and so that the preamp transistor (also a 2N3904) is not saturated and not cutoff and has plenty of gain.
The regulator is a low-dropout type so that a normal 9V alkaline battery can drop to 5.5V and the circuit does not notice except the power is reduced.
Pre-emphasis (like all FM radio stations have) is applied to the preamp so audio sounds perfect and not muffled.
Its range is more than 2km or across the street depending on the sensitivity of the FM receiver.