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Can i get a replacement of this transistor ? Answered

i was just messing with circuits and i found this one above in the image i really want to make this but i don't have a BF494 transistor so my question is : Is it possible to replace this transistor with any other transistor if possible please name all possible replacement you know!


Check the Ft of the BF494 (200Mhz) and match it with what you can get locally. The BT494 is a pretty damned fast little transistor, so be careful.

Thanks for your help but tell me what Ft stands for ? (Beause i am not well known to electronics!)

Ft stands for "transition frequency", and is a measure of the kind of frequencies you can expect the transistor to work at
Its a parameter on the datasheet for the transistor. Look for "High frequency" transistors.

The BC109 might be OK for you here.

if i have bc 107 transistor which have different characterstic of bf494 so what change we have eo in circuit

2N3904 or 2N2222 might do you but a 2N3707 is identical to a BF494.

You can get the datasheets here:


You can get the datasheets and the parts for less than Radio Shack here:


Mouser has a great search filter that enables you to put the parameters of a component in and it will tell you all the parts that fit.

This looks like an am receiver with fixed regeneration. if so you can use any npn "popcorn" transistor. Common examples include 2n2222 or 2n3904.


2 years ago

doest tl494 replace bf494

hi, what is the replacement for B1453 transistor

2SC5880 from farnell will do your job. Because you need a low Ft , so i am guessing it is for some high voltage switching (60).

Hello , i dont have a 2N2222, so is it possibloe to replace this transistor with any other transistor is possible

Yes, for general purpose circuit BC 547 or BC 548 or bc 557 work pretty same !

Though you can show me the circuit i will tell you what to do!

I use BC 457 AND 458 -- NPN --- virtually the same
BC transistors are quite common ---
2n2222 have slight voltage difference ---
look up in your tables ---its all there

Hello , i dont have a 2N2222, so is it possibloe to replace this transistor with any other transistor is possible


5 years ago

The physical placement of the RF ( Radio Frequency ) components is CRITICAL
So is the length  of the antenna and the diameter of the four turns..

If you have a pic of this working Follow it exactly.