FM transmitter question

[zachtheterrible]

I have built these two circuits on a breadboard and tested them with an RF probe, which works great by the way, and have gotten absoulely NO results. Just wondering if someone could analyze these circuits and tell me if I'm just doing something stupid, or if it has something to do with the breadboard (I wouldn't imagine so, but u never know), or there is actually a flaw in both of these circuits.

 

[Nigel Goodwin]

Just wondering if someone could analyze these circuits and tell me if I'm just doing something stupid, or if it has something to do with the breadboard (I wouldn't imagine so, but u never know), or there is actually a flaw in both of these circuits.

You can't use breadboards to build VHF RF circuits, the capacitance of the board is far too high - I wouldn't expect it to work.

 

[zachtheterrible]

WOW!! I never thought that that would actually be true. Do you have any good ideas for testing VHF circuit w/o a breadboard? I thought of clipping all of the leads together w/ some aligator clips, but would the long uncut leads mean that the capacitance would again be too high?

 

[Prototypn45]

what do ya mean by sayin that the capacitance of the breadboard is too high???

 

[andrew2022]

i have also tried to make both circuits before (on breadboard) and it didnt work

 

[Nigel Goodwin]

what do ya mean by sayin that the capacitance of the breadboard is too high???

The adjacent tracks have a fairly high capacitance between them, you can't build VHF radio circuits on something like that.

Remember, a capacitor is two conductors, seperated by an insulator - sounds just like a breadboard!.

 

[Prototypn45]

Oh yah. I forgot about that. Thanks!!!