the transistor is the only piece thats hard to find, uk doesnt sell npn 2n3564 on any bloody website but maybe one in america does, their are equivelents but you want to ask a pro.
(i found the transistor on ebay but its 2.50 plus postage, make one play with it sell it then if you happy get you dad to invest in buying you ten transistors, no one will invest till you have sold at least one unit, you can pull scrap electronics apart you will come across a handfull eventually)
the link tells you how to build it, the code numbers are the part numbers, (L1 is a coil click on the breadboard link on the link they go into some more detail)
the circuit is easy to make cheap to make qont take you long but you can sell it for three times the cost to make, thats the standard profit margin you want for everything, barring jewelry.
this will work but only for pocket money which is perfect for you
its a messy noise with the wrong transistor, maybe it just doesnt work, you want a low voltage npn transistor look up the schematics of the 2n3564 ything has all the components you want in them, learn how to read the values of the components on youtube
scrap crap radios that dont work, battery ones and mains ones alike, everything electronic has the components you want in them, this circuit is easy to make and easy to sell
theres nothing illegal with selling the little bugs just don't violate anyones privacy, your selling them remember, I suggested them because they are fun and so people will like them and they are easy to make and you can sell them for 20$ a piece, once you can make them tidily that is, your dad should help, thats perfect, if your focused you could make a small fortune.
where do you think I can get a microphone?
like what toys can I find them in?
After I make around $50 (Around 32.85 pounds), would you recommend for me to invest into more?
http://www.lucidscience.com/pro-basic%20spy%20transmitter-5.aspx is what I'm currently following, I'm going to use tape or a hot glue gun in an alternative to soldering, (I have to wait till my dad allows me to use his iron, he taught me how to but he doesn't like anyone in his shop and thinks I'll torchure my brothers or something.) What would you recommend as an alternatice?
I'm not getting my hopes up because it will probably be a bust. However if I do sell these do you think if i sabotage the radios to make money off of repairs it'd keep making money?
do whatever to make practice ones, i recommend breadboard if its there, theres no point selling the ones you havnt soldered though, wait till your dad lets you use his iron, your schematic has more parts than mine, that means more work less profit, do whatever but my schematic is a bit more elegant, but yeh theres plenty of them.
make 1 first and sell it, or if you get attached, learn from your mistakes and make a better one and sell that, no one will take you seriously with lending you money for investment until you sold one, your a kid, no one will believe in you unless kids do it all the time.
ancient mobiles are a good source of condenser type mic, they just wind up lying around, but mics on their own are 1£ bought online.
dude if you make anykind of profit expand and diversify
use a hammer even dont be silly, just one point, your circuit has two transistors mine has 1, transistors cost £2 so maybe you want the circuit with 1, plus thats a lot less soldering, its going to be tidier and simpler