Here is how I got involved with Home Brew (HB) qrp rigs...

...Well it all started with this single pnp ~100mw gem on 40meters (7.1 mhz) crystall controlled. Basically a strong oscillator coupled to an antenna.  Using a old FT243 CW crystal  and 6volts, I worked W7KB in Phoenix AZ.. I got a 449!  After that I was hooked.  Notice the novice crystal holder feature... An appliance plug with the black goober.. probably silicon....and a perfectly wound inductor... but,  hey it worked...Original design  was from 101 easy HAM RADIO projects by Robert M.Brown and Tom Kneitel.  This was project 90, page 134, called  Flea-Power on 40 meters.  Still  works fine! Update:  I was looking again at this little gem and noticed a additional tank circuit.  Well, looks like I tweeked this from the recommended GE-2/RS2003 pnp and upgraded to a 2n3906... running 12v she puts out 168 clean mw's...Ahh to be a novice again..... Let's see... 68mw was almost a 3 dB increase!  Maybe half of one S-unit on the receiving end if I was lucky....Obviously a  thinking novice!