boborachman project S-139 Pre amp mic use IC LA3220 for Radio SSB Bilateral Tranciever BC547
The original design at Radio SSB Bilateral Tranciever is use pre amp mic with tr c828, My re design how about replace with ic LA3220 ? i tracking from PCB at local store online (you can find that pcb use search key LA3220) AF AMP speaker use LA 4182 or another similar mini amplifier such as TEA2025, just configure as stereo / two speaker 4watt or set up as BTL to increase power output use larger speaker. at local store ist cheap IC. about 2rb. the kit preampmic (was use for preamphead cassete player) about 4rb )New old stock) then you can modif it into mono modul (cut a half) that ist my idea.. to be continue