Here is a simple mod that will produce better performance from the very fine Murania radio...It is completely reversible and requires no hacking of the radio...
I live 5 miles from a 50kW AM station which tends to overload the detector in the TA7642 IC...Here's the fix...
FLOAT the wiper lug of R3 Place a jumper between the PADS for the R3 wiper and the high side of R3 Lift the leg of R1 that intersects with R2 and R3 Connect a jumper between the floated leg of R1 and the wiper of R3
Done...
This allows R3 to control the gain of the detector stage in the TA7642...The audio amp runs wide open...Adjust R3 for the best sounding audio...R3 now acts similar to a regenerative control where there is both volume and gain reaction...
This mod comes from my own experimenting and information gleaned off the Internet...Give it a try...I think you'll be pleased with the results...