FIRST test proffesional receiver with tda7540!
ISS is system selectivity inteligent . INTELIGENT by the NARROW extrem circuit . ATTENTION .. with 3X230 khz this receiver behave at 1 receiver with 3X180khz .. is incredible , no LOL .. serious .
IN original context radio is with 3X180khz - calibration with 132khz .. no coment .. wery narrrow , correct is 138khz .. and this radio with 3 X180 is equivalent with 3X150khz
FINALLY
TEST by me , 3X150khz filter , comportament is real at 3X130 FI filter .. wery narrow
DETECT : 106.0 near 105.8 mihz .. 3.5km radio .. oberon radio max
103.3Mhz silistra near 4.4km stundent fm 103.4Mhz ...
This ISS is super .. not equivalent by tuner home .. is super and VERY SUPER!
http://www.trilulilu.ro/dxfmromania/d74190b44b9234
enjoy test , modifications .. ! , and TEST with 5501 TEST with 8dB gain amplifier from interior PCB .. blkue dispaly radio