Multi-Mode Up-Con-Trolled If Module

EE JULY/AUGUST 1987 The intermediate frequency (IF) moduleshowninFig.1accepts should also be possible in the drive a comparator from the FM detector output. Thereisnoneedforahighlevel only12kHz.TheRFandmixer SSB mode when a sufficiently 48MHz,andissuitablefor narrowbandfilterisincluded signal has already been filtered and occupies a bandwidth of receivingAM,FM andSSB (BW<500Hz). transmissions.CW reception 1 For radio- mixertoconverttheinputdown teletype(RTTY),itisbestto to455kHz,sincethe48MHz 015V --I1 15p FL8 = 453.5kHz FL9 = 456.5kHz stages in the TCA440 operate up to 50 M Hz,while the built-in 24 SUPPLEMENT 2 kHz 12 kHz USB r) LSB r)0 r L 1 FM I 1 N 4148 D2" 1N 4148 1N4148 470n D3" 1N 4148 [ 11 1115" C30 Tr 3 LMCS 41024 02 03 Squelch 0 AM 035 AGC 1 O 2 xAA119 X1 = 48MHz (3 overtone)//20p - 1 .52 mom A = D-A converter BC 549 C 470n C31 C32 C33 mim 100n 100n 136 1 N4148 025 R26 0 FL] LF • I/ 12 TCA 440 S041P 7p Ta BF 494 C55 1 1 47p 1119 020 41138 1213 C28 C58 2200/10V KVT" 1...