RAMSEY URC1 PARTS LIST:
SEMICONDUCTORS
1 7805 5 volt power regulator (VR1)
1 145436 (or MC145436) 14 pin dip DTMF decoder IC (U5)
1 68HC705J2 20 pin dip
(white sticker marked
1 MAX7219 24 pin dip 8 digit display driver (U2)
1 MAX500 quad serial digital to analog converter (U7)
2 74HC595 serial latched shift registers (U1,U3)
1 DS1267 - 10 dual 10K digitally controlled potentiometer (U4)
6 seven segment LED displays (DSP1,2,3,4,5,6)
2 Red LEDs (D2,6)
2 1N4002 black epoxy diodes (D9, D10)
1 2N3904 NPN type transistor (Q2)
1
CAPACITORS
5 .01uF disk ceramic capacitors (marked .01 or 103 or 10 nF) (C2,5,7,10,11)
1 .1uF disk ceramic capacitor (marked .1 or 104) (C8)
1 470pF disk ceramic capacitor (marked 470 or 471) (C9)
1 100uF to 220uF electrolytic capacitor (C15)
3 10uF electrolytic capacitors (C4,6,13)
1 47uF electrolytic capacitor (C14)
RESISTORS
2 10K ohm
4 47K ohm
1 1M ohm
HARDWARE AND MISCELLANEOUS
1 3.579 Mhz crystal (Marked 3.579 or 3.579264) (X1)
1 1/8" PC mounted minijack (J1)
1 Power jack (J2)
1 Set hardware for regulator (1 screw and 1 nut)
1 34 pin right angle connector (CON1)
1 13 pin right angle connector (CON2)
1 3.9VDC lithium backup battery (B1)
1 Main PC board
1 Display PC board
1 20 Pin IC socket
1 4 inches of #24 bus wire
URC1 • 7