Part    		Type

IC1			78L05
IC2			HT9170B
IC3			PIC16F627A programmed with our DTMF display code
D1			1N4148
XT1			3.579MHz crystal
XT2			not fitted
R1*			4K7
R2, 4			not fitted
R5			wire link
R3*			270K
R6*			1K
R7			330K
R8, 9, 10, 11, 12, 13	10K
VR1			10K variable
C1, 5, 6		100nF (marked 104)
C2			not fitted
C3, 4			22pf
C7, 8, 9		1uF (marked 105) observe polarity
CN1, 6			3 pins
CN2			7+7 Pins (supplied as 3+3 & 4+4)
CN3			not fitted


Also supplied:-

DTMF display PCB Iss A
Crystal insulator pad
2 x 10K for alternative input configuration
3+3 & 4+4 sockets for display
LCD display
4 x nuts, bolts and spacers

*Note

Only fit R6 if using an electret microphone as input.

Only fit R1 & R3 as 4K7 & 270K for use with a microphone,
otherwise fit R1 & R3 as 10K or calculate a custom input configuration
from HT9170 datasheet.