Kenwood YK-88SN, PS-50, SP-430, PS-430, VS-1 Circuit Description, Fig Control circuit block diagra m

TS-440S

CIRCUIT DESCRIPTION

pulses and U/D signals from two clock signals which are 90 ° out of phase with each other, and sends the pulses and sig- nals to the 7800 . A clock pulse interrupts the 7800 and a U/D signal causes the 7800 to perform a count up or dow n operation for each step . If fast rotation occurs, the 780 0 processes several steps of PLL data at one time .

Voltages from the RIT and IF shift VRs are converted fro m analog to digital by the A/D convertor IC (4052) and fed int o the 7800 . The voltages are used to drive the display and ar e reflected in the PLL data .

The digital control circuit contains two 8255's for extende d I/O . The 8255 in control unit A is an outputonly element an d the 8255 in control unit B is an inputonly element for ke y scan and static data . The output 8255 emits VS-1 signals,

PLL data for the 6147, clock signals, and 1 MHz LED data . The input 8255 receives key scan data such as panel switc h data and DIP switch data for CAR compensation . It als o receives static data which cannot be entered as a portion ke y scan data .

The 7800 outputs four bits of band and mode informatio n (11 bands in the frequency range from 30 kHz to 30 MHz) . Each time the 8251, used as the interface to a personal com - puter, receives one byte of data, the 7800 is interrupted an d reads the data from the 8251 . The 7800 analyzes any com- mand in the data . In response to the command, the 7800 controls setting or writes data to the 8251 as required . The 8251 serially sends one byte of data including a start bit, syn - chronizing to a 4800 Hz clock signal .

RIT IF-SNIF T

	Made lnfnrmaYYO, :A LEO) e		/0 control	,E,
	_SB,US0,CW,AM,FM,FSH1		)CIOAk,por',select t
En<mer count pufse	Tx	e'•al 0,1	Seeial o	t ,O)
	Outdo.		;clock dot)-,
Enc .. u/C s .9no l
	Band ,nformofion		(PLC .195)58,FIP . 630 0
n ock s,gno l
	Enable 2;		Power down IPO I
A/O converter data
	(PLL :145158,Fi P .6300 1
	Peounwa l
	1825`IAI,l8)e825) )
	PIP	C

85-I	converter C S	Ines,	I	L	_ J Rs-232C
		Lack S W
(Address s rt)	Ton e conirallTON )	AT S W
AF Mole (MY)	LE D	MIC UP/DOWN S W
PP Mule 1590)	(M SCR, IMU,	PTT SW
PLL do	Lock )	vs-I	dos,.
.. .too,	dotal	Key sca n
		0 key
		V, SCAN, CLEA R
		tT , . .,N. ENT
		A/ Et,	T,T-FSE T
		B	SPRIT, A= 9
			DOWN
		VOICE U
OPTION		\CAN SW ipra NOn		/ '

Vs -

Fig . 13 Control circuit block diagra m

18