Kenwood PS-430 RL output 7800 port A6, BZ Buzzer output 7800 port A7, Reset output 7800 port B7

TS-440S

CIRCUIT DESCRIPTIO N

PES ,uPD7800

10 . PLL output bloc k

The PLL output block controls five PLL loops . The 500 kHz step PLL loop uses an MB87006 and the other PLL loops us e MN6147s .

The M387006 has two dividers : one for the PLL referenc e frequency and the other for a swallow type counter . Frequen - cy division data for the reference frequency is sent only on e when the TS-440 power is switched on .

Fig . 18 Reset circuit The MN6147 uses the PLL data format shown figure 19 .

8255( IC )

Por t

B4n,B 7

BOr B3 Address

Fig . 19 MN6147 PLL data

Since the MN6147 has latches as shown in Figure 20, onl y data following a change is output . GO data can be any dat a since it is used to transfer G2 and G7 data to the G8 latch .

11. Other output s

RL output (7800 port A6 )

This output signal controls transmission . When transmitting , this signal is "H" .

BZ (Buzzer) output (7800 port A7 )

This output signal makes the BZ circuit active . When this sig - nal is "H", the oscillator circuit operates .

RESET output (7800 port B7 )

This output signal resets the two 8255s and 8251 (option) . SBK output (8255 (IC2) port A6 )

This output signal switches the RF unit to prevent noise du e to PLL siwtching .

MT output (8255 (IC2) port A7 )

This output signal controls the AF output to prevent nois e due to PLL siwtching .

SCH output (8255 (IC2) port CO )

This signal controls the sub audible tone encoder . The sub - tone is activated whenever a transmit frequency in M-C H 90-99 has been selected, in the FM mode . A logic H acti- vates the encoder .

	coo x+100	xi0	xi	xi -
	le©©II~11 IINI	m®®m®mlllImm AEI2 3
	111111111111111111111 1
CP L	MIm G3	G4	G B	G G
			GS

DA 3

DA 2

DA I.__ .-~i DA 0

MN 614 7

Fig . 20 Data input terminal and programmable counte r

SW No . Hz

125

250

3	100	LS B
4	200

5400

62 5

750

8100USB

9200

10400

12. CAR compensation DIP switch

This switch is used to compensate the absolute frequenc y characteristic of the 455 kHz filter . The characteristic ca n be compensated within the range of — 400 Hz to + 375 Hz . LSB and USB can be compensated separately . When LSB i s compensated, FSK is also compensated .

Table 1 2

When all bits are off, -400 Hz is supplied for compensa- tion . When no compensation is required, bits 5 and 10 mus t be on .

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