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6. Logic Table for operation

6.1 I/O Conditions

Input Pin Condition

Output Pin

Condition

Result/Function

D0-D5

PTT

PTL

CTCSS

Tone in

DECODE

MONIT R

0

Tone

Transmitter

Enabled

TX Audio

Path

Enabled

Tone

Decoder

Enabled

RX Audio

Path

Enabled

Notes

Tone

0

0

X

0

1

Yes

Yes

No

No (bias)

1

No Tone

0

X

X

0

1

No (bias)

Yes

No

No (bias)

2

Tone

1

0

No

0

1

No (bias)

No

Yes

No (bias)

3a

Tone

1

1

No

0

1

No (bias)

No

Yes

Yes

3b

Tone

1

X

Yes

o/c

0

No (bias)

No

Yes

Yes

4

No Tone

1

X

X

o/c

0

No (bias)

No

Yes

Yes

5

Table 3: Combinations of input/output conditions

Notes: o/c = Open circuit

X = don’t care

1.

Normal tone transmit condition.

2.

3a.

Normal decode standby.

3b.

Normal decode standby with PTL used to enable audio.

4.

Normal decode of correct CTCSS tone condition, PTL has no effect.

5.

Notone programmed in RX mode, tone transmit O/P (o/c). RX audio path enabled.

6.2 CTCSS Programming

Tone

Programming Inputs, Switch (Solder Jumper)

Nominal

Frequency (Hz)

MX465

Frequency (Hz)

D5

(E6)

D4

(E5)

D3

(E4)

D2

(E3)

D1

(E2)

D0

(E1)

Hex

67.0

66.98

-0.029

111111

3F

69.3

69.32

0.024

111001

39

71.9

71.901

0.001

011111

1F

74.4

74.431

0.042

111110

3E

77.0

76.965

-0.046

001111

0F

79.7

79.677

-0.029

111101

3D

82.5

82.483

-0.021

011110

1E

85.4

85.383

-0.020

111100

3C

88.5

88.494

-0.007

001110

0E

91.5

91.456

-0.048

111011

3B

94.8

94.76

-0.042

011101

1D

97.4

97.435

-0.036

111010

3A

100.0

99.96

-0.040

001101

0D

103.5

103.429

-0.069

011100

1C

107.2

107.147

-0.05

001100

0C

110.9

110.954

0.049

011011

1B