U4221B

TELEFUNKEN Semiconductors

Rev. A1, 15-May-96

Preliminary Information

8 (12)

Information Regarding German Transmitter

Station: DCF 77,

Frequency 77.5 kHz,

Transmitting power 50 kW

Location: Mainflingen/Germany,

Geographical coordinates: 50

_ 0.1’N, 09_ 00’E

Time of transmission: permanent

0

5

10

15

20

25

30

40

50

55

0

5

10

coding

when

required

minutes

hours

day

of

the

week

month

year

35

45

21

22

23

24

25

26

27

28

30

29

31

32

33

34

35

12

48

10

20

40

P1

1

2

4

810

20

P2

Time Frame 1 Minute

( index count 1 second )

Time Frame

calendar

day

minutes

hours

20

sec.

s

Start Bit

Parity Bit P1

Parity Bit P2

Example:19.35 h

93 7527

Modulation:

The carrier amplitude is reduced to 25% at the beginning

of each second for 100 ms (binary zero) or 200 ms (binary

one) duration, excepting the 59th second.

Time Code Format: (based on information

of Deutsche Bundespost)

It consists of 1 minute time frames. No modulation at the

beginning of the 59th second to recognize the switch over

to the next 1 minute time frame. A time frame contains

BCD-coded information of minutes, hours, calendar day,

day of the week, month and year between the 20th second

and 58th second of the time frame, including the start bit

S (200 ms) and parity bits P1, P2 and P3. Further there are

4 additional bits R (transmission by reserve antenna), A1

(announcement of change-over to the summer time), Z1

(during the summer time 200 ms, otherwise 100 ms), Z2

(during standard time 200 ms otherwise 100 ms) and A2

(announcement of leap second) transmitted between the

15th second and 19th second of the time frame.