Low Frequency Time SIgnal Receiver - DCF77  77.5KHz

Information sheet available by email (please send me your e-mail address if you require a copy)

DCF77 is a German longwave time signal and standard-frequency radio station. It started service as a standard-frequency station on 1 January 1959. In June 1973, date and time information was added.

Its primary and backup transmitter are located at 50°0′56″N 9°00′39″E in Mainflingen, about 25 km (20 mi) south-east of Frankfurt am Main, Germany. The transmitter generates a nominal power of 50 kW, of which about 30 to 35 kW can be radiated via a T-antenna.

Very sensitive and capable time signal receiver module with antenna tuned to time signal transmitter DCF77.

In the North East of England I can easily receive the time signals.  See video.

I have connected the data output line to an ESP-32 VROOM module and made a small test programme to detect data pulses from the radio module - first steps in decoding the acutal date and time information.  Currently, early stages of development but a nice little project to improve my coding and experience with working with the ESP-32 module.

Transmitter Information:

Location    Mainflingen longwave transmitter, Mainflingen, Germany

Coordinates    50.01556°N 9.01083°E

Elevation    113 m (370 ft)

Operator    Media Broadcast GmbH on behalf of the PTB

Frequency    77.5 kHz

Power    50 kW

Began operation    1 January 1959; continuous date and time information was added in June 1973

Official range    2,000 km (1,200 mi)

Website    DCF 77

The antenna induction signal is sent to the IC for amplification, demodulation, and then identified by the MCU.

Technical Specifications

Product number: DCF-3850N-800

RCCM category: DCF/77.5KHz single frequency module

PCBA size: 21.5x13.5x1.0mm/FR4

Antenna size: AP3x8x50mm/High Q

Nominal frequency: 77.5KHz±300Hz

Sensitivity: 28±2dB

Receiving IC: SP6007

       • Operating voltage: 1.1...3.3 V

       • Current consumption: 85 µA max

       • Receiving frequency: 77.5KHz

       • connect:

             ⇒ Ground = Pin G

             ⇒ Operating Voltage = Pin V

             ⇒ data = pin T

             ⇒ Power On/Off = Pin P1

       • Important note:

             ⇒ PIN P1 is an on/off switch and must be set to logic low.

Package Included:

1*Receiver module