Antenna Faulty

The Antenna Faulty error may be displayed on any Meinberg device with an integrated GPS/GNSS or long-wave receiver (DCF77 PZF, MSF, WWVB).

This article examines the possible causes and provides help in isolating the root cause and solving the problem.

• There is no antenna connected.

• The connected antenna is not compatible.

• The connected antenna is defective.

• The coaxial cable is defective.

• The coaxial cable connector is loose.

• The clock module is defective.

• The DC/DC converter on the receiver module is defective (only applies to Meinberg GPS and GNS-UC receivers, i.e., receiver modules with GPS or GNS-UC in the module name such as GPS16x, GPS17x, GPS18x or GNS18x-UC)

• There is equipment installed between the device and the antenna (e.g., signal splitter, surge protector, converter or coaxial patch panel) which is defective or not properly connected (i.e. N-Norm screw thread crooked).

• The field strength of the received signal is too low (only applies to Meinberg long-wave receivers, i.e., receiver modules with PZF, WWVBor MSF in the module name, e.g., PZF511 or PZF18x).

• Electromagnetic or radio interference is disrupting the signal (only applies to Meinberg long-wave receivers, i.e., receiver modules with PZF, WWVBor MSF in the module name, e.g., PZF511 or PZF18x).

• Check the coaxial cable to ensure that there are no loose connections.
• GPS16x, GPS17x, GPS18x and GNS18x-UC receivers need to be connected to a Meinberg GPSANT antenna (https://www.meinbergglobal.com/english/products/gps-antenna-converter.htm). These receivers expect to receive an intermediate frequency of 35.4 MHz, which is only provided by the Meinberg GPSANT. If you wish to connect a standard GPS L1 antenna from another vendor to a GPS16x, GPS17x, GPS18x or GNS18x-UC receiver, the following converter needs to be connected between the antenna and receiver: https://www.meinbergglobal.com/english/products/gps-converter.htm
• If other equipment is installed between the antenna and the receiver, for example a surge arrester or splitter, circumvent that equipment temporarily by connecting the receiver directly to the antenna to see if the Antenna Faulty error persists. This can help to eliminate non-relevant factors and isolate the root cause.
• Measure the voltage at the antenna BNC connector of the receiver. This can be done using a multimeter by measuring between the central copper conductor and the outer shield/ground. There should be approx. 15V DC output via the GPS1xx or GNS18x_UC receiver's antenna connector. If 15V DC is measurable, connect the antenna cable and check if 15V DC is also measurable at the end of the cable to be connected to the antenna to determine whether there is a fault in the coaxial cable.
• Alternatively, if there is another Meinberg device with a GPS16x, GPS17x, GPS18x, or GNS18x-UC receiver module connected to another Meinberg GPSANT antenna at the same location, you can cross-check by swapping the antenna cables between the two devices, which can further help to isolate the root cause.

• Check the coaxial cable to ensure that there are no loose connections.
• GNS18x receivers need to be connected to a Meinberg Multi GNSS antenna (https://www.meinbergglobal.com/english/products/gps-glonass-l1-antenna.htm). Standard L1 antennas from other vendors can also be used as long as the technical specifications are suitable for this. If you would like to use an antenna from another manufacturer, please contact Meinberg Technical Support https://www.meinbergglobal.com/english/support/tech-support.htm and submit a data sheet for the antenna for verification.
• If other equipment is installed between the antenna and the receiver, for example a surge arrester or splitter, circumvent that equipment temporarily by connecting the receiver directly to the antenna to see if the Antenna Faulty error persists. This can help to eliminate non-relevant factors and isolate the root cause.
• Measure the voltage at the antenna SMA connector of the receiver. This can be done using a multimeter by measuring between the central copper conductor and the outer shield/ground. There should be approx. 5V DC output via the GNS18x receiver's antenna connector. If 5V DC is measurable, connect the antenna cable and check if 5V DC is also measurable at the end of the cable to be connected to the antenna to determine if there is a fault in the coaxial cable.
• Alternatively, if there is another Meinberg device with a GNS18x receiver module connected to another suitable antenna at the same location, you can cross-check by swapping the antenna cables between the two devices, which can further help to isolate the root cause.

• Check the coaxial cable to ensure that there are no loose connections.
• GNM18x receivers need to be connected to a Meinberg GNSS Multi Band antenna (https://www.meinbergglobal.com/english/products/gnss-multi-band-antenna.htm).
• If other equipment is installed between the antenna and the receiver, for example a surge arrester or splitter, circumvent that equipment temporarily by connecting the receiver directly to the antenna to see if the Antenna Faulty error persists. This can help to eliminate non-relevant factors and isolate the root cause.
• Measure the voltage at the antenna SMA connector of the receiver. This can be done using a multimeter by measuring between the central copper conductor and the outer shield/ground. There should be approx. 5V DC output from the GNM18x receiver's antenna connector. If 5V DC is measurable, connect the antenna cable and check if 5V DC is also measurable at the end of the cable to be connected to the antenna to determine if there is a fault in the coaxial cable.
• Alternatively, if there is another Meinberg device with a GNM18x receiver module connected to another Meinberg GNSS Multi Band antenna at the same location, you can cross-check by swapping the antenna cables between the two devices, which can further help to isolate the root cause.

• Check the coaxial cable to ensure that there are no loose connections.

• PZF receivers need to be connected to a Meinberg DCF77 antenna (https://www.meinbergglobal.com/english/products/dcf-antennas.htm AW02 or AI01).

• MSF receivers need to be connected to a Meinberg MSF receiver (https://www.meinbergglobal.com/english/products/dcf-antennas.htm AW02-60)

• If other equipment is installed between the antenna and the receiver, for example a surge arrester or splitter, circumvent that equipment temporarily by connecting the receiver directly to the antenna to see if the Antenna Faulty error persists. This can help to eliminate non-relevant factors and isolate the root cause.

• Measure the voltage at the antenna BNC connector of the receiver. You can measure this with a multimeter by measuring between the central copper conductor and the outer shield/ground. There should be approx. 5V DC output at the receiver's antenna connector. If 5V DC is measurable, connect the antenna cable and check if 5V DC is also measurable at the end of the cable to be connected to the antenna to determine if there is a fault in the coaxial cable.

• If the voltage measured is 5V DC as expected and testing of the coaxial cable does not reveal any problems, the problem may lie with the reception, as the Antenna Faulty error is also generated if the reception field strength is simply 0 %. There are a number of possible reasons why DCF77/MSF reception problems can occur:

• The DCF77/MSF antenna is not installed/aligned correctly. For optimal operation, the following criteria must be observed when installing a DCF77/MSF antenna:
  • The antenna should be mounted horizontally
  • The long side of the DCF77 antenna must be aligned in the direction of the transmission mast. For the German DCF77 signal the transmitter is located in Mainflingen next to Frankfurt Main. For MSF the transmitter is located near Anthorn, Cumbria.
  • Minnimum distance of 30 cm must be maintained from all metal objects
  • Meinberg recommends mounting the antenna outside of buildings. In general, this has the advantage that this usually increases the signal-to-noise ratio to electronic devices in buildings and increases reliability of synchronization is increased so significantly. Even if DCF77 reception is expected inside buildings is possible, the reception quality may be reduced due to shielding or attenuation.
• The transmitter itself may be offline (for example, for maintenance work).
  • For DCF77 reception, transmitter outages are documented in the log files of the Dcf77logs website at (https://dcf77logs.de/logs/). Dcf77logs is a privately run service not affiliated with the DCF77 service operator that monitors DCF77 reception and publishes reception logs. These logs can be cross-referenced with your own reception experience to determine whether time data was receivable at your location for the duration of the Antenna Faulty event. Each day has a separate log and, as long as time data is being correctly received by the Dcf77logs service, one line will be written to the log file per minute. Please note when cross-referencing data that the times logged by Dcf77logs are in CET/CEST, while Meinberg devices log events in UTC time.
  • For MSF reception, the National Physical Laboratory pre-emptively publishes advisories regarding expected downtime at (https://www.npl.co.uk/msf-signal).
• Atmospheric phenomena such as thunderstorms can interfere with reception.
• Equipment such as electric motors, electric generators, or air conditioning systems can generate strong electromagnetic fields can disrupt DCF77 signal reception.
• Other nearby antennas/transmitters (e.g., directional radio) can cause interference.
• High-voltage cables passing over the antenna are also a source of potential interference.
• If the antenna is installed indoors, reinforced concrete and insulated glazing can impair reception quality.

Contact Meinberg Technical Support: https://www.meinbergglobal.com/english/support/tech-support.htm

— Manuel Schäfer manuel.schaefer@meinberg.de, last updated 2022-07-19 14:01