Front Panel Indicator Status
WWVB reception problems are often detected by the status of the front panel Antenna, Signal and Time Sync lamps. Whenever any of these lamps are red, a problem exists which may prevent WWVB synchronization. In addition to understanding the error conditions as shown in the table below, it is helpful to perform additional testing before performing corrective actions using the built-in test mode, analyzing the internal signal quality log, and measuring the signal strength with a multimeter and the AC output from the amplifier with an oscilloscope.
| Indicator |
What it means |
Explanation |
| Antenna Status |
| Green |
Antenna connected and cable is good |
The lamp is driven by a comparator monitoring the DC voltage present on the Antenna connector. The voltage powers the models 8208/8208A active antennae and model 8207 inline preamp (if used). The comparator window ranges from 2 to 8 VDC. |
| Red |
Antenna voltage is outside the range of 2 to 8 VDC |
Antenna cable is open or a short exists. The cable may have been accidentally cut or a connector has a bad crimp, or lightning has damaged the hardware. See troubleshooting WWVB antenna hardware. |
| Signal Status |
| Green |
The receiver is phase-locked |
The receiver is phase-locked to the WWVB carrier. |
| Blinking Red-Green |
A VCXO adjustment is needed |
Contact Spectracom tech support. |
| Red |
Receiver has lost lock to the WWVB carrier |
An occasional loss of lock can be considered normal. Typically, the receiver re-acquires phase lock within minutes. A problem, such as ice accumulation on the WWVB antenna, can be the cause of a longer term loss of lock. It is not considered normal for the receiver to lose lock on a regular basis. The problem can be related to interference or antenna alignment. If the lamp is constantly red, the problem can be related to the antenna, receiver or extreme saturation. Measure WWVB signal strength and/or amplifier output. |
| Time Sync Status |
| Green |
Normal operation |
Proper time codes are received. |
| Red |
Unable to achieve or maintain WWVB synchronization |
One of the following conditions exists:
- Set-up is not complete or a power failure has occurred.
- The receiver has lost phase lock to WWVB for a period greater than one hour.
- The receiver has not decoded a minimum of five consecutive error-free minutes over the past 24 hours.
Typically the problem is caused by local interference. Try the test mode feature and check for sources of WWVB interference. |