Table 9 Troubleshooting the Receiver
Problem | Possible Cause |
|
|
1. Lack of RF signal | If a spectrum analyzer or power meter | ||
| present at Receiver, | is not available then use a DVM and | |
| yet optical power is | adjust the gain control for RF signal | |
| functioning. | strength (RSSI) so that the reading is | |
|
| > 0.2VDC. (See Table 5 7870R Receiver | |
|
| Pinout on page 21). | |
|
| Conclusion: If signal still not present | |
|
| then transmitter input stage amplifier | |
|
| or receiver amplifier is defective. | |
|
| Contact factory. | |
2. | No optical power, | a. | Transmitter is not functioning, see |
| LED not | b. | above. |
| illuminated. | There is a break or severe bend in | |
|
|
| the fiber optic cable. Use an optical |
|
|
| power meter or another |
|
|
| functioning receiver unit to verify |
|
|
| optical power coming down the |
|
| c. | fiber. |
|
| The connector is dirty. Clean it. | |
|
| d. | Optical power too low, too many |
|
|
| splits, too long a distance (thus |
|
|
| exceeding optical budget). System |
|
|
| may still function without LED |
|
|
| illuminated although at reduced |
|
|
| performance. |
3. | Optical power light | Damaged (leaky) photodiode. Unit | |
| illuminated with | may still function, otherwise contact | |
| disconnected optical | Factory for service. | |
| input. |
|
|
4. The RF LED is not | Verify that the RF signal strength | ||
| illuminated. | (RSSI) is <0.2° VDC. | |
page 26 | Document no. |
