Before lining up the optical links, you have to take care that the input signals do not exceed the maximum levels (see Specifications on last page of this document)!
Start with 15dB attenuation settings on LFRX and LFTX card. In this configuration you should have approx. -2dB gain over the whole optical link. Due to variance of laser- and receive-diodes you might have some gain-spreading between different links. Depending on configuration of your sat-nms LFTX/RX frame you might have additionally more attenuation:
| option | option name | additional attenuation |
|---|---|---|
| n:1 redundant backplane | LFRED2 | 3dB (4.5dB switched) each frame |
| 50/75Ohm converter | LFCH...MNC75 | 0.7dB each frame |
| 1:4 splitter | LFRXv4 | 12.5dB |
| dual coupler | LFC10TX or LFC10RX | 1.5dB |
When connecting an occasional use antenna, point your dish to the satellite with the highest total power. This is to ensure not to generate a maximum level fault during normal operation.
Now decrease the attenuator setting (what increases the level on your link) of the LFTX transmitter card as long as a max. level fault is displayed. Now increase attenuator setting 2...3dB (this decreases the level on your optical link).
After that, adjust the attenuator setting in the LFRX receiver card to adapt the signal strength to your receiver equipment. For sure you have to watch out not to exceed the alarm level. If a RF max. level is displayed on the LFRX card, increase attenuator setting (that decreases output level of your optical link) until alarm disappears.