Olson Technology 7-OR - Manual (Page 6)

025-371546 Rev X1 Page 6
ALIGNMENT PROCEDURE
The 7-OR-RT optical transmitter’s OMI has been optimized with an RF drive level of about +8.0dBmV per carrier with
maximum loading (Six analog carriers) at the Laser RF Drive test point. Due to the number of different configurations
offered for the DiamondPoint 7-OR node, the amount of loss through the node can vary, therefore transmitter drive
levels should be set via the Laser RF Drive test point.
The chart below shows the drive levels are required for a given number of channels or QAM/QPSK loading. For
Example, if the transmitter is going to be loaded with three video channels, than the Laser RF Drive test point needs to
be approximately +10.5dBmV per carrier.
If QAM, QPSK, or similar digital loading is being used, than the loading is calculated by total bandwidth rather than the
number of channels. If loading from 5 to 29MHz, then the total input bandwidth is 24MHz. The chart below shows us that
24MHz of bandwidth is equivalent to four video channels, resulting in an Laser RF Drive test point level of +9.0dBmV
per channel.
Note: The numbers discussed throughout this manual are based on a typical DFB laser based transmitter. Transmitters
using FP lasers typically have RF levels 4 dB lower than DFB laser based transmitters. Transmitters using CWDM
lasers have RF drive levels about 6 dB lower than Standard DFB laser based transmitters.
Figure 2 - RF Drive Level & RF Drive Test Point Levels vs. Loading