RF Configuration Options | What are the differences between LN and LN+?

The key difference between LN and LN+ is that LN+ will have better long-term performance—for example, a better Allan variance for a longer time. For short-time performance, they are identical. 

Here's another example...Option LN adds a 100 MHz OCXO on the ref board, applying to all channels. Option LN+ will do the same. The only difference is that the OCXO will have better long-term stability. 

You can incorporate either LN or LN+. Options can't be combined and priced per unit.